Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/11/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
820 PM MST SUN MAY 10 2015
.SYNOPSIS...
NEAR NORMAL TEMPERATURES WITH PLENTY OF SUNSHINE CAN BE EXPECTED
THROUGH THURSDAY ACROSS THE DESERT SOUTHWEST. FRIDAY THROUGH SUNDAY
...ANOTHER UNSEASONABLY COOL STORM WILL ARRIVE...USHERING IN MUCH
COOLER TEMPERATURES...BREEZY CONDITIONS...AND HEIGHTENED CHANCES FOR
RAIN.
&&
.DISCUSSION... NEARLY CLOUDLESS SKIES WERE NOTED ACROSS OUR FORECAST
AREA THIS EVENING...SOUTHEAST CA TO SOUTH CENTRAL AZ...AS A
TRANSITORY HIGH PRESSURE SYSTEM WAS BUILDING INTO THE AREA. THE HIGH
PRESSURE SYSTEM WILL RESULT IN WARMER AFTERNOON TEMPERATURES
MONDAY...A FEW DEGREES ABOVE NORMAL OR IN THE MID 90S.
THE TRANSITORY HIGH PRESSURE SYSTEM WILL BE FOLLOWED BY A WEAK
PACIFIC DISTURBANCE FORECAST TO MOVE INTO AZ BY TUESDAY EVENING. LOW
LEVEL SOUTH WINDS AHEAD OF THIS SYSTEM WILL PROVIDE ANOTHER WARM
AFTERNOON TUESDAY...ALBEIT 1 TO 2 DEGS LOWER THAN MONDAY.
CONSIDERABLE HIGH CLOUDS WILL ALSO SPREAD INTO THE REGION. 500 MB
HEIGHT FALLS WITH THIS SYSTEM WILL BE CONFINED TO FAR SOUTHEAST AZ
WHERE A SLIGHT CHANCE OF SHOWERS ARE FORECAST LATE TUESDAY
AFTERNOON AND EVENING.
OTHERWISE DRY AND WARMER FORECAST FOR OUR AREA LOOK OK FOR NOW. NO
UPDATES PLANNED. PREVIOUS DISCUSSION BELOW STILL APPLIES.
.PREVIOUS DISCUSSION...225 PM MST...
BENIGN WEATHER ACROSS OUR FORECAST AREA THIS AFTERNOON WITH NEARLY
ZERO CLOUD COVER. SOME WEAK ECHOES HAVE DEVELOPED OVER THE RIM/WHITE
MTNS RESULTING IN SOME THUNDER. BASED ON HRRR TRENDS/FLOW NOT
EXPECTING THAT ACTIVITY TO IMPACT OUR AREA.
TAKE-HOME MESSAGE AT THIS TIME IS NEAR/ABOVE NORMAL TEMPERATURES
EARLY IN THE WEEK WILL GIVE WAY TO ANOTHER ROUND OF UNSEASONABLY
COOL AND SHOWERY WEATHER BY FRIDAY THAT WILL LAST THROUGH THE
WEEKEND.
FIRST HALF OF THE WEEK...NOT MUCH TO DISCUSS. SHORT TERM MODELS ARE
LOCKED INTO THE DEPARTING LOW AND INCOMING SHORT WAVE RIDGE YIELDING
LITTLE DIFFERENCE IN FORECAST MAX/MIN TEMP VALUES. TUESDAY COULD BE A
BIT INTERESTING AS A SHORT WAVE RIDES THE SOUTHERLY FLOW AND ADVECTS
SOME MOISTURE INTO EASTERN ARIZONA...THOUGH POTENTIAL IMPACT TO OUR
FORECAST AREA IS MINIMAL AT THIS TIME.
GLOBAL ENSEMBLE DATA AND DETERMINISTIC RUNS OF EC/GFS ARE IN REALLY
GOOD AGREEMENT ON THE BROAD DETAILS FOR FRIDAY THROUGH SUNDAY.
ANOTHER LARGE CLOSED LOW...OF WHICH THE CURRENT ENERGY IS NEAR THE
ALEUTIAN ISLANDS...WILL MOVE INTO SOCAL AND AZ FRIDAY. THERE WILL BE
A LEADING SHORT WAVE WHICH WILL LIKELY GIVE US OUR BEST CHANCE OF
RAIN...CURRENTLY TIMES TO ARRIVE DURING THE DAY FRIDAY. WE COULD SEE
SOME ENHANCED WINDS AS THE SYSTEM LAYS INTO ARIZONA...IF HUMIDITY
VALUES ARE STILL LOW WHEN THIS HAPPENS WE COULD HAVE A PERIOD OF
CRITICAL FIRE WEATHER CONDITIONS. SOMETHING TO WATCH.
BROAD TROUGHING WILL CONTINUE THROUGH THE WEEKEND. HARD TO SAY
IF/WHEN SHOWERS WILL OCCUR AS THAT/LL HINGE ON THE FINER DETAILS OF
SHORT WAVE ENERGY ROTATING AROUND THE PARENT LOW. THERE DOES SEEM TO
BE QUITE HIGH CERTAINTY THAT WE/RE IN FOR ANOTHER WEEKEND IN MAY OF
COOL TEMPS. CURRENT FORECAST HIGH TEMPS ON SATURDAY RANGE FROM 10 TO
20 DEGREES BELOW NORMAL. AN ANALYSIS OF HISTORICAL PHOENIX RECORDS
INDICATE THAT THERE HAVE ONLY BEEN FIVE INSTANCES/YEARS WHERE THE
MONTH OF MAY HAD TWO OR MORE SATURDAYS WITH A HIGH TEMP BELOW 80F
/LAST WAS IN 1971/. WITH A CURRENT FORECAST HIGH OF 78 FOR THIS
COMING SATURDAY...2015 WOULD BE THE SIXTH.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND
KBLH...
DRY WESTERLY FLOW ALOFT WILL PROVIDE CLEAR SKIES AND LIGHT WIND
UNDER 8 KNOTS THROUGH AT LEAST 22Z MONDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WARM TEMPERATURES AND LOW HUMIDITY VALUES WILL BE ESTABLISHED MID-
WEEK BUT THAT WILL CHANGE BY FRIDAY AS ANOTHER UNSEASONABLY COOL
STORM SYSTEM ENTERS THE SOUTHWEST. BREEZY WINDS WILL ACCOMPANY THE
SYSTEM AS IT MOVES IN THURSDAY AND EARLY FRIDAY AND COULD COMBINE
WITH STILL DEPRESSED HUMIDITY VALUES FOR A PERIOD OF CRITICAL FIRE
WEATHER CONDITIONS. AS THE SYSTEM EASES IN LATER FRIDAY...
TEMPERATURES WILL DROP AND HUMIDITY VALUES WILL INCREASE. CHANCES
FOR WETTING RAIN...ESPECIALLY ACROSS CENTRAL ARIZONA...WILL ALSO
INCREASE. THIS WEATHER PATTERN WILL LIKELY REMAIN THROUGH THE
WEEKEND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...VASQUEZ/INIGUEZ
AVIATION...VASQUEZ
FIRE WEATHER...INIGUEZ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
930 PM PDT Fri May 8 2015
.Synopsis...
Dry weather will return for the weekend with above normal
temperatures. A weak system will bring a chance for showers and
possibly thunderstorms to the northern mountains and portions of
the Sierra for Monday into midweek. Another system may move in
Thursday into Friday with another chance for showers and
thunderstorms.
&&
.Discussion...
Backwash/wrap around clouds and showers/T-storms worked their way
SWwd from Wrn NV into our NErn zones late this afternoon and early
this evening. The activity is diminishing...with radar indicating
scattered light showers moving SWwd from the Nrn mtn zones...NE Sac
Vly Foothills...and into or towards the Nrn Sac Vly and E side of
the central Sac Vly. This is about on track with the HRRR column max
REF prog...which ends precip by 06z-07z. The showers should
dissipate by the time they reach the SAC area...but the associated
cloud cover from this convection will spread into the area...before
it erodes overnight.
Little...if any...convection expected to develop in our CWA on Sat
as the cyclonic flow from the departing upper low shifts Ewd into NV
and ridging from the W begins to build into Norcal. After max temps
reached the mid 70s south to mid 80s north in the Central Valley
today...ridging will bring some warming to the valley with highs in
the 80s...maybe near 90 in the Nrn Sac Vly on Sat.
An approaching upper trof may lead to a chance of showers/T-storms
over the coastal range and Nrn mtns on Sun. Otherwise...increasing
onshore gradients may lead to some cooling throughout the Wrn
portion of the CWA on Sun...but not necessarily in the Siernev until
Mon. JHM
.Previous Discussion...
High pressure then briefly builds in for the weekend. This should
end the chance for precip by Saturday morning with a return to
mostly sunny skies and above normal temperatures. Afternoon highs
will max out in the 80s in the valley and 50s to 60s in the
mountains. Another weak system is progged to drop SE from the Gulf
of Alaska and into the region by Monday. Moisture will be limited
but forcing might be enough to generate some showers, mainly across
the northern mountains. As previous shift mentioned, chances for
thunderstorms across the Sierra during this timeframe were a bit
overdone given current model solutions and limited instability. Have
cut back chances in this area to better mirror latest guidance.
Elsewhere, only tangible effect of this system will be increased
cloud cover and cooler temperatures.
CEO
.Extended Discussion (Tuesday through Friday)
Another upper level low is forecast to approach the West Coast
by Tuesday and track over northern/central CA through the end of
the week with the models in decent agreement. Any upper
low/synoptic disturbance this time of year usually translates to
showers and/or thunderstorms. Thursday and Friday look to have the
most widespread chances of thunderstorms due to the low moving
eastward over the region. The oblong low even has a negative tilt
(orientated NW to SE from top to bottom) Thursday that should
generate good upward vertical motion typically resulting in
stronger, more widespread, storm activity. JClapp
&&
.Aviation...
Mainly VFR conditions across Valley TAF sites the next 24 hours.
MVFR/IFR conditions with scattered showers/isolated ts over the
Sierra through 06z.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND JUNCTION CO
643 PM MDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 643 PM MDT SUN MAY 10 2015
TRAILING SHORTWAVE AND VORTICITY MAXIMA AXIS MOVING OVER EASTERN
UT EARLY THIS EVENING WILL MOVE ACROSS THE AREA OVERNIGHT. WITH
THE LIFT AHEAD OF THE SHORTWAVE NOT CLEARING THE DIVIDE UNTIL
AFTER 09Z...AND CONSIDERING CURRENT RADAR/SATELLITE TRENDS
SHOWING WHICH SHORT RANGE MODELS SEEM TO HANDLE PRETTY WELL...HAVE
UPDATED THE FORECAST TO BOOST CHANCE OF PRECIPITATION THROUGH 06Z
FOR MUCH OF EASTERN UT AND WESTERN CO...AND THEN HELD ON TO HIGHER
CHANCES OVER THE CENTRAL MOUNTAINS PAST MIDNIGHT. ISOLATED THUNDER
CAN BE EXPECTED THROUGH MID EVENING AND GUSTY NW WINDS WILL BE
COMMON NEAR ANY OF THE SHOWERS. LIGHT ACCUMULATIONS OF SNOW LIKELY
AT THE HIGHER ELEVATIONS...SOME OF WHICH WILL AFFECT PASSES.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 323 PM MDT SUN MAY 10 2015
NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE
NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA
THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS
TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT
INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING
QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING
MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS
IN THE SHORT TERM.
FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR
INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW
RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS
EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE
HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT
AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP
FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT.
NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION
WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST
BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE
SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE
WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK.
ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST
WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR
ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE
QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID
SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN
UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS.
DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES
BELOW NORMAL.
DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL
SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST
PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON.
OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD
COVER IS BALANCED BY WAA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 PM MDT SUN MAY 10 2015
THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A
STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE...
ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE
ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE
CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON
WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO
GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL
DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA
MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE
EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING
HIGHS AROUND 5 DEGREES ABOVE NORMAL.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND
MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A
SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST.
EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION
WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH
ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON
THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD
ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE.
AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS
LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL
CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST
FLOW PERSISTS.
HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC
MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED
FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF
MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH
INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS
DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST
HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS
IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND
ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE
LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA
EVENTUALLY REACHING THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 543 PM MDT SUN MAY 10 2015
SCATTERED BUT SHORT LIVED -SHRA (SNOW LEVEL AROUND 7-8K FEET) WILL
PERSIST THROUGH 04Z-06Z AS THE LAST SHORT WAVE SWEEPS ACROSS THE
REGION THIS EVENING. LOW MOUNTAIN CIGS WILL GRADUALLY IMPROVE
BETWEEN 06Z-15Z OVERNIGHT. WIDESPREAD VFR CONDITIONS WILL PREVAIL
AFTER 15Z MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...BEN
SHORT TERM...TGR/NL
LONG TERM...NL
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
543 PM MDT SUN MAY 10 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 323 PM MDT SUN MAY 10 2015
NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE
NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA
THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS
TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT
INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING
QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING
MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS
IN THE SHORT TERM.
FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR
INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW
RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS
EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE
HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT
AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP
FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT.
NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION
WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST
BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE
SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE
WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK.
ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST
WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR
ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE
QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID
SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN
UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS.
DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES
BELOW NORMAL.
DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL
SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST
PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON.
OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD
COVER IS BALANCED BY WAA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 PM MDT SUN MAY 10 2015
THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A
STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE...
ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE
ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE
CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON
WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO
GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL
DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA
MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE
EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING
HIGHS AROUND 5 DEGREES ABOVE NORMAL.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND
MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A
SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST.
EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION
WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH
ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON
THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD
ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE.
AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS
LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL
CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST
FLOW PERSISTS.
HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC
MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED
FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF
MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH
INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS
DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST
HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS
IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND
ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE
LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA
EVENTUALLY REACHING THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 543 PM MDT SUN MAY 10 2015
SCATTERED BUT SHORT LIVED -SHRA (SNOW LEVEL AROUND 7-8K FEET) WILL
PERSIST THROUGH 04Z-06Z AS THE LAST SHORT WAVE SWEEPS ACROSS THE
REGION THIS EVENING. LOW MOUNTAIN CIGS WILL GRADUALLY IMPROVE
BETWEEN 06Z-15Z OVERNIGHT. WIDESPREAD VFR CONDITIONS WILL PREVAIL
AFTER 15Z MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...TGR/NL
LONG TERM...NL
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1115 PM MDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 906 PM MDT FRI MAY 8 2015
UPDATED TO EXPIRE THE TOR WATCH AND ADJUST POPS ETC
BASED ON CURRENT OBS AND LATEST HI RES GUIDANCE. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 210 PM MDT FRI MAY 8 2015
CURRENTLY...SIGNIFICANT INSTABILITY HAS DEVELOPED ACROSS THE
SOUTHERN I-25 CORRIDOR WHERE STRATUS CLEARED EARLY...WITH LAPS
CAPES RUNNING OVER 2000 J/KG. 0-6KM SHEAR SUFFICIENT FOR ROTATING
CONVECTION...WITH 2 PERSISTENT SUPERCELLS SOUTH OF PUEBLO AS OF
2130Z. STRONGEST CONVECTION NEXT 1-3 HOURS WILL LIKELY BE ACROSS
PUEBLO/LAS ANIMAS/CROWLEY/OTERO COUNTIES WHERE INSTABILITY IS
GREATEST...WITH HRRR KEEPING STRONG CONVECTION GOING OVER
SOUTHEAST PUEBLO COUNTY WELL INTO THE EVENING. FARTHER NORTH
AROUND COLORADO SPRINGS...CLOUDS AND EARLY MORNING CONVECTION HAVE
HELD DOWN INSTABILITY SOMEWHAT....THOUGH STORMS HAVE BEEN ABLE TO
PRODUCE VOLUMINOUS SMALL HAIL ONCE AGAIN. MOUNTAINS WILL SEE ONLY
ISOLATED STORMS...AND FAR EASTERN PLAINS NEAR THE KS BORDER LOOK
TOO STABLE FOR MUCH DEEP CONVECTION...AT LEAST INTO THE EARLY EVENING.
TONIGHT...CONVECTION ALONG I-25 CORRIDOR WILL CONTINUE PAST
SUNSET...WITH WEAKENING STORMS SHIFTING TOWARD THE KS BORDER
BY MIDNIGHT. SEVERE THREAT WILL CONTINUE SOUTHERN I-25
CORRIDOR...WITH TORNADO WATCH UNTIL 03Z LOOKING REASONABLE. MAY
SEE SOME SORT OF MCS LIFT OUT OF THE TX PANH SAT MORNING....AND
WILL INCREASE POPS OVER THE PLAINS TO ACCOUNT FOR THIS
POSSIBILITY. LIFT INCREASES OVER CONTINENTAL DIVIDE AS UPPER LOW
APPROACHES...WITH AT LEAST SOME LIGHT SNOW OVER THE HIGHER PEAKS
BY MORNING.
SATURDAY...STILL NOT A CLEAR CUT SOLUTION REGARDING POSITION OF
SURFACE LOW AND HOW FAR WEST LOW LEVEL MOISTURE/INSTABILITY WILL
REMAIN IN THE AFTERNOON. GFS/ECMWF LIFT SURFACE LOW AND WARM FRONT
NORTH OF THE PALMER DIVIDE BY AFTERNOON WITH DRYLINE PUNCHING INTO
KS BY SAT EVENING. LAST COUPLE RUNS OF THE NAM KEEP THE SURFACE
LOW SOUTH OF KLHX UNTIL EARLY EVENING...WHICH KEEPS SURFACE AXIS
OF DEEP INSTABILITY/MOISTURE FARTHER WEST AND ALLOWS AT LEAST
SOME MODERATELY UNSTABLE AIR TO WRAP BACK INTO PUEBLO/EL PASO
COUNTIES LATE. WILL LEAN TOWARD THE HIGHER TERRAIN RESOLUTION NAM
AT THIS POINT AS CLIMATOLOGY SUPPORTS ITS SURFACE LOW POSITION
NEAR KLHX...AND POSSIBLE EARLY MORNING CONVECTION ALONG THE KS
BORDER MAY PUSH MOIST AIR WESTWARD FOR A TIME SAT MORNING. IF
MOISTURE HOLDS IN PLACE...MASSIVE SHEAR (0-6KM SHEAR 60-70 KTS)
WILL LEAD TO SEVERE STORMS OVER THE FAR EASTERN PLAINS WITH EVEN
SOME STRONGER STORMS POSSIBLE BACK TOWARD PUEBLO AND COLORADO
SPRINGS AS STRONG LIFT WRAPS BACK AROUND THE UPPER LOW.
OVERALL...WILL KEEP POPS IN PLACE ALL DAY OVER THE FAR EASTERN
PLAINS...WITH CONVECTION POSSIBLE EARLY IN THE MORNING AND A
SECOND ROUND OF STORMS IN THE AFTERNOON. EASTERN MOUNTAINS/I-25
CORRIDOR WILL SEE A DRY PERIOD THROUGH THE MORNING AS WLY
DOWNSLOPE INCREASES...THEN AN INCREASING CHANCE OF PRECIP BY
AFTERNOON AS LOW LIFTS OUT AND STRONGER LIFT DEVELOPS UNDER THE
TROWAL. REMAINING MOUNTAINS AND VALLEYS WILL SEE SCT TSRA...WITH
HEAVY SNOW OVER THE HIGHER PEAKS. KEPT WINTER STORM WATCH IN PLACE
FOR CENTRAL MOUNTAINS SAT...AND HOISTED A NEW WATCH FOR THE SUMMIT
OF PIKES PEAK WHERE 1 TO 2 FEET OF NEW SNOW LOOKS POSSIBLE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 210 PM MDT FRI MAY 8 2015
...ACTIVE WEATHER PATTERN IN PLACE OVER THE WEEKEND...
SATURDAY NIGHT THROUGH SUNDAY...MODELS INDICATE THAT THE UPPER LOW
WILL BE LOCATED OVER SOUTH-CENTRAL CO SAT EVENING...AND WILL QUICKLY
EJECT TO THE NE TO NEBRASKA SUN MORNING...THEN SOUTH DAKOTA SUN
NIGHT. ACTIVITY SHOULD BE SLIGHTLY SUBDUED ACROSS THE SE PLAINS SAT
NIGHT AS THE LOW MOVES NE...BUT WRAPAROUND WILL START AFFECTING THE
PALMER DVD AND RAMPART RANGE. CATEGORICAL SHOWERS ARE FORECAST OVER
MONUMENT HILL SAT EVE...WITH DROPPING TEMPS SWITCHING THE PCPN OVER
TO SNOW OVERNIGHT. UP TO 2 INCHES OF NEW SNOW WILL BE POSSIBLE FOR
MONUMENT HILL BY SUN MORNING...BUT HIGHER AMOUNTS WILL BE POSSIBLE
FOR TELLER COUNTY AND ESPECIALLY PIKES PEAK SO THE PEAK HAS BEEN
INCLUDED IN THE WINTER STORM WATCH. AS THE SYSTEM CONTINUES PULLING
AWAY LATE SUN...SHOWER AND STORM ACTIVITY IS EXPECTED TO DIMINISH.
LOOK FOR MAX TEMPS IN THE 50S TO AROUND 60F FOR MOST AREAS ON
SUN...WITH OVERNIGHT MIN TEMPS IN THE LOWER TO MID 30S.
MONDAY THROUGH WEDNESDAY...TEMPORARY RIDGING OVER THE STATE MON WILL
GIVE WAY TO A SW FLOW ALOFT ON TUE. RESIDUAL MOISTURE IS EXPECTED TO
SPARK MORE SHOWER AND STORM ACTIVITY MON AFTN AND EVE...THEN AS THE
SW FLOW SETTLES IN FOR TUE A PLUME OF GULF MOISTURE WILL BE DRAWN UP
ACROSS NM AND INTO COLORADO. THE BEST WINDOW FOR STORM ACTIVITY WILL
OCCUR TUE AND WED...WITH THE EMPHASIS ON TUE. STORMS WILL INITIATE
OVER THE HIGHER TERRAIN BOTH DAYS BY LATE MORNING...THEN TRACK E-NE
OVER THE ADJACENT PLAINS THROUGH THE AFTN AND EVE. LOOK FOR MAX
TEMPS TO WARM MON THROUGH WED WITH 60S ON MON TO MID TO UPPER 70S BY
WED.
THURSDAY AND FRIDAY...SW FLOW ALOFT REMAINS IN PLACE THROUGH THE
REST OF THE WORK WEEK...WITH MAX TEMPS IN THE 70S CONTINUING. THE
PLUME OF GULF MOISTURE IS FORECAST TO SLIDE TO THE EAST OUT OF THE
REGION...SO STORM ACTIVITY WILL BECOME MORE ISOLATED AND DIURNAL IN
NATURE AND TIED MORE TO THE HIGHER TERRAIN. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1104 PM MDT FRI MAY 8 2015
A MAJOR SPRING STORM WILL APPROACH THE FOUR CORNERS REGION TONIGHT
AND THEN MOVE THROUGH SE CO ON SATURDAY. THIS LOW PRESSURE SYSTEM
WILL BRING SIGNIFICANT WEATHER TO THE AREA...ESPECIALLY OVER THE
MOUNTAINS AND EASTERN PLAINS. THE SAN LUIS VALLEY WILL BE SOMEWHAT
SHELTERED BUT COULD STILL SEE OCCASIONAL RA-SN OR TS. STRONG
UPSLOPE FLOW OVER THE PLAINS WILL LEAD TO CONTINUED LIFR-MVFR FOR
THE KCOS AND KPUB TERMINALS AND SURROUNDING AREAS. LIFR-IFR WILL
BE MOST LIKELY IN THE 09Z-15Z TIME PERIOD BUT COULD OCCUR IN
PERIODS THROUGH THE TAF CYCLE. ROUNDS OF PRECIP INCLUDING TSRA
WILL BE LIKELY THROUGH THE DAY ON SATURDAY. TS COULD PRODUCE
SIGNIFICANT HAIL AND/OR GRAUPEL IN ADDITION TO STRONG WINDS AND
HEAVY RAIN. SIGNIFICANT SVR WEATHER WILL BE POSSIBLE OVER THE FAR
ERN PLAINS...NR THE KS BORDER...INCLUDING TORNADOES. AS THIS
SYSTEM MOVES TO OUR NE LATE SATURDAY...A STRONG COLD FRONT WILL
DROP SNOW LEVELS BELOW 6000 FEET BY SUN MORNING. ACCUMULATING SNOW
WILL BE POSSIBLE AT KCOS AFTER 06Z SUN THROUGH AROUND 18Z
SUN...THOUGH AT THIS TIME IT DOES NOT LOOK SIGNIFICANT AND THE
GREATER THREAT WILL CONTINUE TO BE SIGNIFICANT HAIL AND TB. THE
NEXT 36 HOURS OR SO WILL BE VERY HAZARDOUS OVER THE AREA FOR
GENERAL AVIATION. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY
NIGHT FOR COZ058-060-061-082.
&&
$$
UPDATE...ROSE
SHORT TERM...MOORE
LONG TERM...PETERSEN
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
1055 PM EDT SUN MAY 10 2015
.SYNOPSIS...
COLD FRONT OVER NORTHERN NEW YORK AND NEW ENGLAND
WILL BRING SCATTERED SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS
OVERNIGHT MAINLY FROM THE CAPITAL REGION AND BERKSHIRES NORTHWARD.
MORE WIDESPREAD CHANCES OF SHOWERS AND THUNDERSTORMS WILL OCCUR
MONDAY INTO TUESDAY BEFORE THE FRONT MOVES THROUGH. VERY WARM
TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
THE COLD FRONTAL PASSAGE WILL USHER IN MUCH COOLER AND DRIER AIR BY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1055 PM EDT...THE COLD FRONT HAS DRIFTED S/SE INTO THE
ADIRONDACKS...NRN NEW ENGLAND...AND ACROSS LAKE ONTARIO. A SFC
TROUGH MOVING ALONG THE FRONT CONTINUES TO FOCUS A BATCH OF
SHOWERS AND SOME ISOLD THUNDERSTORMS. WE LOWERED THE THUNDERSTORM
CHANCES TO SLIGHT CHC THE REST OF THE NIGHT. THE SHOWERS AND ISOLD
STORMS WILL BE MAINLY FROM THE NRN CATSKILLS...CAPITAL
REGION...AND NRN BERKSHIRES NORTHWARD. A FEW THUNDERSTORMS
CONTINUE TO MOVE ACROSS SRN VT THIS EVENING. THE TREND SHOULD BE
FOR THE CONVECTION TO WANE WITH THE LOSS OF THE DAYTIME HEATING
AND THE SPC RAP MESOANALYSIS PAGE SHOWING GENERALLY LESS THAN 250
J/KG OF SBCAPE. THE BEST MUCAPES ARE OVER WRN NEW ENGLAND /AROUND 500
J/KG/. THE 00Z KALY SOUNDING HAS A PWAT OF 1.45". SOME LOCALLY
HEAVY DOWNPOURS ARE POSSIBLE.
PATCHY FOG WAS ADDED TO THE SE CATSKILLS...MID HUDSON VALLEY AND
NW CT CORRIDOR WHERE IT IS MOSTLY CLEAR AND THE WINDS WILL GO
LIGHT TO CALM. VERY HUMID CONDITIONS WILL CONTINUE OVERNIGHT WITH
SFC DEWPTS IN THE M50S TO M60S. IT WILL BE A MUGGY NIGHT WITH LOWS
IN THE LOWER TO MID 60S IN MANY LOCATIONS...AND SOME U50S OVER THE
SRN DACKS...AND ERN CATSKILLS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
BY MONDAY THE FRONTAL BOUNDARY SHOULD BE STALLED ACROSS THE
CENTRAL PORTION OF OUR FA WITH A LOW PRESSURE SYSTEM MOVING
EASTWARD ALONG IT. THIS SHOULD BRING THE FIRST WIDESPREAD RAINFALL
TO OUR REGION IN NEARLY TWO WEEKS. THERE ARE SEVERAL KEY
INGREDIENTS IN PLACE WHICH SHOULD PROMOTE THUNDERSTORM ACTIVITY IN
ADDITION TO THE AFOREMENTIONED COLD FRONT. THERE WILL BE A STRONG
THETA E RIDGE ACROSS THE REGION ESPECIALLY DURING THE AFTERNOON
HOURS WHICH COUPLED WITH SB CAPES OF 500-1500 J/KG...PWATS 1.25
TO 1.75 INCHES AND 0-3 KM HELICITY OF 100-200 M2/S2 SHOULD ALL
FOCUS THE CONVECTION. HIGHS ON MONDAY SHOULD BE IN THE UPPER 60S
TO LOWER 80S.
MONDAY NIGHT AND TUESDAY WILL CONTINUE TO BE VERY HUMID WITH HIGH
PWAT VALUES AT LEAST THROUGH THE FIRST HALF OF TUESDAY. THE
FRONTAL BOUNDARY WILL BE MOVING THROUGH THE EASTERN GREAT LAKES
EARLY TUESDAY MORNING AND THROUGH OUR FA DURING THE MID DAY HOURS
TO EARLY AFTERNOON AS LOW PRESSURE MOVES ACROSS SOUTHERN CANADA.
SO THE BEST CHANCES FOR CONVECTION LOOK TO BE LATE MONDAY NIGHT
THROUGH EARLY AFTERNOON ON TUESDAY. EXPECT LOWS MONDAY NIGHT TO BE
IN THE UPPER 50S TO MID 60S WITH HIGHS ON TUESDAY IN UPPER 60S TO
LOWER 80S WITH TEMPS FALLING LATE IN THE DAY AS COLD AIR ADVECTION
TAKES HOLD.
TUESDAY NIGHT INTO WEDNESDAY...THE COLD FRONT WILL BE WELL EAST
OF THE REGION BY TUESDAY EVENING. HOWEVER...THE UPPER LEVEL
TROUGH AXIS AND AN ASSOCIATED SFC TROUGH WILL BE MOVING ACROSS
MOST OF THE FCST AREA TUE NIGHT INTO WED WITH A SLIGHT TO LOW CHC
OF SHOWERS...ESPECIALLY FROM THE CAPITAL REGION...NRN
CATSKILLS...AND BERKSHIRES NORTHWARD. IT WILL BE BRISK AND MUCH
COOLER TUESDAY NIGHT AND WEDNESDAY WITH LOWS TUESDAY NIGHT IN THE
MID 40S TO MID 50S AND HIGHS ON WEDNESDAY IN THE MID 50S TO MID
60S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE FIRST HALF OF THE PERIOD WILL BE MARKED BY CLEARING SKIES AS
HIGH PRESSURE SETTLES IN FROM THE WEST. THE POSSIBILITY OF A WEAK
FRONTAL BOUNDARY DEVELOPING SOUTH AND WEST OF OUR FORECAST AREA MAY
BRING THE ONLY CHANCE OF SHOWERS DURING THIS PERIOD...WELL SOUTH OF
THE CAPITAL REGION ON SATURDAY...BUT SUNSHINE WILL NOT BE ABSENT.
SUNDAY WILL BE CLOUDIER AND MORE HUMID...BUT PRECIPITABLE
MOISTURE WILL BE GREATLY LIMITED.
TEMPERATURES WILL ALSO AVERAGE MUCH CLOSER TO NORMAL THAN IN RECENT
DAYS...WITH HIGHS FROM THE MID 50S TO UPPER 60S THURSDAY SLOWLY
MODERATING ABOUT ANOTHER 10 DEGREES THROUGH SUNDAY. LOWS WEDNESDAY
NIGHT RANGING FROM THE MID 30S TO MID 40S WILL ALSO MODERATE ABOUT
ANOTHER 10 DEGREES THROUGH SATURDAY NIGHT. NORMAL HIGHS AT ALBANY
ARE AROUND 70 DEGREES...WITH NORMAL LOWS IN THE UPPER 40S.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
A COLD FRONT AND LOW PRESSURE SYSTEM MOVING ALONG WILL BRING SOME
SCATTERED SHOWERS AND THUNDERSTORMS TO PARTS OF UPSTATE NEW YORK
AND NEW ENGLAND TONIGHT...ESPECIALLY FROM THE MOHAWK VALLEY
NORTHWARD INCLUDING THE NORTHERN BERKSHIRES. THE BOUNDARY WILL
SLOWLY LIFT BACK NORTH TOMORROW. HOWEVER...ANOTHER DISTURBANCE
MOVING ALONG IT MAY BRING MORE SHOWERS AND THUNDERSTORMS LATE
TOMORROW AFTERNOON INTO THE EVENING.
A PREFRONTAL SFC TROUGH CONTINUES TO MOVE ALONG THE COLD FRONT
THIS EVENING. A BATCH OF RAIN WITH EMBEDDED THUNDERSTORMS IS
MOVING INTO THE MOHAWK VALLEY. THIS AREA OF RAIN AND SCT
THUNDERSTORMS SHOULD IMPACT KGFL/KALB/KPSF IF IT HOLDS TOGETHER
BETWEEN 02Z-06Z. OTHER ISOLD THUNDERSTORMS ARE MOVING THROUGH THE
BERKSHIRES AT 2330Z...AND A 2-HR TEMPO TEMPO WAS USED AT KPSF.
EXPECT VFR/MVFR IN THE SHOWERS AND THUNDERSTORMS PRIOR 06Z. KPOU
WILL BE VFR...UNTIL LOW STRATUS AND SOME MIST FORM TOWARDS
06Z/MON. EXPECT CONDITIONS TO LOWER TO MVFR/IFR LEVELS BTWN 06Z-
12Z IN THE HUMID AIR MASS. EXPECTING LOW STRATUS TO IMPACT ALL THE
TAF SITES...WITH A PERIOD OF IFR CONDITIONS BTWN 09Z-13Z/MON. WE
ARE MORE CONFIDENT ON THE CIGS THAN THE VSBYS...BUT TO BE
CONSISTENT CIGS OF 600-800 FT AGL WERE FORECASTED WITH VSBYS
AROUND 2SM. LOCATIONS THAT RECEIVE SOME RAINFALL THIS EVENING
WILL HAVE THE GREATEST THREAT FOR IFR. TEMPO GROUPS MAY FINE TUNE
THE IFR CONDITIONS LATER.
CONDITIONS SHOULD BECOME VFR ONCE AGAIN AFTER 13Z-15Z/MON AT ALL
THE TAF SITES AS THE MVFR/IFR LOW STRATUS AND MIST BURNS OFF.
EXPECTING VFR CONDITIONS UNTIL THE MID TO LATE PM WHEN ANOTHER
ROUND OF SHOWERS AND THUNDERSTORMS WILL IMPACT KGFL/KALB/KPSF/KPOU
BTWN 20Z/MON TO 00Z/TUE. VCSH GROUPS WERE USED AT THIS POINT WITH
CLOUD BASES BTWN 4-5 KFT AGL.
THE WINDS WILL BE FROM SOUTH TO SOUTHWEST AT 4-8 KTS TONIGHT...AND
WILL BECOME LIGHT TO CALM SHORTLY AFTER MIDNIGHT. SOUTH TO
SOUTHWEST WINDS WILL INCREASE FROM 6-11 KTS LATER TOMORROW
MORNING INTO THE AFTERNOON.
OUTLOOK...
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
WEDNESDAY NIGHT-FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A LOW PRESSURE SYSTEM AND A FRONTAL BOUNDARY WILL BRING CHANCES OF
SHOWERS AND THUNDERSTORMS TONIGHT MAINLY FROM THE CAPITAL REGION
AND BERKSHIRES NORTHWARD. MORE WIDESPREAD CHANCES OF SHOWERS AND
THUNDERSTORMS WILL OCCUR MONDAY INTO TUESDAY. VERY WARM
TEMPERATURES WILL REMAIN IN PLACE WITH INCREASING HUMIDITY LEVELS.
THE COLD FRONT WILL USHER IN MUCH COOLER AND DRIER AIR BY
WEDNESDAY.
RELATIVE HUMIDITY VALUES WILL RECOVER TO 80 TO 100 PERCENT
TONIGHT...DROP TO 45 TO 60 PERCENT ON MONDAY...RECOVER TO 80 TO
100 PERCENT MONDAY NIGHT AND FALL TO 35 TO 50 PERCENT ON TUESDAY.
WINDS TONIGHT WILL BE SOUTH TO SOUTHEAST AT AROUND 5
MPH...SOUTHEAST AT 5 TO 10 MPH ON MONDAY...SOUTH TO SOUTHEAST AT 5
MPH MONDAY NIGHT AND SOUTHWEST AT 10 TO 20 MPH ON TUESDAY.
&&
.HYDROLOGY...
THERE WILL BE GRADUALLY INCREASING CHANCES FOR SHOWERS AND
THUNDERSTORMS SPREADING SOUTH AND EAST FROM THIS AFTERNOON THROUGH
TUESDAY...AS A LOW PRESSURE SYSTEM AND FRONTAL BOUNDARY APPROACH
AND EVENTUALLY MOVE THROUGH.
IT HAS BEEN VERY DRY ACROSS THE HYDRO SERVICE AREA IN RECENT WEEKS.
THERE IS A CHANCE OF LOCALLY HEAVY RAINFALL ASSOCIATED WITH
THUNDERSTORMS...ALTHOUGH RAINFALL WILL BE BENEFICIAL IN MOST PLACES
DUE TO VERY DRY ANTECEDENT GROUND CONDITIONS. BASIN-AVERAGE RAINFALL
WILL NOT BE UNIFORM DUE TO THE CONVECTIVE NATURE OF THE
PRECIPITATION...WITH SOME SPOTS RECEIVING AN INCH OR MORE THROUGH
TUESDAY.
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...JPV/WASULA
NEAR TERM...WASULA
SHORT TERM...11
LONG TERM...ELH
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1011 AM EDT SAT MAY 9 2015
.DISCUSSION...
...MODERATE RIP CURRENT RISK...
TODAY-TONIGHT... ATLANTIC HIGH PRESSURE RIDGE HAS CONTINUED TO NUDGE
BACK NORTHWARD IN THE WAKE OF ANA. WITH A SEPARATE HIGH PRESSURE
CELL IN THE GULF...THE LOCAL AREA WAS IN A WEAK COL. THE RESULTING
LIGHT WIND FLOW PATTERN WILL ALLOW FOR QUICKER INLAND MOTION OF THE
EAST COAST SEA BREEZE.
A COLLISION OF THE WEST/EAST COAST BOUNDARIES WILL OCCUR OVER THE
INTERIOR DURING THE EARLY EVENING. THE MAIN QUESTION THOUGH IS THE
AMOUNT OF MOISTURE AVAILABLE FOR CONVECTION. MORNING CANAVERAL
SOUNDING AT FIRST GLANCE SHOWED SOME PROSPECT...WITH A PRECIPITABLE
WATER VALUE AROUND 1.5 INCHES. BUT WITH NORTHWARD LIFTING OF
SYNOPTIC FEATURES...SOUNDINGS AT TAMPA/MIAMI WILL ACTUALLY BECOME
MORE REPRESENTATIVE OF OUR AFTERNOON AIR MASS...AND THEY ARE DRIER.
WITH THE BOUNDARY COLLISION OCCURRING QUITE LATE AND IN A LIMITED
MOISTURE ENVIRONMENT...THE CURRENT FORECAST WHICH HAS SLIGHT SHOWER
CHANCES OVER THE INTERIOR...LOOKS OKAY. THE HRRR MODEL IS GENERALLY
SUPPORTIVE...SO WILL NOT MAKE ANY CHANGES.
&&
.AVIATION...MAINLY VFR. ANY INTERIOR SHOWERS THAT DEVELOP LATE IN
THE DAY WOULD BE BRIEF.
&&
.MARINE...
TODAY-TONIGHT...THE LIFTING OF ANA NORTHWARD IS ALLOWING THE
ATLANTIC HIGH PRESSURE RIDGE TO BUILD BACK TOWARDS THE WATERS. A
LIGHT SOUTH/SOUTHWEST GRADIENT WIND THIS MORNING WILL BECOME
DISTORTED BY THE SEA BREEZE CIRCULATION THIS AFTERNOON WITH MAINLY A
SOUTHEAST WIND SETTING UP ACROSS THE ATLANTIC WATERS WITH SPEEDS 10
KNOTS OR LESS...EXCEPT 10-13 KNOTS NEAR THE COAST WITH THE SEA BREEZE.
NORTHEAST SWELLS WILL KEEP SEAS SLIGHT ELEVATED DESPITE THE OVERALL
RATHER BENIGN GRADIENT WIND SPEEDS.
THEN AS THE RIDGE AXIS BUILDS INTO THE WATERS TONIGHT THE WIND FLOW
WILL BECOME SOUTH AT ABOUT 10-13 KNOTS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION...RESENT
NWS TAMPA BAY RUSKIN FL
440 AM EDT SAT MAY 9 2015
.SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOW A DEEP
MID/UPPER LEVEL FLOW PATTERN FROM THE NW/N BETWEEN THE UPPER LEVEL
REFLECTION OF TROPICAL STORM ANA...AND A RIDGE AXIS OVER THE
WESTERN/CENTRAL GULF OF MEXICO. GENERALLY SPEAKING THE MID/UPPER
LEVELS ARE QUITE DRY WITH WEAK LARGE SCALE SUBSIDENCE IN PLAY. THESE
CONDITIONS WILL HELP KEEP OUR FORECAST DRY TODAY. ELSEWHERE ACROSS
THE CONUS WE FIND A LARGE AND POTENT UPPER LOW EJECTING EASTWARD
FROM THE FOUR CORNERS REGION TOWARD THE CENTRAL/SOUTHERN PLAINS.
SEVERAL ROUNDS OF POTENTIALLY SEVERE WEATHER ARE EXPECTED THROUGH
THE WEEKEND ASSOCIATED WITH THE EVOLUTION OF THIS
SYSTEM...HOWEVER...THIS WILL NOT BE A CONCERN FOR OUR FORECAST AS WE
REMAIN WELL REMOVED FROM ITS INCLEMENT INFLUENCE.
AT THE SURFACE...A WEAK PRESSURE GRADIENT IS IN PLAY BETWEEN
TROPICAL STORM ANA SPINNING NEAR THE CAROLINA COAST...AND HIGH
PRESSURE ACROSS THE CENTRAL GULF OF MEXICO. TEMPERATURES ARE
SEASONABLE EARLY THIS MORNING WITH MOST LOCATIONS REPORTING IN THE
60S.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY... A SEASONABLE EARLY/MID MAY DAY ON TAP FOR WEST-CENTRAL AND
SOUTHWEST FLORIDA. THE GRADIENT WILL REMAIN WEAK THROUGH THE DAY AND
PROMOTE DEFINED SEA-BREEZE DEVELOPMENT WITHIN A FEW HOURS OF THE
ONSET OF TERRESTRIAL DIABATIC HEATING. HIRES GUIDANCE MEMBERS ARE
ADVERTISING A 10-15 MPH BREEZE DEVELOPING AT THE BEACHES BY
17Z...AND SPREADING INLAND THROUGH THE REMAINDER OF THE AFTERNOON.
TEMPERATURES WILL REACH THE UPPER 80S TO LOWER 90S FOR MOST
LOCATIONS...WITH SLIGHTLY COOLER READINGS AT THE IMMEDIATE COAST
WITH THE ONSHORE AFTERNOON FLOW OFF THE SOMEWHAT COOLER SHELF
WATERS. DESPITE THE DEFINED SEA-BREEZE AND ASSOCIATED FOCUS ZONE FOR
ASCENT...DO NOT ANTICIPATE MUCH IN THE WAY OF THUNDERSTORM
DEVELOPMENT...AND HAVE LEFT MENTION OUT OF THE FORECAST FOR ALL
AREAS TODAY. CONVECTION ALLOWING MODEL SUITE IS ALMOST COMPLETELY
DRY AND BASED ON THE FAIRLY HOSTILE ENVIRONMENT ALOFT FOR DEEP
CONVECTION...SEE LITTLE REASON TO DISAGREE. CONVECTIVE COLUMNS WILL
BE QUICKLY INGESTING SUB 320K THETAE AIR AS THEY DEVELOP AND THIS
SHOULD SIGNIFICANTLY LIMIT THE POTENTIAL FOR GROWTH. CAN NOT RULE OUT
A BRIEF SHOWERS OVER POLK/HIGHLANDS/SUMTER COUNTIES AFTER 19-
20Z...HOWEVER FEEL COVERAGE (IF ANY) WILL BE UNDER 10%.
TONIGHT...QUIET CONDITIONS CONTINUE INTO THE OVERNIGHT HOURS WITH
THE SEA-BREEZE DECAYING WITHIN A FEW HOURS AFTER SUNSET...FOLLOWED
BY LIGHT AND VARIABLE FLOW / OFFSHORE FLOW DEVELOPING NEAR THE
COAST. EARLY MORNING LOW TEMPERATURES AGAIN MAINLY IN THE
60S...EXPECT LOWER 70S ACROSS SOUTHERN PINELLAS COUNTY AND ALONG THE
IMMEDIATE COAST OF MANATEE/SARASOTA/CHARLOTTE/LEE COUNTIES.
SUNDAY...MINOR CHANGES BEGIN TO EVOLVE TO THE SYNOPTIC PATTERN BY
THE END OF THE WEEKEND. TROPICAL STORM ANA REMAINS WELL TO OUR NORTH
AS ATLANTIC HIGH PRESSURE BEGINS TO RIDGE BACK WESTWARD OVER THE
FLORIDA PENINSULA. WITH THE RIDGE AXIS FORECAST TO LIE THROUGH THE
CENTER OF THE STATE...THIS WILL FAVOR A SLIGHTLY BETTER CHANCE FOR AN
AFTERNOON STORM OR TWO SOUTH OF THE I-4 CORRIDOR (AND MAINLY INLAND
AWAY FROM THE COAST). THE LIGHT SYNOPTIC SE FLOW AROUND THE RIDGE
WILL HELP FOCUS THE LIFT ALONG THE WEST COAST SEABREEZE OVER THE
SOUTHERN ZONES. OVERALL THE ENVIRONMENT ALOFT IS STILL NOT THAT
FAVORABLE...HOWEVER THE ENHANCED LIFT SUGGESTS GIVING THE STORMS THE
BENEFIT OF THE DOUBT AND ALLOWING LOW END CHANCE POPS DURING THE
LATE AFTERNOON/EARLY EVENING. AS MENTIONED ABOVE...THE SEA-BREEZE
SHOULD MAKE SOME PROGRESS INLAND AND KEEP THE BEST STORM CHANCES
AWAY FROM THE BEACHES. FURTHER NORTH...THE SEA-BREEZE SHOULD MOVE
QUICKLY INLAND...AND LITTLE IS DIFFERENT FROM TODAY IN TERMS OF
STORM SETUP. WILL AGAIN LEAVE POPS OUT OF THE FORECAST FOR TAMPA BAY
AND THE NATURE COAST.
HAVE A GREAT WEEKEND EVERYONE!
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)... ALOFT - A CLOSED LOW OVER
THE NORTHERN PLAINS TRACKS EAST...SWEEPING AWAY THE REMNANTS OF
ANA...AND BECOMES AN OPEN TROUGH OVER EASTERN CANADA BY FRI.
MEANWHILE AN UPPER RIDGE BUILDS OVER THE GULF THEN RIDGES NORTHWARD
AS IT SLIDES EAST...REACHING FL BY THE END OF THE WEEK. AT THE
SURFACE ATLANTIC HIGH PRESSURE RIDGES ACROSS FL INTO THE
GULF...GETTING REINFORCED DURING LATE WEEK BY HIGH PRESSURE MOVING
ACROSS THE CENTRAL THEN EASTERN CONUS...BRIDGING A FRONTAL BOUNDARY
THAT SLOWLY SETTLES IN OVER THE GULF COASTAL AND SOUTHEASTERN
STATES.
A PREVAILING LOW LEVEL SOUTHEASTERLY FOR MUCH OF THE PERIOD WILL
PROVIDE AMPLE MOISTURE...MODEL PWAT VALUES RANGE IN THE 1.3 TO 1.9
INCH RANGE...AND WILL ALSO BE LIGHT ENOUGH TO PERMIT AFTERNOON SEA
BREEZES...RESULTING IN SCATTERED THUNDERSTORMS. TEMPERATURES
INITIALLY BEGIN ABOVE NORMAL...LOWS CONTINUE TO RUN ABOVE THOUGH THE
WEEK BUT HIGHS TREND DOWN SOME DUE TO RAINFALL AND ASSOCIATED CLOUD
COVER.
&&
AVIATION... VFR CONDITIONS ARE FORECAST TO CONTINUE THROUGH THE
DURATION OF THE TAF PERIOD. MOST TAF SITES WILL SEE AN INCREASE
IN WESTERLY WINDS THIS AFTERNOON/EARLY EVENING WITH SEA-BREEZE
DEVELOPMENT...WITH A SIMILAR SCENARIO FOR SUNDAY AFTERNOON.
NO THUNDERSTORM ACTIVITY IS EXPECTED TODAY...BUT SMALL CHANCES
FOR A LATE DAY STORM EXIST ON SUNDAY FOR KLAL...KPGD...KFMY AND
KRSW.
&&
.MARINE... A WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE REGION
BETWEEN TROPICAL STORM ANA LOCATED NEAR THE CAROLINA COAST...AND
HIGH PRESSURE OVER THE CENTRAL GULF OF MEXICO. WINDS ARE FORECAST TO
GENERALLY REMAIN BELOW 15 KNOTS...ALTHOUGH A FEW GUSTS NEAR 15 KNOTS
WILL BE POSSIBLE NEAR THE COAST EACH AFTERNOON WITH THE DEVELOPMENT
OF THE SEA-BREEZE. NO THUNDERSTORM ACTIVITY IS ANTICIPATED OVER THE
COASTAL WATERS TODAY OR SUNDAY. SLIGHTLY BETTER CHANCES FOR A LATE
DAY STORMS NEAR THE COAST ENTER THE FORECAST FOR LATER MONDAY
AFTERNOON.
&&
.FIRE WEATHER... A WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE
REGION BETWEEN TROPICAL STORM ANA NEAR THE CAROLINA COAST...AND HIGH
PRESSURE OVER THE CENTRAL/EASTERN GULF OF MEXICO. WINDS WILL BE
DOMINATED BY THE DEVELOPMENT AND INLAND PROPAGATION OF THE DAILY SEA
BREEZE THROUGH THE EARLY PORTION OF NEXT WEEK. RAIN CHANCES WILL BE
VERY LOW TODAY...WITH WIDELY SCATTERED STORMS EXPECTED INLAND DURING
SUNDAY...AND FINALLY SCATTERED STORMS FOR MOST AREAS BY MONDAY
AFTERNOON. EXPECTING MARGINALLY CRITICAL RELATIVE HUMIDITY VALUES
AWAY FROM THE COAST FOR A FEW HOURS THIS AFTERNOON...AND AGAIN FOR
SUNDAY AFTERNOON. EXTENDED DURATIONS OF THESE LOWER RELATIVE
HUMIDITY VALUES ARE NOT EXPECTED AND WINDS ARE EXPECTED TO GENERALLY
REMAIN BELOW CRITICAL LEVELS. THEREFORE...NO RED FLAG CONDITIONS ARE
ANTICIPATED THROUGH THE EARLY PORTION OF NEXT WEEK.
FOG IMPACT...NO SIGNIFICANT FOG IS EXPECTED THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 72 89 72 / 0 0 10 10
FMY 90 69 91 72 / 0 0 20 10
GIF 91 70 92 71 / 10 10 30 10
SRQ 85 70 86 71 / 0 0 10 10
BKV 90 65 90 65 / 0 0 10 10
SPG 87 74 87 75 / 0 0 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
100 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT SUN MAY 10 2015
WILL UPDATE THE FORECAST LATE THIS MORNING FOR SOME ADJUSTMENT TO
CHANCES OF SHOWERS AND THUNDERSTORMS REST OF THE DAY...AS
CONVECTION AS BEEN MORE WIDELY SCATTERED THIS MORNING. ALSO HAVE
LINGERING FOG OVER NORTHERN COUNTIES NORTH OF WARM FRONT AND
LOCALLY DENSE THIS MORNING. THE WARM FRONT CURRENTLY WAS SLOWLY
LIFTING NORTH AND WAS SOUTH OF MACOMB AND PEORIA AND JUST PASSED
NORTH OF BLOOMINGTON AIRPORT A HALF HOUR AGO. THE FRONT WILL
SLOWLY PUSH NORTH ACROSS NORTHERN COUNTIES THIS AFTERNOON AND THIS
AREA WILL HAVE BEST CHANCES OF DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS IN WARM/HUMID AIRMASS. ANOTHER AREA OF CONVECTION
WILL SPREAD NE ACROSS CENTRAL IL DURING THE EVENING. SPC CONTINUES
SLIGHT RISK OF SEVERE STORMS LATER THIS AFTERNOON AND EVENING
ACROSS MUCH OF CENTRAL IL ESPECIALLY FROM I-57 WEST WHERE CAPES
GET TO 1500-2500 J/KG BY 00Z/7 PM CENTRAL AND WESTERN CWA AND BULK
SHEAR TO 25-35 KTS WESTERN CWA BY SUNSET. HIGHS TO RANGE FROM LOW
TO MID 70S FAR NORTHERN 3 COUNTIES OF KNOX...STARK AND MARSHALL...
TO THE UPPER 70S AND LOWER 80S FROM PEORIA SOUTH.
&&
.SHORT TERM...(TODAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
SOUTHWESTERLY UPPER-LEVEL FLOW CONTINUES TO BRING COPIOUS AMOUNTS OF
MOISTURE NORTHWARD INTO THE MIDWEST...AS EVIDENCED BY TONGUE OF
10-15C 850MB DEWPOINTS EXTENDING FROM TEXAS N/NE INTO THE
SOUTHERN GREAT LAKES. STATIONARY FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS THIS MORNING AND HAS BEEN THE FOCUS FOR
WIDELY SCATTERED SHOWERS ACROSS THE AREA. THE BULK OF THE
CONVECTION HAS BEEN FURTHER SOUTHWEST ACROSS OKLAHOMA/ARKANSAS IN
CONJUNCTION WITH A SHORT-WAVE TROUGH EMBEDDED WITHIN THE
SOUTHWESTERLY FLOW PATTERN. MODELS HAVE BEEN CONSISTENTLY LIFTING
THIS ACTIVITY NORTHWARD INTO ILLINOIS THIS MORNING...HOWEVER
SATELLITE/RADAR TRENDS DO NOT SUPPORT THIS. LATEST RADAR MOSAIC
SHOWS ONLY SCATTERED SHOWERS ACROSS CENTRAL/SOUTHERN MISSOURI.
GIVEN THIS TREND...HAVE OPTED TO LOWER POPS INTO THE 40-50 PERCENT
RANGE THROUGH MIDDAY. AFTER THE INITIAL WAVE OF PRECIP THIS
MORNING...MODEL SOLUTIONS VARY GREATLY CONCERNING THE
AFTERNOON/EVENING STORM POTENTIAL. 00Z NAM SHOWS A MESOSCALE
CONVECTIVE VORTEX (MCV) EJECTING NORTHEASTWARD FROM THE OKLAHOMA
STORM COMPLEX...WHICH TRIGGERS NUMEROUS SHOWERS AND THUNDERSTORMS
ACROSS THE WESTERN HALF OF THE KILX CWA DURING THE AFTERNOON.
BASED ON CURRENT RADAR TRENDS...AM QUITE SKEPTICAL OF THIS
SOLUTION. MEANWHILE...THE HRRR SUGGESTS THAT AFTER A ROUND OF
MORNING SHOWERS, A LULL IN PRECIP CHANCES WILL BE SEEN UNTIL LATE
AFTERNOON/EARLY EVENING WHEN A LINE OF STORMS APPROACHES FROM THE
SOUTHWEST. THIS MAY HAVE TOO MUCH NAM INFLUENCE IN IT...SO AM NOT
EXCITED ABOUT THIS SOLUTION EITHER. PREFER THE SLOWER
GFS/SREF...WHICH BOTH SHOW MORNING SHOWERS FOLLOWED BY A MOSTLY
DRY AFTERNOON. BOTH MODELS SUGGEST STRONG/SEVERE CONVECTION WILL
DEVELOP FURTHER WEST ALONG AN ADVANCING COLD FRONT ACROSS THE
CENTRAL PLAINS...WITH ANOTHER LINE OF STORMS FORMING FURTHER EAST
ACROSS MISSOURI IN THE AFTERNOON, THEN TRACKING INTO ILLINOIS
DURING THE EVENING. FOLLOWING THIS SOLUTION YIELDS CHANCE POPS
THROUGHOUT THE DAY...WITH RAIN CHANCES RAMPING UP TONIGHT. DESPITE
SLOW PASSAGE OF A WARM FRONT...TODAY WILL BE A MOSTLY CLOUDY AND
HUMID DAY. DUE TO THE EXTENSIVE CLOUD COVER...HAVE LOWERED HIGH
TEMPERATURES INTO THE 70S ACROSS ALL BUT THE FAR SE WHERE READINGS
WILL TOP THE 80 DEGREE MARK.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 329 AM CDT SUN MAY 10 2015
LINE OF THUNDERSTORMS WILL PROGRESS INTO CENTRAL ILLINOIS THIS
EVENING...POTENTIALLY PRODUCING STRONG WINDS AND HAIL. STORMS WILL
TEND TO WEAKEN AS THEY APPROACH THE I-57 CORRIDOR BY LATE EVENING
INTO THE OVERNIGHT HOURS...SO SEVERE THREAT REMAINS LOWEST ACROSS
THE E/SE CWA. WILL CARRY CATEGORICAL POPS ACROSS ALL LOCATIONS
ALONG/WEST OF I-57 ACCORDINGLY. AS SURFACE COLD FRONT CROSSES THE
MISSISSIPPI RIVER AND INTERACTS WITH THE VERY MOIST AIRMASS IN
PLACE...SHOWERS AND THUNDERSTORMS WILL BE WIDESPREAD ACROSS THE AREA
MONDAY MORNING. MODELS ARE IN GOOD AGREEMENT CONCERNING
FROPA...WITH CONSENSUS TAKING THE COLD FRONT INTO INDIANA DURING THE
AFTERNOON. HAVE THEREFORE LOWERED POPS ACROSS THE WEST AND REMOVED
POPS ENTIRELY WEST OF THE ILLINOIS RIVER FOR THE AFTERNOON.
ONCE THE FRONT PASSES...A COOLER/DRIER AIRMASS WILL SETTLE INTO THE
REGION FOR THE MIDDLE OF THE WEEK. HIGH TEMPERATURES WILL DROP 5-10
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR INTO THE LOWER TO MIDDLE
60S FOR TUESDAY AND WEDNESDAY. AFTER THAT...UPPER HEIGHTS WILL
BEGIN TO RISE AS SOUTHWESTERLY FLOW ONCE AGAIN ESTABLISHES ITSELF
ACROSS THE MIDWEST. THIS WILL RESULT IN WARMING TEMPS AND
INCREASING RAIN CHANCES BY THE END OF THE WEEK. CONSIDERABLE MODEL
SPREAD EXISTS ON TIMING OF FIRST EMBEDDED SHORT-WAVE WITHIN THE
SOUTHWESTERLY FLOW...WITH THE 00Z ECMWF SPEEDING IT UP BY ABOUT 24
HOURS FROM ITS PREVIOUS RUN. MEANWHILE...BOTH THE GFS AND GEM ARE
CONSISTENT WITH THEIR EARLIER RUNS. AS A RESULT...WILL FOLLOW THE
GFS/GEM CONSENSUS IN THE EXTENDED...AND BRING RAIN CHANCES BACK INTO
THE PICTURE THURSDAY NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1259 PM CDT SUN MAY 10 2015
A WARM FRONT JUST SOUTH OF MACOMB AND PEORIA AND JUST NORTH OF
BLOOMINGTON WILL CONTINUE TO SLOWLY LIFT NORTH DURING THE
AFTERNOON AND SHOULD PASS THROUGH PIA DURING MID AFTERNOON. IFR
CEILINGS OF 500-1K FT AT PIA NEXT HOUR OR TWO SHOULD LIFT TO MVFR
DURING MID AFTERNOON AS FRONT LIFTS NORTH OF THERE. LIGHT HAZE
WITH VISIBILY OF 5 MILES AT PIA WILL ALSO LIFT ABOVE 6 MILES AS
WARM FRONT PASSES BY AND ENE WINDS 7-10 KTS TO VEER SOUTH. THIS
BOUNDARY WILL SERVE AS A FOCUS FOR SCATTERED SHOWERS AND
THUNDERSTORMS TO DEVELOP IN UNSTABLE AIRMASS DURING MID/LATE
AFTERNOON AND MAINLY AFFECT PIA AND POSSIBLY BMI. BROKEN MVFR
CEILINGS POSSIBLE AT TIMES ACROSS REST OF CENTRAL IL AIRPORTS
WHICH ALL BUT DEC CURRENTLY HAVE. LATEST HIGH RESOLUTION MODELS
BRING CONVECTION FROM WESTERN MO NE ACROSS CENTRAL IL DURING THE
EVENING...REACHING SPI BETWEEN 23Z-00Z AND BMI AND CMI 01-02Z
AND TO BRING VSBYS DOWN TO 2-4 MILES AND MVFR CEILINGS 1-3K FT.
CEILINGS COULD LOWER TO AROUND 1K FT OR LOWER OVERNIGHT IN WARM
MOIST AIRMASS WITH MVFR VSBYS. COLD FRONT TO PUSH EAST INTO
CENTRAL IL BY MIDDAY MONDAY AND RETURN CHANCES OF THUNDERSTORMS
BETWEEN 15-18Z ESPECIALLY OVER EASTERN IL AT BMI...DEC AND
ESPECIALLY CMI. SOUTH WINDS 8-13 KTS WITH GUSTS 15-20 KTS THIS
AFTERNOON TO BE CLOSE TO 10 KTS TONIGHT AND BECOME SW NEAR 15 KTS
WITH GUSTS TO 20 KTS BY 15Z SUNDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
252 PM CDT SAT MAY 9 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 251 PM CDT SAT MAY 9 2015
A QUASI-STATIONARY FRONTAL BOUNDARY FROM JUST SOUTH OF ST LOUIS AND
FLORA TO TERRE HAUTE WILL SLOWLY LIFT BACK NORTH AS A WARM FRONT
TOWARD I-72 TONIGHT (STAYING SOUTH OF I-72 TONIGHT). AREA OF SHOWERS
AND THUNDERSTORMS WITH SOME HEAVY RAIN WAS ALONG AND SOUTH OF A
TAYLORVILLE TO MATTOON TO PARIS LINE AND LIFTING SLOWLY NORTHWARD.
THIS ASSOCIATED WITH MCV EAST OF ST LOUIS AND SLOWLY TRACKING NNE
INTO SW IL AT MID AFTERNOON. SHOWERS AND THUNDERSTORMS WILL SPREAD
NORTHWARD ACROSS CENTRAL IL LATE THIS AFTERNOON AND EVENING WHILE
BECOMING MORE SCATTERED IN SOUTHEAST IL AS THEY GET INTO THE WARM
SECTOR. TAIL END OF HRRR MODEL AND RAP13 MODEL SHOW MORE CONVECTION
SPREADING NE INTO SW CWA LATER TONIGHT AHEAD OF YET ANOTHER MCV OVER
EASTERN OK. SPC KEEPS MARGINAL RISK OF SEVERE STORMS SW OF IL OVER
MO THROUGH TONIGHT. A FEW STRONGER THUNDERSTORMS COULD HAVE WIND
GUSTS OVER 40 MPH WITH PEA SIZE HAIL AND HEAVY RAINS NEAR 1 INCH IN
LESS THAN AN HOUR. LOWS TONIGHT RANGE FROM UPPER 50S TO AROUND 60F
NORTH OF LINCOLN TO THE MID 60S FROM JACKSONVILLE AND SPRINGFIELD TO
MATTOON SOUTH.
&&
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 251 PM CDT SAT MAY 9 2015
UNSETTLED AND UNSEASONABLY MILD WEATHER PATTERN WILL PERSIST ACROSS
CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. STILL A COUPLE MORE
WAVES IN THE PERSISTENT SOUTHWESTERLY FLOW ALOFT NEED TO MOVE
THROUGH THE AREA BEFORE THE VIGOROUS CUT-OFF UPPER LOW OVER THE FOUR
CORNERS REGION FINALLY DRIVES A COLD FRONT THROUGH THE AREA. THIS
FRONT WILL BE FOLLOWED BY COOLER & DRIER AIR FOR MUCH OF THE WORK
WEEK.
SUNDAY SHOULD START OUT WITH SHOWERS/STORMS ACROSS MUCH OF THE
REGION AS A DISTURBANCE, CURRENTLY PRODUCING VIGOROUS CONVECTION
ACROSS THE SOUTHERN PLAINS, TRACKS NORTHEAST ACROSS THE AREA. DO NOT
EXPECT THE MORNING STORMS TO BE SEVERE. THEN, ATTENTION TO THE UPPER
AND ASSOCIATED SURFACE LOW THAT WILL BE PICKING UP STEAM AS IT TRACK
NORTHEAST ACROSS THE PLAINS. A WARM FRONT EXTENDING SOUTHEAST FROM
THE LOW ACROSS THE MIDWEST WILL LIFT NORTH THROUGH THE DAY. STILL
SOME SIGNIFICANT MODEL DISAGREEMENT WITH RESPECT TO HOW QUICKLY THE
FRONT LIFTS NORTHWARD. THE POSITION OF THIS FRONT DURING PEAK
HEATING WILL BE KEY TO WHERE THE BEST SEVERE WEATHER THREAT WILL
EXIST. AT THIS POINT, IT APPEARS THE BEST SHEAR/INSTABILITY WILL CO-
EXIST ACROSS THE NORTHERN PORTION OF THE FORECAST AREA INTO NORTHERN
ILLINOIS. THE SHEAR PROFILES WILL BE SUBSTANTIALLY MORE IMPRESSIVE
FURTHER NORTHWEST, ACROSS IOWA, CLOSER TO THE TRACK OF THE
UPPER/SURFACE LOW. THE LOWS WILL TRACK ACROSS THE GREAT LAKES ON
MONDAY DRAGGING THE TRAILING COLD FRONT THROUGH ILLINOIS. STILL SOME
MODEL DISAGREEMENT IN THE SPEED OF THE COLD FRONT, WHICH WILL BE KEY
TO THE SEVERE WEATHER THREAT ON MONDAY. THE NAM, WHICH HAD BEEN THE
QUICKEST MODEL, IS NOW AMONG THE SLOWEST SOLUTIONS. CONTINUE TO
FAVOR A SLOWER SOLUTION GIVEN THE CURRENT POSITION/SPEED OF THE
SYSTEM OVER THE SOUTHWEST STATES, AND A TYPICAL MODEL BIAS OF BEING
TOO QUICK MOVING CUT-OFF LOWS. THESE FACTORS CONSIDERED, IT APPEARS
THAT THE BEST THREAT FOR SEVERE WEATHER ON MONDAY LOCALLY IS ACROSS
EAST CENTRAL AND SOUTHEAST ILLINOIS DURING THE MONDAY
AFTERNOON/EARLY EVENING HOURS.
QUIETER AND COOLER WEATHER IS EXPECTED TO ARRIVE MONDAY NIGHT AND
LINGER FOR MUCH OF THE REMAINDER OF THE WEEK. DAYTIME HIGHS THAT HAD
FREQUENTLY BEEN IN THE 80S AHEAD OF THE FRONT WILL MAINLY BE IN THE
60S AFTER FRONTAL PASSAGE. THE ECMWF, WHILE SLOWER THAN IT WAS A
COUPLE DAYS AGO, IS STILL THE QUICKEST TO BRING A SYSTEM BACK INTO
THE AREA BY THE END OF THE WEEK AS SOUTHWEST UPPER-LEVEL FLOW
REDEVELOPS AND TEMPERATURES TEND TO CLIMB BACK TOWARD NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1245 PM CDT SAT MAY 9 2015
A FRONTAL BOUNDARY DRAPPED OVER SOUTHERN IL FROM JUST SOUTH OF ST
LOUIS TO VANDALIA TO LAWRENCEVILLE IS STARTING TO LIFT BACK NORTH
AT MIDDAY AND PROJECTED TO LIFT NORTH OF I-70 DURING THE AFTERNOON
BUT TEMPORARILY STALL OUT SOUTH OF I-72 INTO THIS EVENING. SHOWERS
AND THUNDERSTORMS HAVE SPREAD AND DEVELOPED NORTHWARD INTO
SOUTHERN 3 COUNTIES OF CLAY...RICHLAND AND LAWRENCE DURING THE
LUNCH HOUR WITH ISOLATED CONVECTION AS FAR NORTH AS EFFINGHAM AND
ROBINSON. EXPECT THIS CONVECTION TO CONTINUE TO DEVELOP NORTHWARD
TOWARD I-72 DURING MID/LATE AFTERNOON REACHING SPI AND DEC AROUND
20Z-21Z AND CMI AT 21Z AND THEN TO NEAR PIA AND BMI AROUND 22Z
THOUGH PIA AND BMI WILL HAVE BETTER CHANCES OF THUNDERSTORMS AFTER
SUNSET. CEILINGS HAVE LIFTED TO MOSTLY VFR EARLY THIS AFTERNOON
ACROSS CENTRAL IL THOUGH BROKEN 2.5-3K FT WILL OCCUR AT TIMES
ESPECIALLY ALONG I-72 WHERE MORE MOISTURE/A BIT HIGHER DEWPOINTS
ARE AT FURTHER SOUTH. VISIBILITIES COULD LOWER BACK TO MVFR WITH
CONVECTION AND SOME FOG DURING TONIGHT INTO EARLY SUNDAY MORNING.
WARM FRONT THEN LIFTS NORTH TOWARD PIA AND BMI BY MIDDAY SUNDAY.
GENTLE ESE WINDS AROUND 5 KTS THIS AFTERNOON TO BECOME SSE 7-12
KTS SUNDAY MORNING AS WARM FRONT LIFTS NORTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...BAK
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1247 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 1045 AM CDT SAT MAY 9 2015
UPDATED THE FORECAST AT MID MORNING TO REMOVE THE DENSE FOG
ADVISORY AS PATCHY FOG LIFTED ACROSS CENTRAL IL EAST OF THE IL
RIVER BY LATE MORNING. LOWERED CHANCES OF SHOWERS AND
THUNDERSTORMS IN SOUTHEAST IL THIS MORNING AS LINE OF CONVECTION
HAD SHIFTS SOUTH TO NEAR OR SOUTH OF I-64. OTHERWISE REST OF
FORECAST LOOKED GOOD AS CHANCES OF SHOWERS AND THUNDERSTORMS LIFT
NORTHWARD INTO CENTRAL IL DURING THE AFTERNOON ESPECIALLY FROM
I-72 SOUTH. THIS DUE TO FRONTAL BOUNDARY IN SOUTHERN IL LIFTING
BACK NORTH INTO SOUTHERN COUNTIES DURING MID AND LATE AFTERNOON.
INCREASING INSTABILITY DURING THE AFTERNOON FROM I-72 SOUTH WITH
CAPES ELEVATING TO BETWEEN 700-1400 BY LATER THIS AFTERNOON WITH
HIGHEST NUMBERS SOUTH OF I-70. SPC KEEPS MARGINAL RISK OF SEVERE
STORMS SW OF ST LOUIS OVER MO THIS AFTERNOON AND EVENING. PARTLY
TO MOSTLY CLOUDY SKIES TODAY WITH HIGHS IN THE UPPER 70S CENTRAL
IL AND LOWER 80S IN SOUTHEAST IL. DEWPOINTS RANGE FROM UPPER 50S
NW OF IL RIVER TO THE MID 60S IN SOUTHEAST IL.
&&
.SHORT TERM...(TODAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
07Z/2AM SURFACE ANALYSIS SHOWS WEAK LOW PRESSURE ASSOCIATED WITH A
MESOSCALE CONVECTIVE VORTEX (MCV) NEAR KANKAKEE...WITH TRAILING
TROUGH AXIS EXTENDING INTO EAST-CENTRAL ILLINOIS. WHILE MOST OF THE
CONVECTION FROM YESTERDAY AFTERNOON/EVENING HAS LONG SINCE DEPARTED,
A FEW LINGERING SHOWERS PERSIST ALONG THE TROUGH ACROSS THE
SOUTHEAST KILX CWA NEAR I-70. MEANWHILE FURTHER WEST, A COLD FRONT
IS PUSHING INTO THE ILLINOIS RIVER VALLEY. WINDS HAVE SHIFTED TO
THE NORTHWEST AND SLIGHTLY DRIER AIR HAS FILTERED INTO AREAS WEST OF
THE ILLINOIS RIVER WHERE THE CURRENT DEWPOINT AT GALESBURG HAS
DROPPED TO 58. ELSEWHERE AROUND CENTRAL ILLINOIS...WINDS ARE
LIGHT/VARIABLE AND DEWPOINTS REMAIN IN THE LOWER TO MIDDLE 60S.
AREAS OF FOG ARE BEGINNING TO DEVELOP AND SHOULD PERSIST THROUGH
EARLY MORNING. HRRR SUGGESTS PATCHES OF LOCALLY DENSE FOG...HOWEVER
WITH A LIGHT BREEZE EXPECTED THROUGH THE NIGHT DO NOT THINK THIS
WILL BECOME WIDESPREAD ENOUGH TO WARRANT A DENSE FOG ADVISORY. WILL
INSTEAD MENTION PATCHY FOG IN THE FORECAST AND CONTINUE TO MONITOR
VISBY TRENDS AS THE NIGHT PROGRESSES. ONCE ANY MORNING FOG
LIFTS...PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PREVAIL THROUGHOUT
THE DAY. AFTER A LULL IN THE PRECIP CHANCES THROUGH
MIDDAY...ANOTHER MCV ASSOCIATED WITH A CONVECTIVE COMPLEX CURRENTLY
OVER OKLAHOMA WILL APPROACH FROM THE SOUTHWEST LATER TODAY. SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THIS FEATURE MAINLY
ACROSS THE SOUTHERN KILX CWA BY MID TO LATE AFTERNOON.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
SHOWERS AND THUNDERSTORMS WILL BECOME PREVALENT ACROSS ALL OF
CENTRAL ILLINOIS TONIGHT AS THE MCV INTERACTS WITH A DEVELOPING WARM
FRONT. HAVE CARRIED LIKELY POPS ACROSS THE BOARD ACCORDINGLY.
WIDESPREAD CONVECTION WILL BE ONGOING SUNDAY MORNING BEFORE
GRADUALLY LIFTING NORTHWARD INTO WISCONSIN/MICHIGAN. SEVERE WEATHER
THREAT APPEARS TO BE SETTING UP FOR SUNDAY AFTERNOON AND EVENING AS
CLOSED UPPER LOW CURRENTLY OVER THE DESERT SOUTHWEST OPENS AND
EJECTS NORTHEASTWARD INTO THE REGION. CORRESPONDING SURFACE LOW
WILL LIFT FROM NORTHERN KANSAS SUNDAY MORNING TO SOUTHERN MINNESOTA
BY SUNDAY EVENING. BIG QUESTION WILL BE HOW FAR NORTH THE WARM
FRONT WILL GET PULLED, AS LOW-LEVEL WIND SHEAR NEAR THIS BOUNDARY
COULD PROVE PIVOTAL FOR SUPERCELL THUNDERSTORM DEVELOPMENT. GFS
SHOWS THE FRONT LIFTING WELL TO THE NORTH TO NEAR THE WISCONSIN
BORDER BY SUNDAY AFTERNOON; HOWEVER, THE NAM KEEPS IT A BIT FURTHER
SOUTH TOWARD THE I-80 CORRIDOR. TEND TO FAVOR THE HIGHER RESOLUTION
NAM HERE, WHICH COULD PUT THE NORTHERN CWA FROM PEORIA/BLOOMINGTON
NORTHWARD IN AN ENHANCED RISK FOR SEVERE WEATHER. LATEST SPC DAY 2
CONVECTIVE OUTLOOK HIGHLIGHTS IOWA FOR AN ENHANCED SLIGHT RISK FOR
SEVERE SUNDAY AFTERNOON/EVENING...BUT IF THE WARM FRONT IS SLOWER TO
DEPART AS THE NAM SUGGESTS...THIS AREA MAY BE EXPANDED EASTWARD
ACROSS NORTH-CENTRAL ILLINOIS. WILL FEATURE LIKELY POPS EVERYWHERE
DURING THE MORNING AS THE WAA CONVECTION SLOWLY LIFTS NORTHWARD AND
DEPARTS, THEN HAVE DECREASED POPS TO CHANCE FOR THE AFTERNOON.
AS LOW PRESSURE CONTINUES TO TRACK NORTHEASTWARD INTO THE GREAT
LAKES, IT WILL EVENTUALLY DRAG A COLD FRONT THROUGH ILLINOIS ON
MONDAY. MODELS ARE TRENDING FASTER WITH FROPA...WITH MOST SOLUTIONS
SHOWING MAIN LINE OF CONVECTION PASSING EASTWARD INTO INDIANA BY
AFTERNOON. DAY 3 CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK ACROSS
ALL OF CENTRAL ILLINOIS; HOWEVER, THINK THIS MAY GET TRIMMED BACK TO
FEATURE ONLY THE FAR E/SE KILX CWA IF CURRENT TRENDS CONTINUE. WILL
CARRY LIKELY POPS EVERYWHERE SUNDAY NIGHT INTO MONDAY MORNING, THEN
HAVE REMOVED POPS DURING THE AFTERNOON WEST OF THE ILLINOIS RIVER.
FRONT WILL QUICKLY EXIT MONDAY NIGHT...FOLLOWED BY A PERIOD OF
COOLER/DRIER WEATHER TUESDAY THROUGH THURSDAY. HIGH TEMPERATURES
WILL DROP 5 TO 10 DEGREES BELOW NORMAL INTO THE 60S THROUGH THE
PERIOD. THE NEXT CHANCE FOR RAIN WILL HOLD OFF UNTIL THE END OF THE
WEEK WHEN BOTH THE GFS AND ECMWF SHOW A RETURN TO SOUTHWESTERLY
UPPER FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1245 PM CDT SAT MAY 9 2015
A FRONTAL BOUNDARY DRAPPED OVER SOUTHERN IL FROM JUST SOUTH OF ST
LOUIS TO VANDALIA TO LAWRENCEVILLE IS STARTING TO LIFT BACK NORTH
AT MIDDAY AND PROJECTED TO LIFT NORTH OF I-70 DURING THE AFTERNOON
BUT TEMPORARILY STALL OUT SOUTH OF I-72 INTO THIS EVENING. SHOWERS
AND THUNDERSTORMS HAVE SPREAD AND DEVELOPED NORTHWARD INTO
SOUTHERN 3 COUNTIES OF CLAY...RICHLAND AND LAWRENCE DURING THE
LUNCH HOUR WITH ISOLATED CONVECTION AS FAR NORTH AS EFFINGHAM AND
ROBINSON. EXPECT THIS CONVECTION TO CONTINUE TO DEVELOP NORTHWARD
TOWARD I-72 DURING MID/LATE AFTERNOON REACHING SPI AND DEC AROUND
20Z-21Z AND CMI AT 21Z AND THEN TO NEAR PIA AND BMI AROUND 22Z
THOUGH PIA AND BMI WILL HAVE BETTER CHANCES OF THUNDERSTORMS AFTER
SUNSET. CEILINGS HAVE LIFTED TO MOSTLY VFR EARLY THIS AFTERNOON
ACROSS CENTRAL IL THOUGH BROKEN 2.5-3K FT WILL OCCUR AT TIMES
ESPECIALLY ALONG I-72 WHERE MORE MOISTURE/A BIT HIGHER DEWPOINTS
ARE AT FURTHER SOUTH. VISIBILITIES COULD LOWER BACK TO MVFR WITH
CONVECTION AND SOME FOG DURING TONIGHT INTO EARLY SUNDAY MORNING.
WARM FRONT THEN LIFTS NORTH TOWARD PIA AND BMI BY MIDDAY SUNDAY.
GENTLE ESE WINDS AROUND 5 KTS THIS AFTERNOON TO BECOME SSE 7-12
KTS SUNDAY MORNING AS WARM FRONT LIFTS NORTH.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 1045 AM CDT SAT MAY 9 2015
UPDATED THE FORECAST AT MID MORNING TO REMOVE THE DENSE FOG
ADVISORY AS PATCHY FOG LIFTED ACROSS CENTRAL IL EAST OF THE IL
RIVER BY LATE MORNING. LOWERED CHANCES OF SHOWERS AND
THUNDERSTORMS IN SOUTHEAST IL THIS MORNING AS LINE OF CONVECTION
HAD SHIFTS SOUTH TO NEAR OR SOUTH OF I-64. OTHERWISE REST OF
FORECAST LOOKED GOOD AS CHANCES OF SHOWERS AND THUNDERSTORMS LIFT
NORTHWARD INTO CENTRAL IL DURING THE AFTERNOON ESPECIALLY FROM
I-72 SOUTH. THIS DUE TO FRONTAL BOUNDARY IN SOUTHERN IL LIFTING
BACK NORTH INTO SOUTHERN COUNTIES DURING MID AND LATE AFTERNOON.
INCREASING INSTABILITY DURING THE AFTERNOON FROM I-72 SOUTH WITH
CAPES ELEVATING TO BETWEEN 700-1400 BY LATER THIS AFTERNOON WITH
HIGHEST NUMBERS SOUTH OF I-70. PARTLY TO MOSTLY CLOUDY SKIES TODAY
WITH HIGHS IN THE UPPER 70S CENTRAL IL AND LOWER 80S IN SOUTHEAST
IL. DEWPOINTS RANGE FROM UPPER 50S NW OF IL RIVER TO THE MID 60S
IN SOUTHEAST IL.
&&
.SHORT TERM...(TODAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
07Z/2AM SURFACE ANALYSIS SHOWS WEAK LOW PRESSURE ASSOCIATED WITH A
MESOSCALE CONVECTIVE VORTEX (MCV) NEAR KANKAKEE...WITH TRAILING
TROUGH AXIS EXTENDING INTO EAST-CENTRAL ILLINOIS. WHILE MOST OF THE
CONVECTION FROM YESTERDAY AFTERNOON/EVENING HAS LONG SINCE DEPARTED,
A FEW LINGERING SHOWERS PERSIST ALONG THE TROUGH ACROSS THE
SOUTHEAST KILX CWA NEAR I-70. MEANWHILE FURTHER WEST, A COLD FRONT
IS PUSHING INTO THE ILLINOIS RIVER VALLEY. WINDS HAVE SHIFTED TO
THE NORTHWEST AND SLIGHTLY DRIER AIR HAS FILTERED INTO AREAS WEST OF
THE ILLINOIS RIVER WHERE THE CURRENT DEWPOINT AT GALESBURG HAS
DROPPED TO 58. ELSEWHERE AROUND CENTRAL ILLINOIS...WINDS ARE
LIGHT/VARIABLE AND DEWPOINTS REMAIN IN THE LOWER TO MIDDLE 60S.
AREAS OF FOG ARE BEGINNING TO DEVELOP AND SHOULD PERSIST THROUGH
EARLY MORNING. HRRR SUGGESTS PATCHES OF LOCALLY DENSE FOG...HOWEVER
WITH A LIGHT BREEZE EXPECTED THROUGH THE NIGHT DO NOT THINK THIS
WILL BECOME WIDESPREAD ENOUGH TO WARRANT A DENSE FOG ADVISORY. WILL
INSTEAD MENTION PATCHY FOG IN THE FORECAST AND CONTINUE TO MONITOR
VISBY TRENDS AS THE NIGHT PROGRESSES. ONCE ANY MORNING FOG
LIFTS...PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PREVAIL THROUGHOUT
THE DAY. AFTER A LULL IN THE PRECIP CHANCES THROUGH
MIDDAY...ANOTHER MCV ASSOCIATED WITH A CONVECTIVE COMPLEX CURRENTLY
OVER OKLAHOMA WILL APPROACH FROM THE SOUTHWEST LATER TODAY. SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THIS FEATURE MAINLY
ACROSS THE SOUTHERN KILX CWA BY MID TO LATE AFTERNOON.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
SHOWERS AND THUNDERSTORMS WILL BECOME PREVALENT ACROSS ALL OF
CENTRAL ILLINOIS TONIGHT AS THE MCV INTERACTS WITH A DEVELOPING WARM
FRONT. HAVE CARRIED LIKELY POPS ACROSS THE BOARD ACCORDINGLY.
WIDESPREAD CONVECTION WILL BE ONGOING SUNDAY MORNING BEFORE
GRADUALLY LIFTING NORTHWARD INTO WISCONSIN/MICHIGAN. SEVERE WEATHER
THREAT APPEARS TO BE SETTING UP FOR SUNDAY AFTERNOON AND EVENING AS
CLOSED UPPER LOW CURRENTLY OVER THE DESERT SOUTHWEST OPENS AND
EJECTS NORTHEASTWARD INTO THE REGION. CORRESPONDING SURFACE LOW
WILL LIFT FROM NORTHERN KANSAS SUNDAY MORNING TO SOUTHERN MINNESOTA
BY SUNDAY EVENING. BIG QUESTION WILL BE HOW FAR NORTH THE WARM
FRONT WILL GET PULLED, AS LOW-LEVEL WIND SHEAR NEAR THIS BOUNDARY
COULD PROVE PIVOTAL FOR SUPERCELL THUNDERSTORM DEVELOPMENT. GFS
SHOWS THE FRONT LIFTING WELL TO THE NORTH TO NEAR THE WISCONSIN
BORDER BY SUNDAY AFTERNOON; HOWEVER, THE NAM KEEPS IT A BIT FURTHER
SOUTH TOWARD THE I-80 CORRIDOR. TEND TO FAVOR THE HIGHER RESOLUTION
NAM HERE, WHICH COULD PUT THE NORTHERN CWA FROM PEORIA/BLOOMINGTON
NORTHWARD IN AN ENHANCED RISK FOR SEVERE WEATHER. LATEST SPC DAY 2
CONVECTIVE OUTLOOK HIGHLIGHTS IOWA FOR AN ENHANCED SLIGHT RISK FOR
SEVERE SUNDAY AFTERNOON/EVENING...BUT IF THE WARM FRONT IS SLOWER TO
DEPART AS THE NAM SUGGESTS...THIS AREA MAY BE EXPANDED EASTWARD
ACROSS NORTH-CENTRAL ILLINOIS. WILL FEATURE LIKELY POPS EVERYWHERE
DURING THE MORNING AS THE WAA CONVECTION SLOWLY LIFTS NORTHWARD AND
DEPARTS, THEN HAVE DECREASED POPS TO CHANCE FOR THE AFTERNOON.
AS LOW PRESSURE CONTINUES TO TRACK NORTHEASTWARD INTO THE GREAT
LAKES, IT WILL EVENTUALLY DRAG A COLD FRONT THROUGH ILLINOIS ON
MONDAY. MODELS ARE TRENDING FASTER WITH FROPA...WITH MOST SOLUTIONS
SHOWING MAIN LINE OF CONVECTION PASSING EASTWARD INTO INDIANA BY
AFTERNOON. DAY 3 CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK ACROSS
ALL OF CENTRAL ILLINOIS; HOWEVER, THINK THIS MAY GET TRIMMED BACK TO
FEATURE ONLY THE FAR E/SE KILX CWA IF CURRENT TRENDS CONTINUE. WILL
CARRY LIKELY POPS EVERYWHERE SUNDAY NIGHT INTO MONDAY MORNING, THEN
HAVE REMOVED POPS DURING THE AFTERNOON WEST OF THE ILLINOIS RIVER.
FRONT WILL QUICKLY EXIT MONDAY NIGHT...FOLLOWED BY A PERIOD OF
COOLER/DRIER WEATHER TUESDAY THROUGH THURSDAY. HIGH TEMPERATURES
WILL DROP 5 TO 10 DEGREES BELOW NORMAL INTO THE 60S THROUGH THE
PERIOD. THE NEXT CHANCE FOR RAIN WILL HOLD OFF UNTIL THE END OF THE
WEEK WHEN BOTH THE GFS AND ECMWF SHOW A RETURN TO SOUTHWESTERLY
UPPER FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT MAY 9 2015
LIFR/IFR CONDITIONS ARE EXPECTED TO GRADUALLY IMPROVE IN THE
13Z-15Z TIME FRAME WITH THE FOG LIFTING BUT IFR TO MVFR CIGS
PREVAILING EAST OF THE IL.RIVER UNTIL AROUND 16Z. WEAK FRONTAL
BOUNDARY ACROSS WEST CENTRAL IL IS EXPECTED TO SLOWLY EDGE EAST
AND SOUTH TODAY WITH SOMEWHAT DRIER AIR TO ITS WEST EXPECTED
TO ADVECT INTO THE FORECAST AREA LATE THIS MORNING INTO THE
AFTERNOON HOURS WHICH SHOULD BRING ABOUT IMPROVING CIGS AND
VSBYS. ONCE WE SCOUR OUT THE LOW LEVEL CLOUDS...FORECAST
SOUNDINGS SUGGEST A QUICK INCREASE IN CUMULUS CLOUDS BY EARLY
THIS AFTERNOON THANKS TO THE ABUNDANT MOISTURE IN THE LOW
LEVELS. LOOKS AS IF CLOUD BASES WILL BE AROUND 3500-4500 FEET. A
WEATHER DISTURBANCE IS EXPECTED TO PUSH NORTHEAST OUT OF MISSOURI
THIS AFTERNOON AND MAY BRING SOME SCATTERED SHOWERS AND STORMS
TO OUR SOUTHERN TAF SITES BUT WILL ONLY INCLUDE VCTS AT THIS TIME
AS COVERAGE LOOKS RATHER LIMITED AT THIS TIME. A WARM FRONT IS
THEN EXPECTED TO PUSH NORTH LATER TONIGHT WHICH WILL BRING ABOUT
LOWER CIGS AND VSBYS AGAIN IN RAIN AND ISOLD TSRA. SURFACE WINDS
WILL BE LIGHT EAST TO SOUTHEAST TODAY AND EAST AT 5 TO 10 KTS
TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
603 AM CDT SAT MAY 9 2015
.SHORT TERM...(TODAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
07Z/2AM SURFACE ANALYSIS SHOWS WEAK LOW PRESSURE ASSOCIATED WITH A
MESOSCALE CONVECTIVE VORTEX (MCV) NEAR KANKAKEE...WITH TRAILING
TROUGH AXIS EXTENDING INTO EAST-CENTRAL ILLINOIS. WHILE MOST OF THE
CONVECTION FROM YESTERDAY AFTERNOON/EVENING HAS LONG SINCE DEPARTED,
A FEW LINGERING SHOWERS PERSIST ALONG THE TROUGH ACROSS THE
SOUTHEAST KILX CWA NEAR I-70. MEANWHILE FURTHER WEST, A COLD FRONT
IS PUSHING INTO THE ILLINOIS RIVER VALLEY. WINDS HAVE SHIFTED TO
THE NORTHWEST AND SLIGHTLY DRIER AIR HAS FILTERED INTO AREAS WEST OF
THE ILLINOIS RIVER WHERE THE CURRENT DEWPOINT AT GALESBURG HAS
DROPPED TO 58. ELSEWHERE AROUND CENTRAL ILLINOIS...WINDS ARE
LIGHT/VARIABLE AND DEWPOINTS REMAIN IN THE LOWER TO MIDDLE 60S.
AREAS OF FOG ARE BEGINNING TO DEVELOP AND SHOULD PERSIST THROUGH
EARLY MORNING. HRRR SUGGESTS PATCHES OF LOCALLY DENSE FOG...HOWEVER
WITH A LIGHT BREEZE EXPECTED THROUGH THE NIGHT DO NOT THINK THIS
WILL BECOME WIDESPREAD ENOUGH TO WARRANT A DENSE FOG ADVISORY. WILL
INSTEAD MENTION PATCHY FOG IN THE FORECAST AND CONTINUE TO MONITOR
VISBY TRENDS AS THE NIGHT PROGRESSES. ONCE ANY MORNING FOG
LIFTS...PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PREVAIL THROUGHOUT
THE DAY. AFTER A LULL IN THE PRECIP CHANCES THROUGH
MIDDAY...ANOTHER MCV ASSOCIATED WITH A CONVECTIVE COMPLEX CURRENTLY
OVER OKLAHOMA WILL APPROACH FROM THE SOUTHWEST LATER TODAY. SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THIS FEATURE MAINLY
ACROSS THE SOUTHERN KILX CWA BY MID TO LATE AFTERNOON.
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
SHOWERS AND THUNDERSTORMS WILL BECOME PREVALENT ACROSS ALL OF
CENTRAL ILLINOIS TONIGHT AS THE MCV INTERACTS WITH A DEVELOPING WARM
FRONT. HAVE CARRIED LIKELY POPS ACROSS THE BOARD ACCORDINGLY.
WIDESPREAD CONVECTION WILL BE ONGOING SUNDAY MORNING BEFORE
GRADUALLY LIFTING NORTHWARD INTO WISCONSIN/MICHIGAN. SEVERE WEATHER
THREAT APPEARS TO BE SETTING UP FOR SUNDAY AFTERNOON AND EVENING AS
CLOSED UPPER LOW CURRENTLY OVER THE DESERT SOUTHWEST OPENS AND
EJECTS NORTHEASTWARD INTO THE REGION. CORRESPONDING SURFACE LOW
WILL LIFT FROM NORTHERN KANSAS SUNDAY MORNING TO SOUTHERN MINNESOTA
BY SUNDAY EVENING. BIG QUESTION WILL BE HOW FAR NORTH THE WARM
FRONT WILL GET PULLED, AS LOW-LEVEL WIND SHEAR NEAR THIS BOUNDARY
COULD PROVE PIVOTAL FOR SUPERCELL THUNDERSTORM DEVELOPMENT. GFS
SHOWS THE FRONT LIFTING WELL TO THE NORTH TO NEAR THE WISCONSIN
BORDER BY SUNDAY AFTERNOON; HOWEVER, THE NAM KEEPS IT A BIT FURTHER
SOUTH TOWARD THE I-80 CORRIDOR. TEND TO FAVOR THE HIGHER RESOLUTION
NAM HERE, WHICH COULD PUT THE NORTHERN CWA FROM PEORIA/BLOOMINGTON
NORTHWARD IN AN ENHANCED RISK FOR SEVERE WEATHER. LATEST SPC DAY 2
CONVECTIVE OUTLOOK HIGHLIGHTS IOWA FOR AN ENHANCED SLIGHT RISK FOR
SEVERE SUNDAY AFTERNOON/EVENING...BUT IF THE WARM FRONT IS SLOWER TO
DEPART AS THE NAM SUGGESTS...THIS AREA MAY BE EXPANDED EASTWARD
ACROSS NORTH-CENTRAL ILLINOIS. WILL FEATURE LIKELY POPS EVERYWHERE
DURING THE MORNING AS THE WAA CONVECTION SLOWLY LIFTS NORTHWARD AND
DEPARTS, THEN HAVE DECREASED POPS TO CHANCE FOR THE AFTERNOON.
AS LOW PRESSURE CONTINUES TO TRACK NORTHEASTWARD INTO THE GREAT
LAKES, IT WILL EVENTUALLY DRAG A COLD FRONT THROUGH ILLINOIS ON
MONDAY. MODELS ARE TRENDING FASTER WITH FROPA...WITH MOST SOLUTIONS
SHOWING MAIN LINE OF CONVECTION PASSING EASTWARD INTO INDIANA BY
AFTERNOON. DAY 3 CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK ACROSS
ALL OF CENTRAL ILLINOIS; HOWEVER, THINK THIS MAY GET TRIMMED BACK TO
FEATURE ONLY THE FAR E/SE KILX CWA IF CURRENT TRENDS CONTINUE. WILL
CARRY LIKELY POPS EVERYWHERE SUNDAY NIGHT INTO MONDAY MORNING, THEN
HAVE REMOVED POPS DURING THE AFTERNOON WEST OF THE ILLINOIS RIVER.
FRONT WILL QUICKLY EXIT MONDAY NIGHT...FOLLOWED BY A PERIOD OF
COOLER/DRIER WEATHER TUESDAY THROUGH THURSDAY. HIGH TEMPERATURES
WILL DROP 5 TO 10 DEGREES BELOW NORMAL INTO THE 60S THROUGH THE
PERIOD. THE NEXT CHANCE FOR RAIN WILL HOLD OFF UNTIL THE END OF THE
WEEK WHEN BOTH THE GFS AND ECMWF SHOW A RETURN TO SOUTHWESTERLY
UPPER FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CDT SAT MAY 9 2015
LIFR/IFR CONDITIONS ARE EXPECTED TO GRADUALLY IMPROVE IN THE
13Z-15Z TIME FRAME WITH THE FOG LIFTING BUT IFR TO MVFR CIGS
PREVAILING EAST OF THE IL.RIVER UNTIL AROUND 16Z. WEAK FRONTAL
BOUNDARY ACROSS WEST CENTRAL IL IS EXPECTED TO SLOWLY EDGE EAST
AND SOUTH TODAY WITH SOMEWHAT DRIER AIR TO ITS WEST EXPECTED
TO ADVECT INTO THE FORECAST AREA LATE THIS MORNING INTO THE
AFTERNOON HOURS WHICH SHOULD BRING ABOUT IMPROVING CIGS AND
VSBYS. ONCE WE SCOUR OUT THE LOW LEVEL CLOUDS...FORECAST
SOUNDINGS SUGGEST A QUICK INCREASE IN CUMULUS CLOUDS BY EARLY
THIS AFTERNOON THANKS TO THE ABUNDANT MOISTURE IN THE LOW
LEVELS. LOOKS AS IF CLOUD BASES WILL BE AROUND 3500-4500 FEET. A
WEATHER DISTURBANCE IS EXPECTED TO PUSH NORTHEAST OUT OF MISSOURI
THIS AFTERNOON AND MAY BRING SOME SCATTERED SHOWERS AND STORMS
TO OUR SOUTHERN TAF SITES BUT WILL ONLY INCLUDE VCTS AT THIS TIME
AS COVERAGE LOOKS RATHER LIMITED AT THIS TIME. A WARM FRONT IS
THEN EXPECTED TO PUSH NORTH LATER TONIGHT WHICH WILL BRING ABOUT
LOWER CIGS AND VSBYS AGAIN IN RAIN AND ISOLD TSRA. SURFACE WINDS
WILL BE LIGHT EAST TO SOUTHEAST TODAY AND EAST AT 5 TO 10 KTS
TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
325 AM CDT SAT MAY 9 2015
.SHORT TERM...(TODAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
07Z/2AM SURFACE ANALYSIS SHOWS WEAK LOW PRESSURE ASSOCIATED WITH A
MESOSCALE CONVECTIVE VORTEX (MCV) NEAR KANKAKEE...WITH TRAILING
TROUGH AXIS EXTENDING INTO EAST-CENTRAL ILLINOIS. WHILE MOST OF THE
CONVECTION FROM YESTERDAY AFTERNOON/EVENING HAS LONG SINCE DEPARTED,
A FEW LINGERING SHOWERS PERSIST ALONG THE TROUGH ACROSS THE
SOUTHEAST KILX CWA NEAR I-70. MEANWHILE FURTHER WEST, A COLD FRONT
IS PUSHING INTO THE ILLINOIS RIVER VALLEY. WINDS HAVE SHIFTED TO
THE NORTHWEST AND SLIGHTLY DRIER AIR HAS FILTERED INTO AREAS WEST OF
THE ILLINOIS RIVER WHERE THE CURRENT DEWPOINT AT GALESBURG HAS
DROPPED TO 58. ELSEWHERE AROUND CENTRAL ILLINOIS...WINDS ARE
LIGHT/VARIABLE AND DEWPOINTS REMAIN IN THE LOWER TO MIDDLE 60S.
AREAS OF FOG ARE BEGINNING TO DEVELOP AND SHOULD PERSIST THROUGH
EARLY MORNING. HRRR SUGGESTS PATCHES OF LOCALLY DENSE FOG...HOWEVER
WITH A LIGHT BREEZE EXPECTED THROUGH THE NIGHT DO NOT THINK THIS
WILL BECOME WIDESPREAD ENOUGH TO WARRANT A DENSE FOG ADVISORY. WILL
INSTEAD MENTION PATCHY FOG IN THE FORECAST AND CONTINUE TO MONITOR
VISBY TRENDS AS THE NIGHT PROGRESSES. ONCE ANY MORNING FOG
LIFTS...PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PREVAIL THROUGHOUT
THE DAY. AFTER A LULL IN THE PRECIP CHANCES THROUGH
MIDDAY...ANOTHER MCV ASSOCIATED WITH A CONVECTIVE COMPLEX CURRENTLY
OVER OKLAHOMA WILL APPROACH FROM THE SOUTHWEST LATER TODAY. SHOWERS
AND THUNDERSTORMS WILL DEVELOP IN ADVANCE OF THIS FEATURE MAINLY
ACROSS THE SOUTHERN KILX CWA BY MID TO LATE AFTERNOON.
&&
.LONG TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 325 AM CDT SAT MAY 9 2015
SHOWERS AND THUNDERSTORMS WILL BECOME PREVALENT ACROSS ALL OF
CENTRAL ILLINOIS TONIGHT AS THE MCV INTERACTS WITH A DEVELOPING WARM
FRONT. HAVE CARRIED LIKELY POPS ACROSS THE BOARD ACCORDINGLY.
WIDESPREAD CONVECTION WILL BE ONGOING SUNDAY MORNING BEFORE
GRADUALLY LIFTING NORTHWARD INTO WISCONSIN/MICHIGAN. SEVERE WEATHER
THREAT APPEARS TO BE SETTING UP FOR SUNDAY AFTERNOON AND EVENING AS
CLOSED UPPER LOW CURRENTLY OVER THE DESERT SOUTHWEST OPENS AND
EJECTS NORTHEASTWARD INTO THE REGION. CORRESPONDING SURFACE LOW
WILL LIFT FROM NORTHERN KANSAS SUNDAY MORNING TO SOUTHERN MINNESOTA
BY SUNDAY EVENING. BIG QUESTION WILL BE HOW FAR NORTH THE WARM
FRONT WILL GET PULLED, AS LOW-LEVEL WIND SHEAR NEAR THIS BOUNDARY
COULD PROVE PIVOTAL FOR SUPERCELL THUNDERSTORM DEVELOPMENT. GFS
SHOWS THE FRONT LIFTING WELL TO THE NORTH TO NEAR THE WISCONSIN
BORDER BY SUNDAY AFTERNOON; HOWEVER, THE NAM KEEPS IT A BIT FURTHER
SOUTH TOWARD THE I-80 CORRIDOR. TEND TO FAVOR THE HIGHER RESOLUTION
NAM HERE, WHICH COULD PUT THE NORTHERN CWA FROM PEORIA/BLOOMINGTON
NORTHWARD IN AN ENHANCED RISK FOR SEVERE WEATHER. LATEST SPC DAY 2
CONVECTIVE OUTLOOK HIGHLIGHTS IOWA FOR AN ENHANCED SLIGHT RISK FOR
SEVERE SUNDAY AFTERNOON/EVENING...BUT IF THE WARM FRONT IS SLOWER TO
DEPART AS THE NAM SUGGESTS...THIS AREA MAY BE EXPANDED EASTWARD
ACROSS NORTH-CENTRAL ILLINOIS. WILL FEATURE LIKELY POPS EVERYWHERE
DURING THE MORNING AS THE WAA CONVECTION SLOWLY LIFTS NORTHWARD AND
DEPARTS, THEN HAVE DECREASED POPS TO CHANCE FOR THE AFTERNOON.
AS LOW PRESSURE CONTINUES TO TRACK NORTHEASTWARD INTO THE GREAT
LAKES, IT WILL EVENTUALLY DRAG A COLD FRONT THROUGH ILLINOIS ON
MONDAY. MODELS ARE TRENDING FASTER WITH FROPA...WITH MOST SOLUTIONS
SHOWING MAIN LINE OF CONVECTION PASSING EASTWARD INTO INDIANA BY
AFTERNOON. DAY 3 CONVECTIVE OUTLOOK INDICATES A SLIGHT RISK ACROSS
ALL OF CENTRAL ILLINOIS; HOWEVER, THINK THIS MAY GET TRIMMED BACK TO
FEATURE ONLY THE FAR E/SE KILX CWA IF CURRENT TRENDS CONTINUE. WILL
CARRY LIKELY POPS EVERYWHERE SUNDAY NIGHT INTO MONDAY MORNING, THEN
HAVE REMOVED POPS DURING THE AFTERNOON WEST OF THE ILLINOIS RIVER.
FRONT WILL QUICKLY EXIT MONDAY NIGHT...FOLLOWED BY A PERIOD OF
COOLER/DRIER WEATHER TUESDAY THROUGH THURSDAY. HIGH TEMPERATURES
WILL DROP 5 TO 10 DEGREES BELOW NORMAL INTO THE 60S THROUGH THE
PERIOD. THE NEXT CHANCE FOR RAIN WILL HOLD OFF UNTIL THE END OF THE
WEEK WHEN BOTH THE GFS AND ECMWF SHOW A RETURN TO SOUTHWESTERLY
UPPER FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1203 AM CDT SAT MAY 9 2015
LOTS OF LOW LEVEL MOISTURE, LIGHT WINDS, AND SCT TO BKN CLOUDS
OVER THE AREA EFFECTING ALL TAF SITES. THROUGH VIS AT ALL TAF
SITES IS P6SM, EXPECTING INTERMITTENT PERIODS OF LOWER VIS.
STRATUS IS ALSO AROUND BECAUSE OF THE LOW LEVEL MOISTURE, SO WILL
KEEP 4HR TEMPO GROUP AT ALL SITES FOR BKN IFR CIGS AND LOWER VIS.
BY MORNING ONCE LIGHT FOG BURNS OFF, LOWER CLOUDS WILL GO AWAY
TOO. BLOW OFF FROM LARGE COMPLEX OF STORMS OUT WEST WILL
OVERSPREAD THE AREA IN THE MORNING AND LAST THROUGH THE AFTERNOON.
THEN EXPECTING MID CLOUDS TO ADVECT INTO THE AREA TOMORROW
EVENING. ANY PCPN SHOULD REMAIN SOUTH OF THE TAFS. WINDS WILL BE
LIGHT AND VARIABLE THROUGH MOST OF THE PERIOD AND THEN BECOME
EASTERLY TOMORROW EVENING AS A WARM FRONT SETS UP ACROSS THE AREA.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1030 PM EDT SUN MAY 10 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 250 PM EDT SUN MAY 10 2015
A COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TONIGHT AND
MONDAY. SOME SEVERE STORMS ARE POSSIBLE MONDAY WITH THE FRONT. DRIER
AND MUCH COOLER AIR WILL MOVE IN FOR MID WEEK. WARMER TEMPERATURES
WILL RETURN BY NEXT WEEKEND BUT SO WILL RAIN CHANCES AS A WARM FRONT
MOVES INTO THE AREA.
&&
.NEAR TERM.../REST OF THIS EVENING AND OVERNIGHT/
ISSUED AT 944 PM EDT SUN MAY 10 2015
HAD TO INCREASE POPS ACROSS ROUGHLY THE WESTERN HALF OF THE FORECAST
AREA AS SOLID LINE OF THUNDERSTORMS WAS LIFTING NORTHEAST INTO KNOX
COUNTY AT THE PRESENT TIME. THIS LINE WILL CONTINUE TO LIFT
NORTHEAST AROUND 40 MPH THROUGH THE EARLY OVERNIGHT. A SLIGHT RISK
OF SEVERE STORMS HAS BEEN EXTENDED EAST TO OUR FAR WESTERN
COUNTIES...PRIMARILY DUE TO THE RISK OF STORMS WITH THE LINE THIS
EVENING. THIS LOOKS REASONABLE WITH RECENT REPORTS OF 60 PLUS MPH
WITH THE LINE OVER EAST CENTRAL ILLINOIS. UPDATED THE ZONES AND
HAZARDOUS WEATHER OUTLOOK TO REFLECT THIS.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 250 PM EDT SUN MAY 10 2015
SCATTERED CONVECTION CONTINUES TO FIRE ACROSS PORTIONS OF THE
FORECAST AREA THIS AFTERNOON AS THE TAIL OF AN UPPER WAVE REMAINS
ACROSS THE AREA. INSTABILITY WILL CONTINUE TO BUILD THIS AFTERNOON
AS SATELLITE SHOWS SOME PARTIAL CLEARING...SO WOULD NOT BE SURPRISED
TO SEE ADDITIONAL CONVECTION POP UP. WILL CONTINUE WITH CHANCE POPS.
SOME UNCERTAINTY IN RAIN CHANCES INCREASES TONIGHT AS THE EVOLUTION
OF A CONVECTIVE LINE REMAINS IN DOUBT. REMNANT OF A CONVECTIVE LINE
ACROSS MISSOURI WILL ATTEMPT TO MOVE INTO THE AREA EARLY THIS
EVENING. MAJORITY OF THE FORCING THAT INITIATED THIS LINE WILL
REMAIN WEST OF THE AREA THIS EVENING...SO A WEAKENING TREND IS
EXPECTED AS IT MOVES TOWARD AND EVENTUALLY INTO THE AREA.
THERE WILL BE INSTABILITY OVER THE AREA THOUGH SO SOME OF IT SHOULD
MAKE IT IN. WILL GO HIGHER CHANCE CATEGORY POPS THIS EVENING
WEST AND LOW EAST TO ACCOUNT FOR THE WEAKENING LINE.
OVERNIGHT MODELS TRY TO GENERATE SOME ADDITIONAL CONVECTION WITH
ANOTHER UPPER IMPULSE AHEAD OF THE COLD FRONT. THERE IS SOME
ISENTROPIC LIFT BUT BEST FORCING REMAINS JUST WEST OF THE AREA WITH
THE COLD FRONT. WENT LIKELY POPS NORTHWEST QUARTER OF THE AREA RIGHT
NEAR 12Z WITH CHANCE POPS ELSEWHERE BY THEN.
STUCK WITH A MODEL BLEND FOR TEMPERATURES WITH CLOUDS AND SOME RAIN
AROUND TONIGHT.
&&
.SHORT TERM.../MONDAY THROUGH WEDNESDAY/
ISSUED AT 250 PM EDT SUN MAY 10 2015
FOCUS IS ON RAIN/SEVERE CHANCES ON MONDAY. MODELS ARE CLOSE ENOUGH
THAT A BLEND WAS USED.
PLENTY OF UNCERTAINTY IN CONVECTIVE DEVELOPMENT ON MONDAY. FIRST
POSSIBLE SCENARIO IS THAT DYING AREA OF SHOWERS AND THUNDERSTORMS
MOVE IN DURING THE MORNING WHICH WOULD KEEP CLOUDS AROUND AND
TEMPERATURES DOWN DURING THE DAY...LOWERING THE INSTABILITY AND
THUNDERSTORM CHANCES.
SECOND SCENARIO IS ANY LINGERING CONVECTION AND ITS ASSOCIATED
CLOUDINESS DISSIPATE QUICKLY IN THE MORNING ALLOWING SOME PARTIAL
SUN AND GREATER INSTABILITY...AND THUS BETTER CHANCES FOR SEVERE.
AT ANY RATE AT LEAST SOME RAIN IS A GOOD BET AT SOME POINT ON MONDAY
AS THE STRONG COLD FRONT HAS 40-50KT 850MB WINDS AND THE RIGHT
ENTRANCE REGION OF AN UPPER JET TO AID IN THE FORCING.
THUS WENT CATEGORICAL POPS AT SOME POINT DURING THE DAY ALL AREAS ON
MONDAY. WENT HIGHER POPS EARLIER IN THE DAY WEST AND LATER IN THE
DAY EAST TO ACCOUNT FOR TIMING OF FRONT. WILL CONTINUE TO MENTION
SEVERE POTENTIAL WITH THE GOOD WIND FIELDS AND POSSIBILITY OF
GREATER INSTABILITY IF SCENARIO 2 ABOVE PANS OUT.
KEPT SOME LINGERING CHANCES FOR RAIN MONDAY EVENING ACROSS THE EAST
AS THE FRONT EXITS THE AREA. DRY AIR AND HIGH PRESSURE WILL THEN
BUILD INTO THE AREA FOR TUESDAY AND WEDNESDAY.
ON TUESDAY THERE WILL BE MORE CLOUDS NORTH AS AN UPPER LOW PASSES
ACROSS THE GREAT LAKES AND COLD AIR ALOFT MOVES IN. A DECENT WIND
FIELD ALOFT WILL PARTIALLY MIX DOWN AND PROVIDE WIND GUSTS AROUND 25
MPH DURING THE DAY.
WEDNESDAY WILL SEE FEWER CLOUDS AND WEAKER WINDS WITH HIGH PRESSURE
BUILDING IN.
WITH THE UNCERTAINTY IN CLOUDS ON MONDAY STUCK WITH A MODEL BLEND
FOR HIGH TEMPERATURES. TRENDED TOWARD THE COOLER OF THE MOS NUMBERS
FOR HIGHS ON TUESDAY WITH THE ADDITIONAL CLOUDS AND COLD AIR ALOFT.
OTHERWISE STUCK WITH A BLEND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 250 PM EDT SUN MAY 10 2015
MODELS INDICATE A PROGRESSIVE UPPER FLOW WILL OCCUR THE LATER HALF
OF THIS WEEK AND EARLY NEXT WEEK. HIGH PRESSURE ACROSS THE GREAT
LAKES WEDNESDAY NIGHT WILL MOVE TO THE NEW ENGLAND COAST BY FRIDAY.
AN UPPER RIDGE OVER THE CENTRAL U.S. EARLY ON WILL MOVE TO THE
APPALACHIANS BY SUNDAY. WEDNESDAY NIGHT AND THURSDAY SHOULD BE DRY
AS HIGH PRESSURE CONTINUES TO CONTROL OUR WEATHER. WILL MENTION
INCREASING CHANCES OF SHOWERS THURSDAY NIGHT AND THEN WILL GO WITH
CHANCE POPS REST OF THE LONG TERM.
MU CAPES ARE QUITE LOW THROUGH FRIDAY NIGHT...SO LEANED MORE TOWARDS
CHANCE OF SHOWERS RATHER THAN THUNDERSTORMS THURSDAY NIGHT AND
FRIDAY. DID MENTION A CHANCE OF THUNDER ACROSS SOUTHWEST PORTIONS
HOWEVER TO BLEND IN WITH OFFICES TO OUR SOUTHWEST. AIRMASS WILL
BECOME MORE UNSTABLE BY THE WEEKEND AS A WARM FRONT MOVES INTO OUR
AREA...SO LEANED MORE TOWARDS CHANCE OF THUNDERSTORMS OVER THE
WEEKEND. ON TEMPERATURES WENT CLOSE TO A MODEL BLEND MOST PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 11/00Z TAFS/...
ISSUED AT 1030 PM EDT SUN MAY 10 2015
ADDED A TEMPO GROUP FOR LINE OF THUNDERSTORMS WHICH WILL LIKELY
IMPACT IND AS EARLY AS 03Z. WEST WINDS MAY GUST INTO THE 35KT RANGE
FOR A TIME. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 713 PM EDT SUN MAY 10 2015
MAINLY VFR THROUGH THE PERIOD OUTSIDE OF ANY SHOWERS OR
THUNDERSTORMS. RAPIDLY FLUCTUATING CONDITIONS POSSIBLE IN CONVECTION.
APPEARS THAT A WEAKENING LINE OF THUNDERSTORMS MAY SWEEP ACROSS THE
SITES LATER THIS EVENING...AND WILL CARRY A VCTS MENTION FOR A TIME
TO ACCOUNT FOR THIS. HRRR NOW SUPPORTS THIS AFTER DISSIPATING THE
LINE IN EARLIER RUNS.
SHOULD BE A BREAK IN CONVECTION ASIDE FROM ISOLATED SHOWERS/STORMS
THAT ARE NEARLY IMPOSSIBLE TO TIME AND PLACE...BEFORE ANOTHER MORE
SUBSTANTIAL DISTURBANCE MOVES INTO THE AREA NEAR DAYBREAK
TOMORROW...BRINGING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS BACK
TO THE AREA. GOING TAF HANDLED THIS FAIRLY WELL.
WINDS WILL GENERALLY BE SOUTHERLY OR SOUTHWESTERLY AS HIGH AS 10 TO
15KT OVERNIGHT WITH SOME GUSTS INTO THE MID 20KT RANGE LIKELY
TOMORROW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/MK
SHORT TERM...50
LONG TERM...JH
AVIATION...NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
944 PM EDT SUN MAY 10 2015
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 250 PM EDT SUN MAY 10 2015
A COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TONIGHT AND
MONDAY. SOME SEVERE STORMS ARE POSSIBLE MONDAY WITH THE FRONT. DRIER
AND MUCH COOLER AIR WILL MOVE IN FOR MID WEEK. WARMER TEMPERATURES
WILL RETURN BY NEXT WEEKEND BUT SO WILL RAIN CHANCES AS A WARM FRONT
MOVES INTO THE AREA.
&&
.NEAR TERM.../REST OF THIS EVENING AND OVERNIGHT/
ISSUED AT 944 PM EDT SUN MAY 10 2015
HAD TO INCREASE POPS ACROSS ROUGHLY THE WESTERN HALF OF THE FORECAST
AREA AS SOLID LINE OF THUNDERSTORMS WAS LIFTING NORTHEAST INTO KNOX
COUNTY AT THE PRESENT TIME. THIS LINE WILL CONTINUE TO LIFT
NORTHEAST AROUND 40 MPH THROUGH THE EARLY OVERNIGHT. A SLIGHT RISK
OF SEVERE STORMS HAS BEEN EXTENDED EAST TO OUR FAR WESTERN
COUNTIES...PRIMARILY DUE TO THE RISK OF STORMS WITH THE LINE THIS
EVENING. THIS LOOKS REASONABLE WITH RECENT REPORTS OF 60 PLUS MPH
WITH THE LINE OVER EAST CENTRAL ILLINOIS. UPDATED THE ZONES AND
HAZARDOUS WEATHER OUTLOOK TO REFLECT THIS.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 250 PM EDT SUN MAY 10 2015
SCATTERED CONVECTION CONTINUES TO FIRE ACROSS PORTIONS OF THE
FORECAST AREA THIS AFTERNOON AS THE TAIL OF AN UPPER WAVE REMAINS
ACROSS THE AREA. INSTABILITY WILL CONTINUE TO BUILD THIS AFTERNOON
AS SATELLITE SHOWS SOME PARTIAL CLEARING...SO WOULD NOT BE SURPRISED
TO SEE ADDITIONAL CONVECTION POP UP. WILL CONTINUE WITH CHANCE POPS.
SOME UNCERTAINTY IN RAIN CHANCES INCREASES TONIGHT AS THE EVOLUTION
OF A CONVECTIVE LINE REMAINS IN DOUBT. REMNANT OF A CONVECTIVE LINE
ACROSS MISSOURI WILL ATTEMPT TO MOVE INTO THE AREA EARLY THIS
EVENING. MAJORITY OF THE FORCING THAT INITIATED THIS LINE WILL
REMAIN WEST OF THE AREA THIS EVENING...SO A WEAKENING TREND IS
EXPECTED AS IT MOVES TOWARD AND EVENTUALLY INTO THE AREA.
THERE WILL BE INSTABILITY OVER THE AREA THOUGH SO SOME OF IT SHOULD
MAKE IT IN. WILL GO HIGHER CHANCE CATEGORY POPS THIS EVENING
WEST AND LOW EAST TO ACCOUNT FOR THE WEAKENING LINE.
OVERNIGHT MODELS TRY TO GENERATE SOME ADDITIONAL CONVECTION WITH
ANOTHER UPPER IMPULSE AHEAD OF THE COLD FRONT. THERE IS SOME
ISENTROPIC LIFT BUT BEST FORCING REMAINS JUST WEST OF THE AREA WITH
THE COLD FRONT. WENT LIKELY POPS NORTHWEST QUARTER OF THE AREA RIGHT
NEAR 12Z WITH CHANCE POPS ELSEWHERE BY THEN.
STUCK WITH A MODEL BLEND FOR TEMPERATURES WITH CLOUDS AND SOME RAIN
AROUND TONIGHT.
&&
.SHORT TERM.../MONDAY THROUGH WEDNESDAY/
ISSUED AT 250 PM EDT SUN MAY 10 2015
FOCUS IS ON RAIN/SEVERE CHANCES ON MONDAY. MODELS ARE CLOSE ENOUGH
THAT A BLEND WAS USED.
PLENTY OF UNCERTAINTY IN CONVECTIVE DEVELOPMENT ON MONDAY. FIRST
POSSIBLE SCENARIO IS THAT DYING AREA OF SHOWERS AND THUNDERSTORMS
MOVE IN DURING THE MORNING WHICH WOULD KEEP CLOUDS AROUND AND
TEMPERATURES DOWN DURING THE DAY...LOWERING THE INSTABILITY AND
THUNDERSTORM CHANCES.
SECOND SCENARIO IS ANY LINGERING CONVECTION AND ITS ASSOCIATED
CLOUDINESS DISSIPATE QUICKLY IN THE MORNING ALLOWING SOME PARTIAL
SUN AND GREATER INSTABILITY...AND THUS BETTER CHANCES FOR SEVERE.
AT ANY RATE AT LEAST SOME RAIN IS A GOOD BET AT SOME POINT ON MONDAY
AS THE STRONG COLD FRONT HAS 40-50KT 850MB WINDS AND THE RIGHT
ENTRANCE REGION OF AN UPPER JET TO AID IN THE FORCING.
THUS WENT CATEGORICAL POPS AT SOME POINT DURING THE DAY ALL AREAS ON
MONDAY. WENT HIGHER POPS EARLIER IN THE DAY WEST AND LATER IN THE
DAY EAST TO ACCOUNT FOR TIMING OF FRONT. WILL CONTINUE TO MENTION
SEVERE POTENTIAL WITH THE GOOD WIND FIELDS AND POSSIBILITY OF
GREATER INSTABILITY IF SCENARIO 2 ABOVE PANS OUT.
KEPT SOME LINGERING CHANCES FOR RAIN MONDAY EVENING ACROSS THE EAST
AS THE FRONT EXITS THE AREA. DRY AIR AND HIGH PRESSURE WILL THEN
BUILD INTO THE AREA FOR TUESDAY AND WEDNESDAY.
ON TUESDAY THERE WILL BE MORE CLOUDS NORTH AS AN UPPER LOW PASSES
ACROSS THE GREAT LAKES AND COLD AIR ALOFT MOVES IN. A DECENT WIND
FIELD ALOFT WILL PARTIALLY MIX DOWN AND PROVIDE WIND GUSTS AROUND 25
MPH DURING THE DAY.
WEDNESDAY WILL SEE FEWER CLOUDS AND WEAKER WINDS WITH HIGH PRESSURE
BUILDING IN.
WITH THE UNCERTAINTY IN CLOUDS ON MONDAY STUCK WITH A MODEL BLEND
FOR HIGH TEMPERATURES. TRENDED TOWARD THE COOLER OF THE MOS NUMBERS
FOR HIGHS ON TUESDAY WITH THE ADDITIONAL CLOUDS AND COLD AIR ALOFT.
OTHERWISE STUCK WITH A BLEND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 250 PM EDT SUN MAY 10 2015
MODELS INDICATE A PROGRESSIVE UPPER FLOW WILL OCCUR THE LATER HALF
OF THIS WEEK AND EARLY NEXT WEEK. HIGH PRESSURE ACROSS THE GREAT
LAKES WEDNESDAY NIGHT WILL MOVE TO THE NEW ENGLAND COAST BY FRIDAY.
AN UPPER RIDGE OVER THE CENTRAL U.S. EARLY ON WILL MOVE TO THE
APPALACHIANS BY SUNDAY. WEDNESDAY NIGHT AND THURSDAY SHOULD BE DRY
AS HIGH PRESSURE CONTINUES TO CONTROL OUR WEATHER. WILL MENTION
INCREASING CHANCES OF SHOWERS THURSDAY NIGHT AND THEN WILL GO WITH
CHANCE POPS REST OF THE LONG TERM.
MU CAPES ARE QUITE LOW THROUGH FRIDAY NIGHT...SO LEANED MORE TOWARDS
CHANCE OF SHOWERS RATHER THAN THUNDERSTORMS THURSDAY NIGHT AND
FRIDAY. DID MENTION A CHANCE OF THUNDER ACROSS SOUTHWEST PORTIONS
HOWEVER TO BLEND IN WITH OFFICES TO OUR SOUTHWEST. AIRMASS WILL
BECOME MORE UNSTABLE BY THE WEEKEND AS A WARM FRONT MOVES INTO OUR
AREA...SO LEANED MORE TOWARDS CHANCE OF THUNDERSTORMS OVER THE
WEEKEND. ON TEMPERATURES WENT CLOSE TO A MODEL BLEND MOST PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 11/00Z TAFS/...
ISSUED AT 713 PM EDT SUN MAY 10 2015
MAINLY VFR THROUGH THE PERIOD OUTSIDE OF ANY SHOWERS OR
THUNDERSTORMS. RAPIDLY FLUCTUATING CONDITIONS POSSIBLE IN CONVECTION.
APPEARS THAT A WEAKENING LINE OF THUNDERSTORMS MAY SWEEP ACROSS THE
SITES LATER THIS EVENING...AND WILL CARRY A VCTS MENTION FOR A TIME
TO ACCOUNT FOR THIS. HRRR NOW SUPPORTS THIS AFTER DISSIPATING THE
LINE IN EARLIER RUNS.
SHOULD BE A BREAK IN CONVECTION ASIDE FROM ISOLATED SHOWERS/STORMS
THAT ARE NEARLY IMPOSSIBLE TO TIME AND PLACE...BEFORE ANOTHER MORE
SUBSTANTIAL DISTURBANCE MOVES INTO THE AREA NEAR DAYBREAK
TOMORROW...BRINGING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS BACK
TO THE AREA. GOING TAF HANDLED THIS FAIRLY WELL.
WINDS WILL GENERALLY BE SOUTHERLY OR SOUTHWESTERLY AS HIGH AS 10 TO
15KT OVERNIGHT WITH SOME GUSTS INTO THE MID 20KT RANGE LIKELY
TOMORROW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/MK
SHORT TERM...50
LONG TERM...JH
AVIATION...NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
713 PM EDT SUN MAY 10 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 250 PM EDT SUN MAY 10 2015
A COLD FRONT WILL BRING SHOWERS AND THUNDERSTORMS TONIGHT AND
MONDAY. SOME SEVERE STORMS ARE POSSIBLE MONDAY WITH THE FRONT. DRIER
AND MUCH COOLER AIR WILL MOVE IN FOR MID WEEK. WARMER TEMPERATURES
WILL RETURN BY NEXT WEEKEND BUT SO WILL RAIN CHANCES AS A WARM FRONT
MOVES INTO THE AREA.
&&
.NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/
ISSUED AT 250 PM EDT SUN MAY 10 2015
SCATTERED CONVECTION CONTINUES TO FIRE ACROSS PORTIONS OF THE
FORECAST AREA THIS AFTERNOON AS THE TAIL OF AN UPPER WAVE REMAINS
ACROSS THE AREA. INSTABILITY WILL CONTINUE TO BUILD THIS AFTERNOON
AS SATELLITE SHOWS SOME PARTIAL CLEARING...SO WOULD NOT BE SURPRISED
TO SEE ADDITIONAL CONVECTION POP UP. WILL CONTINUE WITH CHANCE POPS.
SOME UNCERTAINTY IN RAIN CHANCES INCREASES TONIGHT AS THE EVOLUTION
OF A CONVECTIVE LINE REMAINS IN DOUBT. REMNANT OF A CONVECTIVE LINE
ACROSS MISSOURI WILL ATTEMPT TO MOVE INTO THE AREA EARLY THIS
EVENING. MAJORITY OF THE FORCING THAT INITIATED THIS LINE WILL
REMAIN WEST OF THE AREA THIS EVENING...SO A WEAKENING TREND IS
EXPECTED AS IT MOVES TOWARD AND EVENTUALLY INTO THE AREA.
THERE WILL BE INSTABILITY OVER THE AREA THOUGH SO SOME OF IT SHOULD
MAKE IT IN. WILL GO HIGHER CHANCE CATEGORY POPS THIS EVENING
WEST AND LOW EAST TO ACCOUNT FOR THE WEAKENING LINE.
OVERNIGHT MODELS TRY TO GENERATE SOME ADDITIONAL CONVECTION WITH
ANOTHER UPPER IMPULSE AHEAD OF THE COLD FRONT. THERE IS SOME
ISENTROPIC LIFT BUT BEST FORCING REMAINS JUST WEST OF THE AREA WITH
THE COLD FRONT. WENT LIKELY POPS NORTHWEST QUARTER OF THE AREA RIGHT
NEAR 12Z WITH CHANCE POPS ELSEWHERE BY THEN.
STUCK WITH A MODEL BLEND FOR TEMPERATURES WITH CLOUDS AND SOME RAIN
AROUND TONIGHT.
&&
.SHORT TERM.../MONDAY THROUGH WEDNESDAY/
ISSUED AT 250 PM EDT SUN MAY 10 2015
FOCUS IS ON RAIN/SEVERE CHANCES ON MONDAY. MODELS ARE CLOSE ENOUGH
THAT A BLEND WAS USED.
PLENTY OF UNCERTAINTY IN CONVECTIVE DEVELOPMENT ON MONDAY. FIRST
POSSIBLE SCENARIO IS THAT DYING AREA OF SHOWERS AND THUNDERSTORMS
MOVE IN DURING THE MORNING WHICH WOULD KEEP CLOUDS AROUND AND
TEMPERATURES DOWN DURING THE DAY...LOWERING THE INSTABILITY AND
THUNDERSTORM CHANCES.
SECOND SCENARIO IS ANY LINGERING CONVECTION AND ITS ASSOCIATED
CLOUDINESS DISSIPATE QUICKLY IN THE MORNING ALLOWING SOME PARTIAL
SUN AND GREATER INSTABILITY...AND THUS BETTER CHANCES FOR SEVERE.
AT ANY RATE AT LEAST SOME RAIN IS A GOOD BET AT SOME POINT ON MONDAY
AS THE STRONG COLD FRONT HAS 40-50KT 850MB WINDS AND THE RIGHT
ENTRANCE REGION OF AN UPPER JET TO AID IN THE FORCING.
THUS WENT CATEGORICAL POPS AT SOME POINT DURING THE DAY ALL AREAS ON
MONDAY. WENT HIGHER POPS EARLIER IN THE DAY WEST AND LATER IN THE
DAY EAST TO ACCOUNT FOR TIMING OF FRONT. WILL CONTINUE TO MENTION
SEVERE POTENTIAL WITH THE GOOD WIND FIELDS AND POSSIBILITY OF
GREATER INSTABILITY IF SCENARIO 2 ABOVE PANS OUT.
KEPT SOME LINGERING CHANCES FOR RAIN MONDAY EVENING ACROSS THE EAST
AS THE FRONT EXITS THE AREA. DRY AIR AND HIGH PRESSURE WILL THEN
BUILD INTO THE AREA FOR TUESDAY AND WEDNESDAY.
ON TUESDAY THERE WILL BE MORE CLOUDS NORTH AS AN UPPER LOW PASSES
ACROSS THE GREAT LAKES AND COLD AIR ALOFT MOVES IN. A DECENT WIND
FIELD ALOFT WILL PARTIALLY MIX DOWN AND PROVIDE WIND GUSTS AROUND 25
MPH DURING THE DAY.
WEDNESDAY WILL SEE FEWER CLOUDS AND WEAKER WINDS WITH HIGH PRESSURE
BUILDING IN.
WITH THE UNCERTAINTY IN CLOUDS ON MONDAY STUCK WITH A MODEL BLEND
FOR HIGH TEMPERATURES. TRENDED TOWARD THE COOLER OF THE MOS NUMBERS
FOR HIGHS ON TUESDAY WITH THE ADDITIONAL CLOUDS AND COLD AIR ALOFT.
OTHERWISE STUCK WITH A BLEND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 250 PM EDT SUN MAY 10 2015
MODELS INDICATE A PROGRESSIVE UPPER FLOW WILL OCCUR THE LATER HALF
OF THIS WEEK AND EARLY NEXT WEEK. HIGH PRESSURE ACROSS THE GREAT
LAKES WEDNESDAY NIGHT WILL MOVE TO THE NEW ENGLAND COAST BY FRIDAY.
AN UPPER RIDGE OVER THE CENTRAL U.S. EARLY ON WILL MOVE TO THE
APPALACHIANS BY SUNDAY. WEDNESDAY NIGHT AND THURSDAY SHOULD BE DRY
AS HIGH PRESSURE CONTINUES TO CONTROL OUR WEATHER. WILL MENTION
INCREASING CHANCES OF SHOWERS THURSDAY NIGHT AND THEN WILL GO WITH
CHANCE POPS REST OF THE LONG TERM.
MU CAPES ARE QUITE LOW THROUGH FRIDAY NIGHT...SO LEANED MORE TOWARDS
CHANCE OF SHOWERS RATHER THAN THUNDERSTORMS THURSDAY NIGHT AND
FRIDAY. DID MENTION A CHANCE OF THUNDER ACROSS SOUTHWEST PORTIONS
HOWEVER TO BLEND IN WITH OFFICES TO OUR SOUTHWEST. AIRMASS WILL
BECOME MORE UNSTABLE BY THE WEEKEND AS A WARM FRONT MOVES INTO OUR
AREA...SO LEANED MORE TOWARDS CHANCE OF THUNDERSTORMS OVER THE
WEEKEND. ON TEMPERATURES WENT CLOSE TO A MODEL BLEND MOST PERIODS.
&&
.AVIATION /DISCUSSION FOR THE 11/00Z TAFS/...
ISSUED AT 713 PM EDT SUN MAY 10 2015
MAINLY VFR THROUGH THE PERIOD OUTSIDE OF ANY SHOWERS OR
THUNDERSTORMS. RAPIDLY FLUCTUATING CONDITIONS POSSIBLE IN CONVECTION.
APPEARS THAT A WEAKENING LINE OF THUNDERSTORMS MAY SWEEP ACROSS THE
SITES LATER THIS EVENING...AND WILL CARRY A VCTS MENTION FOR A TIME
TO ACCOUNT FOR THIS. HRRR NOW SUPPORTS THIS AFTER DISSIPATING THE
LINE IN EARLIER RUNS.
SHOULD BE A BREAK IN CONVECTION ASIDE FROM ISOLATED SHOWERS/STORMS
THAT ARE NEARLY IMPOSSIBLE TO TIME AND PLACE...BEFORE ANOTHER MORE
SUBSTANTIAL DISTURBANCE MOVES INTO THE AREA NEAR DAYBREAK
TOMORROW...BRINGING MORE WIDESPREAD SHOWERS AND THUNDERSTORMS BACK
TO THE AREA. GOING TAF HANDLED THIS FAIRLY WELL.
WINDS WILL GENERALLY BE SOUTHERLY OR SOUTHWESTERLY AS HIGH AS 10 TO
15KT OVERNIGHT WITH SOME GUSTS INTO THE MID 20KT RANGE LIKELY
TOMORROW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM...JH
AVIATION...NIELD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
913 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 847 PM CDT SUN MAY 10 2015
ANTICIPATE AT LEAST SCATTERED STORMS DEVELOPING AND/OR MOVING OVER
PORTIONS OF THE CWA REST OF TONIGHT UNTIL THE COLD FRONT PASSES
LATE. AS THE WARM FRONT CURRENTLY NEAR HWY 34 CORRIDOR LIFTS NORTH
OVERNIGHT WILL LIKELY SEE A WINDOW OF SURFACE BASED OPPORTUNITY
DEVELOP AS CWA THRUST IN WARM SECTOR AHEAD OF APPROACHING COLD
FRONT. STRENGTHENING MID/UPPER LEVEL WIND FIELDS OVERSPREADING
CWA ALONG WITH 0-6KM SHEAR OF 40+ KTS WOULD SUPPORT AT LEAST SOME
RISK OF SEVERE DESPITE THE NON-FAVORABLE TIMING AND CANNOT TOTALLY
DISCOUNT ISOLATED MARGINAL SEVERE WIND POSSIBLE IN THE STRONGEST
STORMS. ALSO...MONITORING TRENDS FOR POSSIBLY RAISING POPS OVER
THE SOUTHEAST THIRD OR SO OF CWA LATE TONIGHT INTO EARLY MONDAY AM
WITH LATEST FEW RUNS OF HRRR AND RAP MODELS SHOWING UPPER LEVEL
ENERGY AND ATTENDANT PCPN SHIELD OVER OK INTO NORTHWEST AR MOVING
NORTHEAST AND PHASING WITH COLD FRONT AS IT MOVES EAST OF THE
MISSISSIPPI RIVER.
WILL HAVE UPDATED ZFP/PFM OUT SOON.
&&
.SYNOPSIS...
ISSUED AT 240 PM CDT SUN MAY 10 2015
ANALYSIS AT 2 PM CDT SHOWS COOL AND CLOUDY EAST WINDS OVER ALL BUT
FAR SOUTH SECTIONS OF AREA. A BAND OF NON-SEVERE SHOWERS AND
THUNDERSTORMS IN MISSOURI TO PASS ACROSS THE AREA BETWEEN 10/21Z
AND 11/03Z. UPSTREAM ENERGY SUGGEST SHOWERS AND STORMS POSSIBLE
UNTIL EARLY MONDAY WITH SEVERE RISK LOW DUE TO LIMITED INSTABILITY
AND MARGINAL SHEAR AND FORCING WITH MOSTLY LIGHT TO MODERATE RAIN
AMOUNTS AS BEST FORCING TO OUR WEST AND SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 240 PM CDT SUN MAY 10 2015
SHORT TERM FORECAST CONFIDENCE ASSESSMENT...FAIR OR AVERAGE WITH COVERAGE
AND AMOUNTS OF NON-SEVERE STORMS THROUGH THIS EVENING WITH MOSTLY SHOWERS
INTO EARLY MONDAY. RAIN TOTALS MOSTLY QUARTER TO THREE QUARTERS AT MOST
WITH MANY LOCATIONS PICKING UP LESS THAN A QUARTER INCH.
TONIGHT...MOST OF PRECIPITATION TO FALL BY MIDNIGHT ALL BUT EAST AND
SOUTHEAST SECTIONS WITH AGAIN ONE QUARTER TO THREE QUARTERS OF AN INCH
THE MOST COMMON. LOWS LOWER 50S FAR WEST WITH CLEARING AND COOLER AIR
MOVING AND LOWER 60S EAST. LIGHT SOUTHERLY WINDS OF 5 TO 15 KTS EXCEPT
SOME GUSTS OVER 25 KTS POSSIBLE IN THE STRONGEST STORMS.
MONDAY...SHOWERS MAY CONTINUE INTO THE MID DAY HOURS OVER MOSTLY EAST
SECTIONS WITH CLEARING OVER MOST TO ALL THE AREA BY MID TO LATE AFTERNOON.
GUSTY WEST TO SOUTHWEST WINDS OF 10 TO 20+ KTS BEHIND THE FRONT WITH
HIGHS LOWER 60S WEST TO AROUND 70 DEGREES IN THE EAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CDT SUN MAY 10 2015
FORECAST FOCUS ON COOL WEATHER FOR THE FIRST HALF OF THE NEW WORK
WEEK THEN WARMER WITH CHANCES FOR THUNDERSTORMS LATER IN THE WEEK
AND INTO NEXT WEEKEND.
MONDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE WILL BE TRACKING
ACROSS THE NORTHERN GREAT LAKES WITH A NORTHWEST FLOW ALOFT IN THE
WAKE OF THE SYSTEM. THIS WILL SEND BELOW NORMAL TEMPERATURES ALONG
WITH DRY WEATHER INTO THE DVN CWA. MAXIMUM TEMPERATURES ARE EXPECTED
TO BE IN THE 60S WITH LOWS MAINLY IN THE 40S. THE COOLEST NIGHT
LOOKS TO BE TUESDAY NIGHT WHEN A HIGH PRESSURE RIDGE WILL SETTLE
OVER THE AREA...BRINGING CLEAR SKIES AND LIGHT WINDS. THIS SHOULD
ALLOW FOR SOME AREAS TO DIP INTO THE MID TO UPPER 30S ESPECIALLY
ALONG HIGHWAY 20. WILL NEED TO MONITOR FOR THE POTENTIAL FOR FROST.
THURSDAY THROUGH SUNDAY...OPERATIONAL MODELS TRANSITION TO A
SOUTHWEST FLOW ALOFT ONCE AGAIN...AS A MAJOR UPPER LEVEL TROUGH
PUSHES SLOWLY EASTWARD INTO THE ROCKIES BY LATE IN THE WEEK. THIS
SYSTEM THEN LIFTS OUT INTO THE PLAINS NEXT WEEKEND. THIS WILL SET UP
THE CWA FOR PERIODS OF SHOWERS AND THUNDERSTORMS BUT TIMING OF THESE
IS DIFFICULT THIS FAR OUT IN TIME. FOR NOW WILL HAVE CHANCE POPS
EACH DAY BUT THERE WILL ALSO BE DRY PERIODS. WARMER TEMPERATURES CAN
BE EXPECTED AND BY THE TIME WE GET TO SUNDAY SOME LOCATIONS SHOULD
BE PUSHING ABOVE THE 80 DEGREE MARK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 644 PM CDT SUN MAY 10 2015
AN AREA OF SHOWERS AND STORMS WILL LIFT THROUGH EAST CENTRAL AND
NORTHEAST IA NEXT 1-2 HOURS IMPACTING CID...DBQ AND MLI TERMINALS
WITH MAINLY MVFR TO LOCAL IFR CONDITIONS. MEANWHILE... VFR
CONDITIONS WILL START THE TAF CYCLE AT BRL. ADDITIONAL SHOWERS AND
SCATTERED STORMS WILL BE POSSIBLE LATE THIS EVENING AND OVERNIGHT
UNTIL A COLD FRONT PASSES. ANTICIPATE REDEVELOPMENT OF IFR TO MVFR
CONDITIONS AHEAD OF THE COLD FRONT. SKIES WILL THEN CLEAR WITH
VFR CONDITIONS AND WEST TO SOUTHWEST WINDS OF 10-20 KTS AS COOLER
AND DRIER AIR MOVES IN TOWARD DAYBREAK INTO EARLY MONDAY AM. WOULD
ANTICIPATE SOME SCT-BKN STRATOCU WITH MVFR TO VFR BASES BY MID
MONDAY AM THROUGH AFTN ALONG WITH GUSTY WESTERLY WINDS AOA 10 KTS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...05
AREA FORECAST DISCUSSION
NWS DES MOINES IA
400 PM CDT SAT MAY 9 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
QUIET FOR THE REST OF SATURDAY AND THEN STORM CHANCES ENTER THE FCST
LATE IN THIS SHORT TERM PERIOD. A POCKET OF DRIER AIR HAS BEEN IN
PLACE MOST OF SATURDAY AFTERNOON ACROSS THE CWA ALLOWING FOR
SUNSHINE TO PUNCH THROUGH ACROSS THE CENTRAL TO NORTHERN PARTS OF
OUR CWA.
THE LARGE AREA OF LOW PRESSURE WE HAVE BEEN TALKING ABOUT
FOR THE PAST FEW DAYS HAS REACHED THE FOUR CORNERS REGION OF THE
CONUS. THIS LOW IS SLATED TO BE LOCATED OVER WESTERN NEBRASKA BY 12Z
SUN. THE NAM IS A SLIGHT OUTLIER...KEEPING THIS SYSTEM SLOWER AND
FURTHER TO THE SOUTH THAN THE REST OG GUIDANCE. THE GFS IS THE
FASTEST. LEANED TOWARDS THE EURO...WHICH IS IN THE MIDDLE...FOR
TIMING. FOR LOW LEVEL MOISTURE INIT...USUAL MODEL BIASES IN PLACE.
THE NAM IS THE MOST MOIST...WHILE THE GFS IS OVERLY DRY. LEANED
TOWARDS EURO ONCE AGAIN.
AHEAD OF THIS AREA OF LOW PRESSURE...A WARM FRONT WILL BE PASSING
THROUGH OUR CWA FROM SW TO NE. ALL MODELS SHOW THE GULF IS WIDE OPEN
FOR MOISTURE TRANSPORT VIA THE LLJ...THE NOSE OF WHICH WILL BE ALONG
THE WESTERN/CENTRAL PART OF OUR CWA AT 12Z SUN. REGARDING THE SEVERE
WEATHER POTENTIAL...THE RAP SHOWS 0-1KM BULK SHEAR VALUES IN THE 20
TO 25KT RANGE...HELICITY IN THE 200 TO 400 RANGE AND LOW ENOUGH LCL
HEIGHTS TO SUGGEST TORNADOES MAY BE A SEVERE MODE THREAT EARLY ON.
DCAPE VALUES ARE ALSO HIGH EARLY ON...SO DAMAGING WINDS IS ALSO A
THREAT. LOCATION-WISE...THIS WILL MAINLY BE IN THE WESTERN/SW CWA AT
12Z. THE EVOLUTION OF SUNDAY/S SEVERE WEATHER WILL BE HANDLED IN THE
LONG TERM.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
ISSUED AT 355 PM CDT SAT MAY 9 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SEVERE WEATHER POTENTIAL FOR
SUNDAY INTO SUNDAY NIGHT. THE REMAINDER OF THE FORECAST TIME FRAME
REMAINS RELATIVELY QUIET UNTIL LATE IN THE WORK WEEK.
SUNDAY INTO SUNDAY NIGHT...POTENTIAL EXISTS FOR AT LEAST TWO
ROUNDS OF SEVERE WEATHER ON MOTHERS DAY...WITH THE MORNING
CONVECTION SURGING NORTHWARD WITH THE WARM FRONT THROUGH 15Z AND
THEN THE DIURNALLY DRIVEN CONVECTION IN THE AFTERNOON ALONG THE
DRY LINE BY THE LATE AFTERNOON/EARLY EVENING. LEANED TOWARD THE
NAM12/ARWWRF FOR TIMING OF POPS SUNDAY INTO SUNDAY NIGHT EVEN
THOUGH MODELS ARE IN FAIRLY GOOD AGREEMENT WRT TO SURFACE LOW
TRACK AND TIMING OF COLD FROPA SUNDAY EVENING. THIS RESULTED IN
DELAYING THE AFTERNOON CONVECTION SLIGHTLY AS INITIATION LOOKS TO
BE AFTER 20Z SUNDAY OVER WESTERN PORTIONS OF THE FORECAST AREA.
THE WARM FRONT LOOKS TO SURGE NORTHWARD TO THE IOWA/MINNESOTA
BORDER BY AROUND 00Z MONDAY WITH THE SURFACE LOW CENTERED OVER
FAR NORTHWEST CORNER OF IOWA AND FAR SOUTHEAST SOUTH DAKOTA. THE
STRONGER AND DEEPER FORCING FOR ASCENT IS IN THIS LOCATION BUT
QUESTIONABLE WHETHER SURFACE INSTABILITY RECOVERS ENOUGH TO
SUPPORT LOW-LIVED TORNADIC SUPERCELLS. HOWEVER...ENOUGH ELEVATED
MUCAPE PRESENT COMBINED WITH STRONG LOW LEVEL SHEAR AND VORTICITY
WITHIN THE VICINITY OF THE WARM FRONT LOOKS TO COUNTERACT THE LACK
OF SURFACE INSTABILITY AND CERTAINLY PROVIDE A DECENT THREAT FOR
TORNADOES AND LARGE HAIL OVER WEST-CENTRAL TO NORTH-CENTRAL IOWA
TOMORROW AFTERNOON. DEEP LAYER SHEAR FROM 50 TO NEAR 70 KNOTS
PLENTY STRONG ENOUGH TO KEEP CONVECTION THROUGH THE EVENING SUNDAY
AS THE COLD FRONT PUSHES ACROSS IOWA. SEVERE POTENTIAL EXISTS
ALONG THE COLD FRONT WITH STRAIGHT-LINE WINDS THROUGH ROUGHLY 03Z
MONDAY BEFORE ENVIRONMENT BECOMES LESS FAVORABLE. THINKING ANY
SUPERCELLS THAT DEVELOP LATE TOMORROW AFTERNOON WILL MORPH INTO A
QLCS TYPE STRUCTURE WITH THE ADVANCEMENT OF THE COLD FRONT...WHICH
WOULD KEEP THE ROUNDS OF SEVERE WEATHER AT ONLY TWO. IF CONVECTION
PUSHES NORTH INTO MINNESOTA THEN A THIRD ROUND ALONG THE COLD
FRONT SEEMS FEASIBLE TOMORROW EVENING WITHIN THE DMX CWA.
MONDAY THROUGH WEDNESDAY...STRONG CAA DEVELOPS ON MONDAY INTO
MONDAY NIGHT AND MAY SEE A FEW SHOWERS ACROSS THE NORTH WITH
SOME WRAP-AROUND MOISTURE FROM THE SURFACE LOW. OTHERWISE...COOL
AND DRY CONDITIONS THROUGH WEDNESDAY.
THURSDAY INTO SATURDAY...LARGE UPPER LEVEL RIDGE BEGINS TO BREAK
DOWN WITH A FAIRLY STRONG VORT MAX EJECTING OUT OF THE SOUTHERN
ROCKIES THURSDAY. UNCERTAINTY IN TIMING WITH THE ECMWF ROUGHLY 12
HOURS QUICKER THAN THE GFS. BY THE END OF THE WORK WEEK AND INTO
NEXT WEEKEND...THE REGION IS PLACED BACK INTO SOUTHWEST FLOW ALOFT
AND EXTENDED MODELS HAVE MULTIPLE SHORTWAVES TO AFFECT THE FORECAST
AREA.
&&
.AVIATION...09/18Z
ISSUED AT 1240 PM CDT SAT MAY 9 2015
VFR AND MVFR CATEGORIES IN THIS PACKAGE. BIGGEST FORECAST ISSUE
WILL BE ARRIVAL OF A LINE OF SUNDAY MORNING STORMS. SEVERE WEATHER
IS POSSIBLE. IF ANYTHING...ARRIVAL OF STORMS MAY NEED TO BE
PUSHED BACK A FEW HOURS. ADDITIONALLY...SOME OF THE STORMS MAY BE
INTENSE...ESPECIALLY OVER KFOD...AND MAY CAUSE IFR CEILINGS. LEFT
CB WORDING OUT OF KALO AND KMCW TAFS AS STORMS MAY BE WEAKENED BY
THE TIME THEY REACH THOSE SITES. THERE WILL ALSO LIKELY BE GUSTY
WINDS WITH THE MORNING STORMS...POSSIBLY REACHING 30 TO 40 KTS
WITH ANY STRONGER STORMS. ANOTHER ROUND OF STRONG TO SEVERE STORMS
LOOKS POSSIBLE HEADING INTO SUNDAY AFTERNOON/EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...KOTENBERG
LONG TERM...PODRAZIK
AVIATION...KOTENBERG
AREA FORECAST DISCUSSION
NWS TOPEKA KS
326 PM CDT Sat May 9 2015
.SHORT TERM...(This Evening through Sunday)
Issued at 322 PM CDT SAT MAY 9 2015
An intense upper level trough was located across northwest NM. An 80
KT H5 jet max was lifting northeast across west TX into southwest
KS. A dryline was sharpening up from southeast CO, south-southeast
across the eastern TX PNHDL, then south into the hill country of
west central TX. The center of a lee cyclone, north of TAD. The warm
front extended east south-southeast from the lee cyclone, across
southwest KS, then east along the KS and OK border. A band of
elevated thunderstorms that formed across southeast CO and the TX
PNHDL earlier this morning continues to slowly move northeast across
central and south central KS. The area of elevated thunderstorms
were beginning to weaken as they move northeast into a more stable
airmass across eastern KS. An MCS was forming across central OK and
will move east-northeast across northeast OK into southwest MO.
The CWA will see a gradual increase in isolated to scattered shower
and thunderstorms late this afternoon, but with MUCAPES only 500 to
1000 J/KG these storms will not become severe this afternoon. As the
warm front begins to push north, the isentropic lift will begin to
weaken and we may see a break in the shower and thunderstorms
activity through the mid evening hours. Farther west, the atmosphere
is beginning to recover from the morning convection across the
eastern TX PNHDL, eastern CO and western KS. As the upper low over
northwest NM lifts northeast into east-central CO, numerous
thunderstorms should develop along the dryline as it begins to push
northeast across the eastern TX PNHDL into southwest KS and east
central CO. Intense upper level ascent ahead of the lifting upper
low will allow scattered supercell thunderstorms across western KS
to congeal into a QLCS or an MCS through the evening hours across
western KS. This storm complex will lift northeast across north
central KS late this evening and through the early morning hours of
Sunday. If a complex of thunderstorms develop the primary hazards
will be large hail, damaging winds and heavy rain. The meso-scale
models such as the RAP and WRF move the more intense portions of the
MCS north-northeast into southern NE just west of the CWA. Though,
there may be enough ascent that scattered thunderstorms will develop
south-southeast of this complex of thunderstorms. The primary hazard
of any severe thunderstorms across the CWA later Tonight will be
large hail, damaging wind gusts and heavy rainfall. The vertical
wind shear and MUCAPE do increase later Tonight, thus if a supercell
thunderstorm develops the boundary layer may not be decoupled enough
to prevent isolated tornadoes. However, at this time the better
chances for tornadic supercells will be this evening across western
KS.
Due to the uncertainty in the intensity and areal extent of wide
spread deep moist convection, I will not be issuing a flash flood
watch for the CWA. There is a chance for locally heavy rainfall with
any convective complex that develops. The isolated to scattered
thunderstorms later Tonight will move quickly to the northeast, so
expect only brief heavy rainfall. The better chances for heavy
rainfall will be associated with MCS`s that are forecasted to move
southeast and northwest of the CWA.
Sunday, there may be a few morning storms across the eastern
counties of the CWA. The upper low will begin to slowly fill as it
lifts northeast-northeast into western NE during the day. A strong
H5 jet max of 50 to 60 KTS will over spread eastern KS through the
afternoon hours. A cold front will quickly occlude the dryline
across central KS during the mid and late morning hours and the cold
front will push east across the western half of the CWA during the
early Afternoon hours. The numerical models all show the 850mb winds
slowly veering to the southwest ahead of the surface front. However,
the numerical models forecast southerly or even southeasterly
surface wind ahead of the surface front. The deepest gulf moisture
may get shunted eastward across MO into eastern IA but several
mesoscale models are showing 10 to 12 DEG Td at 850mb remaining
ahead of the surface front. There should be enough deep moisture and
instability for scattered thunderstorms to begin to develop along
the surface cold front by 20Z. The front should extend roughly from
a Seneca to Manhattan to Council Grove line by 3 PM. Thunderstorms
that develop will rapidly become severe given MLCAPES of 1500 to
2500 J/KG and SFC to 6KM effective shear of 50 to 60 KTS. Even
though 850mb winds begin to veer slightly the surface winds may
remain back. Therefore as storms first form they may be isolated to
scattered supercells before congealing into a squall line which will
then push east across northeast and east central KS during the late
afternoon hours. The 0-1 SRH of 150 to 250 J/KG may support any
discrete supercell to produce isolated tornadoes. Once the isolated
to scattered supercells merge into a squall line then the primary
hazards will be damaging winds gusts, large hail and heavy rainfall.
The line will move fairly fast across the eastern counties of the
CWA and begin to weaken after 6 PM due to the loss of surface
heating. Highs just behind the surface front across the central
counties of the CWA may reach to around 80 degrees, with most other
areas getting into the mid to upper 70s.
.LONG TERM...(Sunday Night through Saturday)
Issued at 322 PM CDT SAT MAY 9 2015
Sunday Night through Monday Night ...
By Sunday evening, models are in fairly good agreement with the
surface and mid-level patterns. A closed mid-level low should be
centered over the northern High Plains with the deep trough
stretching all the way southward toward the U.S./Mexico border. At
the surface, the center of low pressure should be focused across
northeast Nebraska with the associated cold front extending
southward and essentially bisecting the forecast area (i.e.,
stretching from Marysville to Manhattan to Herington by early
evening). This front placement is a bit further west than what
models were suggesting yesterday. Model soundings show little to no
inhibition in place across the area by late afternoon/early evening.
Expect decent advection of warm, moist air ahead of this boundary
from the breezy southerly winds, resulting in a decent set-up for
some strong to severe thunderstorms late afternoon into the evening
hours. Models suggest that isolated storms should develop along and
ahead of the cold front by late afternoon/early evening and quickly
congeal into a line of storms as the wind profiles look to prevail
out of the southwest. With a north/south oriented boundary, this
southwesterly flow should help to advance this line of storms fairly
quickly eastward across eastern KS with most of the forecast area
dry by midnight. Increasing low-level cloud cover combined with
little inhibition may result in slightly lower CAPE values upwards
of 1500-1800J/kg. Wind profiles show fairly unidirectional winds out
of the southwest with a 60-70kt 500mb jet, however there are some
discrepancies with regards to how much winds will veer in the lowest
2km of the atmosphere. As a result, there is a notable range amongst
the models in 0-1km helicity values across far eastern Kansas. LCL
values should be fairly low at around 3000ft or less, but the lapse
rates do not look that great. With these conditions and model
discrepancies in mind, confidence is low in the tornado threat
across eastern Kansas Sunday evening however an isolated tornado or
two still cannot be ruled out. Expect upwards of 50-60kts of 0-6km
shear, so combined with the modest instability the primary severe
threats look to be large hail and strong winds. Some locally heavy
rainfall will also be possible, which may potentially result in some
localized flash flooding and/or river flooding as some locations
have already received a few inches of rain this week. However, with
1-hr and 3-hr flash flood guidance near 2 inches, do not expect
widespread flooding concerns with these fast-moving storms.
Winds will slowly veer toward the west overnight into Monday morning
with clearing skies. As a result, decent radiational cooling should
help to drop low temperatures into the 40s. The mid-level trough
will lift northward out of the area through the day on Monday with
surface high pressure advancing into the High Plains behind this
exiting system. West-northwesterly surface winds will usher cooler
air into the region, keeping Monday high temperatures below normal
in the low/mid 60s. These cool conditions and mostly clear skies
will persist into Monday night with even cooler overnight low
temperatures in the upper 30s to mid 40s.
Tuesday through Saturday...
Tuesday will have mostly sunny skies and highs in the upper 60s,
with lows dropping into the upper 40s Tuesday night. The surface
high pressure aiding in these mild conditions will move southeast of
the area late evening, allowing winds to veer to the south by Wednesday
morning. This warm air advection will push highs into the lower
70s, before another system pushes into the area bringing chances for
precipitation every day for the rest of the period.
Models are still inconsistent with the handling this next system,
but agree with the previous forecast that the ECMWF solution seems
more reasonable. An upper-level wave will move NE into the central
plains by late Thursday bringing the best chances for thunderstorms
Wednesday night though Thursday night. Severe potential is still
low as the best CAPE/shear seems to be south or west of our area,
depending on the model. From here, thunderstorm chances remain until
Saturday, but confidence in timing and the overall pattern are
low.
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1240 PM CDT SAT MAY 9 2015
Stratus with MVFR ceilings will gradually rise to VFR ceilings
later this afternoon. Scattered thunderstorms will move into the
terminals later this afternoon and evening. there may be a
several hour break before more scattered thunderstorms move into
the terminals after 6Z SUN. Stratus ceilings will lower to MVFR
category overnight and remain that way through the morning hours
of SUN.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...Heller/Hennecke
AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1224 PM CDT SAT MAY 9 2015
...UPDATED AVIATION SECTION...
.SYNOPSIS...
ISSUED AT 1120 AM CDT SAT MAY 9 2015
A STRONG UPPER LEVEL LOW CURRENTLY OVER THE FOUR CORNER`S REGION
WILL CONTINUE TO MOVE NORTHEAST INTO COLORADO THIS AFTERNOON INTO
THE EARLY EVENING HOURS. A 90+ KNOT 250 MB JET WILL EXTEND AROUND
THE PERIPHERY OF THIS LOW STRETCHING FROM SOUTHERN NEW MEXICO,
NORTHWARD THROUGH THE NM/TX BORDER AND ALONG THE KS/CO BORDER. LOW
TO MID LEVELS OF THE ATMOSPHERE ARE CURRENTLY SATURATED ALLOWING
MOSTLY CLOUDY SKIES TO BE OBSERVED ACROSS A MAJORITY OF THE CWA.
TOWARDS THE SURFACE, AN AREA OF LOW PRESSURE WILL BE LOCATED
ACROSS EASTERN COLORADO WITH AN ASSOCIATED WARM FRONT EXTENDING
EASTWARD THROUGH KANSAS. THIS WARM FRONT LOOKS TO SHIFT NORTHWARD
THIS AFTERNOON AND ALONG THE KS/NE BORDER BY THIS EVENING. A
DRYLINE WILL BE LOCATED ALONG THE KS/CO BORDER EARLY THIS
AFTERNOON SLIDING EASTWARD AS THE DAY PROGRESSES. MEANWHILE, MID
LEVELS OF THE ATMOSPHERE DRY OUT ACROSS FAR WESTERN KANSAS THIS
AFTERNOON LEADING TO BREAKS IN THE CLOUDS ALLOWING SUN TO
INFILTRATE TO THE SURFACE. WARMING TEMPERATURES ALONG WITH AMPLE
MOISTURE AND LIFT AT THE SURFACE WILL DESTABILIZE WESTERN KANSAS
WITH STRONG TO SEVERE THUNDERSTORMS EXPECTED LATE THIS AFTERNOON
INTO THE EVENING HOURS. PLEASE KEEP YOUR EYES ON THE WEATHER THIS
AFTERNOON INTO EVENING AND COME TO OUR WEBSITE, FACEBOOK, OR
TWITTER PAGE FOR THE MOST CURRENT SEVERE WEATHER INFORMATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM CDT SAT MAY 9 2015
...SIGNIFICANT SEVERE WEATHER EVENT LIKELY...
ALL THE FOCUS IN THE SHORT TERM IS HOW THE CONVECTIVE PICTURE
TODAY WILL EVOLVE AND WHAT WILL THE IMPACTS BE. IT SHOULD BE NOTED
THAT THERE IS STILL LARGE UNCERTAINTY IN HOW STORMS WILL EVOLVE,
SO KEEP UPDATED AS THE FORECAST IS ADJUSTED THROUGH THE DAY. THIS
UNCERTAINTY IS REFLECTED IN THE VARIOUS MESOSCALE MODELS THAT ARE
ALL OFFERING DIFFERENT SOLUTIONS. HAVE PUT THE THE HRRR ON THE
BACK BURNER BECAUSE THIS MODEL HAS BEEN DOING POORLY RECENTLY
(I.E. CONVECTION ACROSS OKLAHOMA/TEXAS LAST NIGHT). THE
OPERATIONAL NAM HAS BEEN DOING A LITTLE BETTER, SO INFLUENCE FROM
THIS MODEL WAS USED. PURELY SUBJECTIVELY, THE WRF-ARW HAS BEEN
DOING THE BEST AND POP AND MESOSCALE GUIDANCE WAS HEAVILY BIASED
TOWARDS THIS MESOSCALE MODEL.
THERE WILL BE TWO ROUNDS OF CONVECTION FOR TODAY. THE FIRST ROUND
WILL BE THIS MORNING AS CONVECTION MOVES FROM THE PANHANDLES
NORTHWARD TO SOUTHWEST KANSAS. THIS ACTIVITY IS ASSOCIATED WITH
WARM AIR ADVECTION AND A VORTMAX SWING THROUGH AHEAD OF THE MAIN
SYNOPTIC TROUGH. THUNDERSTORMS THIS MORNING WILL BE STRONG TO
PERHAPS MARGINALLY SEVERE. THE MAIN SHOW IS THIS AFTERNOON AND
EVENING AS THE SYNOPTIC LOW EJECTS AND THE NOSE OF A 80-90 KT
250-HPA JET MOVES CLOSER. INTENSE LEE CYCLOGENESIS IS EXPECTED
WITH A STRONG WIND FIELD AND RESULTANT SHEAR DEVELOPING ACROSS WESTERN
KANSAS THROUGH THE DAY. FROM THE WRF-ARW, THINK STORMS WILL REFIRE
ALONG THE DRYLINE DURING THE EARLY AFTERNOON ROUGHLY FROM COLBY
SOUTHEAST TO LIBERAL. THERE ARE A FEW QUESTIONS THOUGH ABOUT THIS
SECOND ROUND. 1) WILL CONVECTION THIS MORNING IMPEDE MOISTURE
RETURN BY THE AFTERNOON? 2) HOW MUCH RECOVERY WILL THERE BE IN THE
WAKE OF THE FIRST ROUND OF STORMS. MESOSCALE MODELS DO SUGGEST
SUFFICIENT INSTABILITY DEVELOPING BY THE AFTERNOON (2500 J/KG
SBCAPE). 3) SOMETHING THAT I NOTICED SEVERAL DAYS AGO, FORECAST
SKEW-T/LOG-P`S SHOW BACKING OF UPPER LEVEL WINDS. THIS COULD
ENCOURAGE HP SUPERCELL (MESSY) STORM TYPE. THERE IS ENOUGH
ORTHOGONALITY THOUGH BETWEEN THE DRYLINE AND 850-300 HPA FLOW THAT
I EXPECT AT LEAST DISCRETE HP SUPERCELLS. 4) WILL THE WRF-ARW
VERIFY OR WILL IT BE WRONG LIKE THE HRRR WAS LAST NIGHT. SO,
SEVERAL QUESTIONS THAT WILL NEED TO BE ANSWERED. THE MODERATE RISK
FROM SPC ALSO HIGHLIGHTS THE UNCERTAINTY THAT I HAVE. ANYWAY, THE
ENVIRONMENT IS PRIMED FOR SIGNIFICANT SEVERE WEATHER. LARGE HAIL
(2-3") LOOKS LIKELY FROM THE LARGE HAIL PARAMETER. FOR TORNADOES,
SIGNIFICANT TORNADO PARAMETER OF 5-10, 250-300 M2S2 SFC-3 KM SRH,
20-30 KT OF 0-1 BULK SHEAR, AND A LOOPING HODOGRAPHS CLEARLY GIVEN
CREDENCE FOR STRONG TORNADOES (PERHAPS A VIOLENT TORNADO SHOULD
MESOSCALE STORM DETAILS PLAY OUT CORRECTLY/OFB LAID OUT). THE
WRF-ARW ALSO IS FORECASTING UPDRAFT HELICITY, SO CLEARLY THE MODEL
IS TRYING TO DEPICT ROTATING STORMS (SUPERCELLS). WITH A
COMBINATION OF CAPE AND LOW LEVEL SHEAR, THINK THE BEST AREA FROM
TORNADOES IS PROBABLY IN THE GARDEN CITY, MEADE, DODGE CITY, SCOTT
CITY AREA THIS AFTERNOON. AGAIN, YOU CAN HAVE ALL THE PERFECT
PARAMETERS, BUT IF INSTABILITY IS LACKING DUE TO LINGERING CLOUD
COVER FROM AM STORMS... THEN NONE OF THIS WILL MATTER AND THE
SEVERE THREAT WILL BE MORE SUBDUED. WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT. LASTLY, SEE THE YOUTUBE VIDEO THAT WAS PUT UP THIS
MORNING FOR A GRAPHIC REPRESENTATION OF ALL THIS TECHNICAL TALK
ABOVE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 257 AM CDT SAT MAY 9 2015
BY SUNDAY MORNING, THE UPPER LOW WILL BE OVER THE NORTHEAST CORNER
OF COLORADO AND WILL BE LIFTING INTO THE EASTERN DAKOTAS BY SUNDAY
EVENING. THE ATTENDANT SURFACE LOW WILL ALSO LIFT NORTHEAST OUT OF
THE REGION. EARLY ON, SOME WRAPAROUND SHOWERS WILL BE POSSIBLE OVER
WEST CENTRAL KANSAS BUT THESE SHOULD BE ENDING FAIRLY QUICKLY AS THE
UPPER LOW MOVES OUT. THROUGH THE REMAINDER OF THE DAY, WESTERN
KANSAS WILL BE UNDER CYCLONIC MID LEVEL FLOW IN THE WAKE OF THE
UPPER LOW. COOLER, DRIER AIR WILL BE SPREADING INTO THE AREA BUT WE
SHOULD SEE PERIODS OF CLOUDS ALONG WITH BREEZY CONDITIONS ESPECIALLY
WITH MAX HEATING DURING THE DAY. LOW LEVEL COLD ADVECTION CONTINUES
INTO SUNDAY NIGHT WHICH SHOULD KEEP WINDS UP SOMEWHAT ACROSS THE
AREA. TEMPERATURES SHOULD FALL INTO THE MID 30S OVER WESTERN
SECTIONS OF THE AREA...ALONG THE COLORADO BORDER. IF WINDS BECOME
LIGHT ENOUGH LATE SUNDAY NIGHT, FROST COULD BE A POSSIBILITY.
THE BEGINNING OF THE WORKWEEK SHOULD BE FAIRLY QUIET WEATHER-WISE AS
AN UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL CONUS AND SURFACE HIGH
PRESSURE DOMINATES THE REGION. BY TUESDAY, ANOTHER UPPER LEVEL
TROUGH WILL BE MOVING ONSHORE OVER THE WEST COAST WITH INCREASING
SOUTHWESTERLY FLOW ALOFT OVER THE PLAINS AS THE AXIS OF THE UPPER
RIDGE MOVES EAST. AS A RESULT, LEE SIDE TROUGHING WILL DEVELOP OVER
EASTERN COLORADO WITH THE INCREASING SOUTHERLY FLOW PULLING LOW
LEVEL MOISTURE BACK NORTH FROM THE SOUTHERN PLAINS. THE GFS AND
ECMWF BOTH SHOW A SHORTWAVE TROUGH LIFTING OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL CONUS AROUND WEDNESDAY AND THURSDAY. THE
00Z RUN OF BOTH MODELS IS IN SOMEWHAT BETTER AGREEMENT THAN PREVIOUS
RUNS. WHILE THERE IS STILL SOME UNCERTAINTY AS WHERE LOW LEVEL
FEATURES WILL BE TO HELP FOCUS THUNDERSTORM DEVELOPMENT, THERE IS
SOME POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS SOUTH CENTRAL AND
PARTS OF SOUTHWEST KANSAS AROUND THURSDAY. CHANCES FOR THUNDERSTORMS
SHOULD CONTINUE OVER PARTS OF THE AREA INTO DAY SEVEN AS
SOUTHWESTERLY FLOW ALOFT CONTINUES OVER THE CENTRAL PLAINS WHILE LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH INTO KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1222 PM CDT SAT MAY 9 2015
MID TO LOW LEVEL CLOUDS WILL SLOWLY DISSIPATE BEHIND THE
THUNDERSTORMS THIS AFTERNOON LEADING TO VFR CONDITIONS. MORE
THUNDERSTORMS ARE EXPECTED THIS AFTERNOON BRINGING PERIODS OF MVFR
TO IFR CEILINGS AND VISIBILITIES. WINDS WILL GENERALLY BE FROM THE
SOUTHEAST AROUND 20 KNOTS GUSTING TO OVER 30 KNOTS AT TIMES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 49 67 40 / 80 70 10 10
GCK 70 44 63 37 / 80 70 10 10
EHA 72 44 63 37 / 70 20 10 10
LBL 72 46 66 40 / 70 40 10 10
HYS 66 53 66 40 / 70 80 10 10
P28 70 57 74 45 / 80 60 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 2 PM CDT THIS AFTERNOON FOR KSZ043>045-
063-064-076>080-087>090.
&&
$$
SYNOPSIS...HOVORKA_42
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1120 AM CDT SAT MAY 9 2015
...UPDATED SYNOPSIS SECTION...
.SYNOPSIS...
ISSUED AT 1120 AM CDT SAT MAY 9 2015
A STRONG UPPER LEVEL LOW CURRENTLY OVER THE FOUR CORNER`S REGION
WILL CONTINUE TO MOVE NORTHEAST INTO COLORADO THIS AFTERNOON INTO
THE EARLY EVENING HOURS. A 90+ KNOT 250 MB JET WILL EXTEND AROUND
THE PERIPHERY OF THIS LOW STRETCHING FROM SOUTHERN NEW MEXICO,
NORTHWARD THROUGH THE NM/TX BORDER AND ALONG THE KS/CO BORDER. LOW
TO MID LEVELS OF THE ATMOSPHERE ARE CURRENTLY SATURATED ALLOWING
MOSTLY CLOUDY SKIES TO BE OBSERVED ACROSS A MAJORITY OF THE CWA.
TOWARDS THE SURFACE, AN AREA OF LOW PRESSURE WILL BE LOCATED
ACROSS EASTERN COLORADO WITH AN ASSOCIATED WARM FRONT EXTENDING
EASTWARD THROUGH KANSAS. THIS WARM FRONT LOOKS TO SHIFT NORTHWARD
THIS AFTERNOON AND ALONG THE KS/NE BORDER BY THIS EVENING. A
DRYLINE WILL BE LOCATED ALONG THE KS/CO BORDER EARLY THIS
AFTERNOON SLIDING EASTWARD AS THE DAY PROGRESSES. MEANWHILE, MID
LEVELS OF THE ATMOSPHERE DRY OUT ACROSS FAR WESTERN KANSAS THIS
AFTERNOON LEADING TO BREAKS IN THE CLOUDS ALLOWING SUN TO
INFILTRATE TO THE SURFACE. WARMING TEMPERATURES ALONG WITH AMPLE
MOISTURE AND LIFT AT THE SURFACE WILL DESTABILIZE WESTERN KANSAS
WITH STRONG TO SEVERE THUNDERSTORMS EXPECTED LATE THIS AFTERNOON
INTO THE EVENING HOURS. PLEASE KEEP YOUR EYES ON THE WEATHER THIS
AFTERNOON INTO EVENING AND COME TO OUR WEBSITE, FACEBOOK, OR
TWITTER PAGE FOR THE MOST CURRENT SEVERE WEATHER INFORMATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM CDT SAT MAY 9 2015
...SIGNIFICANT SEVERE WEATHER EVENT LIKELY...
ALL THE FOCUS IN THE SHORT TERM IS HOW THE CONVECTIVE PICTURE
TODAY WILL EVOLVE AND WHAT WILL THE IMPACTS BE. IT SHOULD BE NOTED
THAT THERE IS STILL LARGE UNCERTAINTY IN HOW STORMS WILL EVOLVE,
SO KEEP UPDATED AS THE FORECAST IS ADJUSTED THROUGH THE DAY. THIS
UNCERTAINTY IS REFLECTED IN THE VARIOUS MESOSCALE MODELS THAT ARE
ALL OFFERING DIFFERENT SOLUTIONS. HAVE PUT THE THE HRRR ON THE
BACK BURNER BECAUSE THIS MODEL HAS BEEN DOING POORLY RECENTLY
(I.E. CONVECTION ACROSS OKLAHOMA/TEXAS LAST NIGHT). THE
OPERATIONAL NAM HAS BEEN DOING A LITTLE BETTER, SO INFLUENCE FROM
THIS MODEL WAS USED. PURELY SUBJECTIVELY, THE WRF-ARW HAS BEEN
DOING THE BEST AND POP AND MESOSCALE GUIDANCE WAS HEAVILY BIASED
TOWARDS THIS MESOSCALE MODEL.
THERE WILL BE TWO ROUNDS OF CONVECTION FOR TODAY. THE FIRST ROUND
WILL BE THIS MORNING AS CONVECTION MOVES FROM THE PANHANDLES
NORTHWARD TO SOUTHWEST KANSAS. THIS ACTIVITY IS ASSOCIATED WITH
WARM AIR ADVECTION AND A VORTMAX SWING THROUGH AHEAD OF THE MAIN
SYNOPTIC TROUGH. THUNDERSTORMS THIS MORNING WILL BE STRONG TO
PERHAPS MARGINALLY SEVERE. THE MAIN SHOW IS THIS AFTERNOON AND
EVENING AS THE SYNOPTIC LOW EJECTS AND THE NOSE OF A 80-90 KT
250-HPA JET MOVES CLOSER. INTENSE LEE CYCLOGENESIS IS EXPECTED
WITH A STRONG WIND FIELD AND RESULTANT SHEAR DEVELOPING ACROSS WESTERN
KANSAS THROUGH THE DAY. FROM THE WRF-ARW, THINK STORMS WILL REFIRE
ALONG THE DRYLINE DURING THE EARLY AFTERNOON ROUGHLY FROM COLBY
SOUTHEAST TO LIBERAL. THERE ARE A FEW QUESTIONS THOUGH ABOUT THIS
SECOND ROUND. 1) WILL CONVECTION THIS MORNING IMPEDE MOISTURE
RETURN BY THE AFTERNOON? 2) HOW MUCH RECOVERY WILL THERE BE IN THE
WAKE OF THE FIRST ROUND OF STORMS. MESOSCALE MODELS DO SUGGEST
SUFFICIENT INSTABILITY DEVELOPING BY THE AFTERNOON (2500 J/KG
SBCAPE). 3) SOMETHING THAT I NOTICED SEVERAL DAYS AGO, FORECAST
SKEW-T/LOG-P`S SHOW BACKING OF UPPER LEVEL WINDS. THIS COULD
ENCOURAGE HP SUPERCELL (MESSY) STORM TYPE. THERE IS ENOUGH
ORTHOGONALITY THOUGH BETWEEN THE DRYLINE AND 850-300 HPA FLOW THAT
I EXPECT AT LEAST DISCRETE HP SUPERCELLS. 4) WILL THE WRF-ARW
VERIFY OR WILL IT BE WRONG LIKE THE HRRR WAS LAST NIGHT. SO,
SEVERAL QUESTIONS THAT WILL NEED TO BE ANSWERED. THE MODERATE RISK
FROM SPC ALSO HIGHLIGHTS THE UNCERTAINTY THAT I HAVE. ANYWAY, THE
ENVIRONMENT IS PRIMED FOR SIGNIFICANT SEVERE WEATHER. LARGE HAIL
(2-3") LOOKS LIKELY FROM THE LARGE HAIL PARAMETER. FOR TORNADOES,
SIGNIFICANT TORNADO PARAMETER OF 5-10, 250-300 M2S2 SFC-3 KM SRH,
20-30 KT OF 0-1 BULK SHEAR, AND A LOOPING HODOGRAPHS CLEARLY GIVEN
CREDENCE FOR STRONG TORNADOES (PERHAPS A VIOLENT TORNADO SHOULD
MESOSCALE STORM DETAILS PLAY OUT CORRECTLY/OFB LAID OUT). THE
WRF-ARW ALSO IS FORECASTING UPDRAFT HELICITY, SO CLEARLY THE MODEL
IS TRYING TO DEPICT ROTATING STORMS (SUPERCELLS). WITH A
COMBINATION OF CAPE AND LOW LEVEL SHEAR, THINK THE BEST AREA FROM
TORNADOES IS PROBABLY IN THE GARDEN CITY, MEADE, DODGE CITY, SCOTT
CITY AREA THIS AFTERNOON. AGAIN, YOU CAN HAVE ALL THE PERFECT
PARAMETERS, BUT IF INSTABILITY IS LACKING DUE TO LINGERING CLOUD
COVER FROM AM STORMS... THEN NONE OF THIS WILL MATTER AND THE
SEVERE THREAT WILL BE MORE SUBDUED. WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT. LASTLY, SEE THE YOUTUBE VIDEO THAT WAS PUT UP THIS
MORNING FOR A GRAPHIC REPRESENTATION OF ALL THIS TECHNICAL TALK
ABOVE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 257 AM CDT SAT MAY 9 2015
BY SUNDAY MORNING, THE UPPER LOW WILL BE OVER THE NORTHEAST CORNER
OF COLORADO AND WILL BE LIFTING INTO THE EASTERN DAKOTAS BY SUNDAY
EVENING. THE ATTENDANT SURFACE LOW WILL ALSO LIFT NORTHEAST OUT OF
THE REGION. EARLY ON, SOME WRAPAROUND SHOWERS WILL BE POSSIBLE OVER
WEST CENTRAL KANSAS BUT THESE SHOULD BE ENDING FAIRLY QUICKLY AS THE
UPPER LOW MOVES OUT. THROUGH THE REMAINDER OF THE DAY, WESTERN
KANSAS WILL BE UNDER CYCLONIC MID LEVEL FLOW IN THE WAKE OF THE
UPPER LOW. COOLER, DRIER AIR WILL BE SPREADING INTO THE AREA BUT WE
SHOULD SEE PERIODS OF CLOUDS ALONG WITH BREEZY CONDITIONS ESPECIALLY
WITH MAX HEATING DURING THE DAY. LOW LEVEL COLD ADVECTION CONTINUES
INTO SUNDAY NIGHT WHICH SHOULD KEEP WINDS UP SOMEWHAT ACROSS THE
AREA. TEMPERATURES SHOULD FALL INTO THE MID 30S OVER WESTERN
SECTIONS OF THE AREA...ALONG THE COLORADO BORDER. IF WINDS BECOME
LIGHT ENOUGH LATE SUNDAY NIGHT, FROST COULD BE A POSSIBILITY.
THE BEGINNING OF THE WORKWEEK SHOULD BE FAIRLY QUIET WEATHER-WISE AS
AN UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL CONUS AND SURFACE HIGH
PRESSURE DOMINATES THE REGION. BY TUESDAY, ANOTHER UPPER LEVEL
TROUGH WILL BE MOVING ONSHORE OVER THE WEST COAST WITH INCREASING
SOUTHWESTERLY FLOW ALOFT OVER THE PLAINS AS THE AXIS OF THE UPPER
RIDGE MOVES EAST. AS A RESULT, LEE SIDE TROUGHING WILL DEVELOP OVER
EASTERN COLORADO WITH THE INCREASING SOUTHERLY FLOW PULLING LOW
LEVEL MOISTURE BACK NORTH FROM THE SOUTHERN PLAINS. THE GFS AND
ECMWF BOTH SHOW A SHORTWAVE TROUGH LIFTING OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL CONUS AROUND WEDNESDAY AND THURSDAY. THE
00Z RUN OF BOTH MODELS IS IN SOMEWHAT BETTER AGREEMENT THAN PREVIOUS
RUNS. WHILE THERE IS STILL SOME UNCERTAINTY AS WHERE LOW LEVEL
FEATURES WILL BE TO HELP FOCUS THUNDERSTORM DEVELOPMENT, THERE IS
SOME POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS SOUTH CENTRAL AND
PARTS OF SOUTHWEST KANSAS AROUND THURSDAY. CHANCES FOR THUNDERSTORMS
SHOULD CONTINUE OVER PARTS OF THE AREA INTO DAY SEVEN AS
SOUTHWESTERLY FLOW ALOFT CONTINUES OVER THE CENTRAL PLAINS WHILE LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH INTO KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 658 AM CDT SAT MAY 9 2015
IFR TO LIFR CONDITIONS IN LOW STRATUS ALONG WITH DRIZZLE AND MIST
WILL PREVAIL AT THE TERMINALS THROUGH THE EARLY PART OF THIS
PERIOD. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH
THE MID TO LATE MORNING HOURS AND AGAIN LATER THIS AFTERNOON AND
EVENING. THE AFTERNOON AND EVENING STORMS COULD BE ACCOMPANIED
WITH LARGE HAIL AND 40-50 KNOT WIND GUSTS. VFR CONDITIONS SHOULD
SPREAD NORTHEAST ACROSS WESTERN AND CENTRAL KANSAS LATE IN THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 49 67 40 / 80 80 10 10
GCK 70 45 63 37 / 80 80 10 10
EHA 72 43 63 37 / 70 20 10 10
LBL 72 46 66 40 / 70 50 10 10
HYS 66 53 66 40 / 60 80 10 10
P28 70 56 74 45 / 80 70 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HOVORKA_42
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
700 AM CDT SAT MAY 9 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM CDT SAT MAY 9 2015
...SIGNIFICANT SEVERE WEATHER EVENT LIKELY...
ALL THE FOCUS IN THE SHORT TERM IS HOW THE CONVECTIVE PICTURE
TODAY WILL EVOLVE AND WHAT WILL THE IMPACTS BE. IT SHOULD BE NOTED
THAT THERE IS STILL LARGE UNCERTAINTY IN HOW STORMS WILL EVOLVE,
SO KEEP UPDATED AS THE FORECAST IS ADJUSTED THROUGH THE DAY. THIS
UNCERTAINTY IS REFLECTED IN THE VARIOUS MESOSCALE MODELS THAT ARE
ALL OFFERING DIFFERENT SOLUTIONS. HAVE PUT THE THE HRRR ON THE
BACK BURNER BECAUSE THIS MODEL HAS BEEN DOING POORLY RECENTLY
(I.E. CONVECTION ACROSS OKLAHOMA/TEXAS LAST NIGHT). THE
OPERATIONAL NAM HAS BEEN DOING A LITTLE BETTER, SO INFLUENCE FROM
THIS MODEL WAS USED. PURELY SUBJECTIVELY, THE WRF-ARW HAS BEEN
DOING THE BEST AND POP AND MESOSCALE GUIDANCE WAS HEAVILY BIASED
TOWARDS THIS MESOSCALE MODEL.
THERE WILL BE TWO ROUNDS OF CONVECTION FOR TODAY. THE FIRST ROUND
WILL BE THIS MORNING AS CONVECTION MOVES FROM THE PANHANDLES
NORTHWARD TO SOUTHWEST KANSAS. THIS ACTIVITY IS ASSOCIATED WITH
WARM AIR ADVECTION AND A VORTMAX SWING THROUGH AHEAD OF THE MAIN
SYNOPTIC TROUGH. THUNDERSTORMS THIS MORNING WILL BE STRONG TO
PERHAPS MARGINALLY SEVERE. THE MAIN SHOW IS THIS AFTERNOON AND
EVENING AS THE SYNOPTIC LOW EJECTS AND THE NOSE OF A 80-90 KT
250-HPA JET MOVES CLOSER. INTENSE LEE CYCLOGENESIS IS EXPECTED
WITH A STRONG WIND FIELD AND RESULTANT SHEAR DEVELOPING ACROSS WESTERN
KANSAS THROUGH THE DAY. FROM THE WRF-ARW, THINK STORMS WILL REFIRE
ALONG THE DRYLINE DURING THE EARLY AFTERNOON ROUGHLY FROM COLBY
SOUTHEAST TO LIBERAL. THERE ARE A FEW QUESTIONS THOUGH ABOUT THIS
SECOND ROUND. 1) WILL CONVECTION THIS MORNING IMPEDE MOISTURE
RETURN BY THE AFTERNOON? 2) HOW MUCH RECOVERY WILL THERE BE IN THE
WAKE OF THE FIRST ROUND OF STORMS. MESOSCALE MODELS DO SUGGEST
SUFFICIENT INSTABILITY DEVELOPING BY THE AFTERNOON (2500 J/KG
SBCAPE). 3) SOMETHING THAT I NOTICED SEVERAL DAYS AGO, FORECAST
SKEW-T/LOG-P`S SHOW BACKING OF UPPER LEVEL WINDS. THIS COULD
ENCOURAGE HP SUPERCELL (MESSY) STORM TYPE. THERE IS ENOUGH
ORTHOGONALITY THOUGH BETWEEN THE DRYLINE AND 850-300 HPA FLOW THAT
I EXPECT AT LEAST DISCRETE HP SUPERCELLS. 4) WILL THE WRF-ARW
VERIFY OR WILL IT BE WRONG LIKE THE HRRR WAS LAST NIGHT. SO,
SEVERAL QUESTIONS THAT WILL NEED TO BE ANSWERED. THE MODERATE RISK
FROM SPC ALSO HIGHLIGHTS THE UNCERTAINTY THAT I HAVE. ANYWAY, THE
ENVIRONMENT IS PRIMED FOR SIGNIFICANT SEVERE WEATHER. LARGE HAIL
(2-3") LOOKS LIKELY FROM THE LARGE HAIL PARAMETER. FOR TORNADOES,
SIGNIFICANT TORNADO PARAMETER OF 5-10, 250-300 M2S2 SFC-3 KM SRH,
20-30 KT OF 0-1 BULK SHEAR, AND A LOOPING HODOGRAPHS CLEARLY GIVEN
CREDENCE FOR STRONG TORNADOES (PERHAPS A VIOLENT TORNADO SHOULD
MESOSCALE STORM DETAILS PLAY OUT CORRECTLY/OFB LAID OUT). THE
WRF-ARW ALSO IS FORECASTING UPDRAFT HELICITY, SO CLEARLY THE MODEL
IS TRYING TO DEPICT ROTATING STORMS (SUPERCELLS). WITH A
COMBINATION OF CAPE AND LOW LEVEL SHEAR, THINK THE BEST AREA FROM
TORNADOES IS PROBABLY IN THE GARDEN CITY, MEADE, DODGE CITY, SCOTT
CITY AREA THIS AFTERNOON. AGAIN, YOU CAN HAVE ALL THE PERFECT
PARAMETERS, BUT IF INSTABILITY IS LACKING DUE TO LINGERING CLOUD
COVER FROM AM STORMS... THEN NONE OF THIS WILL MATTER AND THE
SEVERE THREAT WILL BE MORE SUBDUED. WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT. LASTLY, SEE THE YOUTUBE VIDEO THAT WAS PUT UP THIS
MORNING FOR A GRAPHIC REPRESENTATION OF ALL THIS TECHNICAL TALK
ABOVE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 257 AM CDT SAT MAY 9 2015
BY SUNDAY MORNING, THE UPPER LOW WILL BE OVER THE NORTHEAST CORNER
OF COLORADO AND WILL BE LIFTING INTO THE EASTERN DAKOTAS BY SUNDAY
EVENING. THE ATTENDANT SURFACE LOW WILL ALSO LIFT NORTHEAST OUT OF
THE REGION. EARLY ON, SOME WRAPAROUND SHOWERS WILL BE POSSIBLE OVER
WEST CENTRAL KANSAS BUT THESE SHOULD BE ENDING FAIRLY QUICKLY AS THE
UPPER LOW MOVES OUT. THROUGH THE REMAINDER OF THE DAY, WESTERN
KANSAS WILL BE UNDER CYCLONIC MID LEVEL FLOW IN THE WAKE OF THE
UPPER LOW. COOLER, DRIER AIR WILL BE SPREADING INTO THE AREA BUT WE
SHOULD SEE PERIODS OF CLOUDS ALONG WITH BREEZY CONDITIONS ESPECIALLY
WITH MAX HEATING DURING THE DAY. LOW LEVEL COLD ADVECTION CONTINUES
INTO SUNDAY NIGHT WHICH SHOULD KEEP WINDS UP SOMEWHAT ACROSS THE
AREA. TEMPERATURES SHOULD FALL INTO THE MID 30S OVER WESTERN
SECTIONS OF THE AREA...ALONG THE COLORADO BORDER. IF WINDS BECOME
LIGHT ENOUGH LATE SUNDAY NIGHT, FROST COULD BE A POSSIBILITY.
THE BEGINNING OF THE WORKWEEK SHOULD BE FAIRLY QUIET WEATHER-WISE AS
AN UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL CONUS AND SURFACE HIGH
PRESSURE DOMINATES THE REGION. BY TUESDAY, ANOTHER UPPER LEVEL
TROUGH WILL BE MOVING ONSHORE OVER THE WEST COAST WITH INCREASING
SOUTHWESTERLY FLOW ALOFT OVER THE PLAINS AS THE AXIS OF THE UPPER
RIDGE MOVES EAST. AS A RESULT, LEE SIDE TROUGHING WILL DEVELOP OVER
EASTERN COLORADO WITH THE INCREASING SOUTHERLY FLOW PULLING LOW
LEVEL MOISTURE BACK NORTH FROM THE SOUTHERN PLAINS. THE GFS AND
ECMWF BOTH SHOW A SHORTWAVE TROUGH LIFTING OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL CONUS AROUND WEDNESDAY AND THURSDAY. THE
00Z RUN OF BOTH MODELS IS IN SOMEWHAT BETTER AGREEMENT THAN PREVIOUS
RUNS. WHILE THERE IS STILL SOME UNCERTAINTY AS WHERE LOW LEVEL
FEATURES WILL BE TO HELP FOCUS THUNDERSTORM DEVELOPMENT, THERE IS
SOME POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS SOUTH CENTRAL AND
PARTS OF SOUTHWEST KANSAS AROUND THURSDAY. CHANCES FOR THUNDERSTORMS
SHOULD CONTINUE OVER PARTS OF THE AREA INTO DAY SEVEN AS
SOUTHWESTERLY FLOW ALOFT CONTINUES OVER THE CENTRAL PLAINS WHILE LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH INTO KANSAS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 658 AM CDT SAT MAY 9 2015
IFR TO LIFR CONDITIONS IN LOW STRATUS ALONG WITH DRIZZLE AND MIST
WILL PREVAIL AT THE TERMINALS THROUGH THE EARLY PART OF THIS
PERIOD. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH
THE MID TO LATE MORNING HOURS AND AGAIN LATER THIS AFTERNOON AND
EVENING. THE AFTERNOON AND EVENING STORMS COULD BE ACCOMPANIED
WITH LARGE HAIL AND 40-50 KNOT WIND GUSTS. VFR CONDITIONS SHOULD
SPREAD NORTHEAST ACROSS WESTERN AND CENTRAL KANSAS LATE IN THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 73 49 67 40 / 70 80 10 10
GCK 72 45 63 37 / 80 30 10 10
EHA 74 43 63 37 / 50 10 10 10
LBL 76 46 66 40 / 50 20 10 10
HYS 71 53 66 40 / 70 90 10 10
P28 75 56 74 45 / 30 30 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
444 AM CDT SAT MAY 9 2015
...UPDATED SHORT TERM...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM CDT SAT MAY 9 2015
...SIGNIFICANT SEVERE WEATHER EVENT LIKELY...
ALL THE FOCUS IN THE SHORT TERM IS HOW THE CONVECTIVE PICTURE
TODAY WILL EVOLVE AND WHAT WILL THE IMPACTS BE. IT SHOULD BE NOTED
THAT THERE IS STILL LARGE UNCERTAINTY IN HOW STORMS WILL EVOLVE,
SO KEEP UPDATED AS THE FORECAST IS ADJUSTED THROUGH THE DAY. THIS
UNCERTAINTY IS REFLECTED IN THE VARIOUS MESOSCALE MODELS THAT ARE
ALL OFFERING DIFFERENT SOLUTIONS. HAVE PUT THE THE HRRR ON THE
BACK BURNER BECAUSE THIS MODEL HAS BEEN DOING POORLY RECENTLY
(I.E. CONVECTION ACROSS OKLAHOMA/TEXAS LAST NIGHT). THE
OPERATIONAL NAM HAS BEEN DOING A LITTLE BETTER, SO INFLUENCE FROM
THIS MODEL WAS USED. PURELY SUBJECTIVELY, THE WRF-ARW HAS BEEN
DOING THE BEST AND POP AND MESOSCALE GUIDANCE WAS HEAVILY BIASED
TOWARDS THIS MESOSCALE MODEL.
THERE WILL BE TWO ROUNDS OF CONVECTION FOR TODAY. THE FIRST ROUND
WILL BE THIS MORNING AS CONVECTION MOVES FROM THE PANHANDLES
NORTHWARD TO SOUTHWEST KANSAS. THIS ACTIVITY IS ASSOCIATED WITH
WARM AIR ADVECTION AND A VORTMAX SWING THROUGH AHEAD OF THE MAIN
SYNOPTIC TROUGH. THUNDERSTORMS THIS MORNING WILL BE STRONG TO
PERHAPS MARGINALLY SEVERE. THE MAIN SHOW IS THIS AFTERNOON AND
EVENING AS THE SYNOPTIC LOW EJECTS AND THE NOSE OF A 80-90 KT
250-HPA JET MOVES CLOSER. INTENSE LEE CYCLOGENESIS IS EXPECTED
WITH A STRONG WIND FIELD AND RESULTANT SHEAR DEVELOPING ACROSS WESTERN
KANSAS THROUGH THE DAY. FROM THE WRF-ARW, THINK STORMS WILL REFIRE
ALONG THE DRYLINE DURING THE EARLY AFTERNOON ROUGHLY FROM COLBY
SOUTHEAST TO LIBERAL. THERE ARE A FEW QUESTIONS THOUGH ABOUT THIS
SECOND ROUND. 1) WILL CONVECTION THIS MORNING IMPEDE MOISTURE
RETURN BY THE AFTERNOON? 2) HOW MUCH RECOVERY WILL THERE BE IN THE
WAKE OF THE FIRST ROUND OF STORMS. MESOSCALE MODELS DO SUGGEST
SUFFICIENT INSTABILITY DEVELOPING BY THE AFTERNOON (2500 J/KG
SBCAPE). 3) SOMETHING THAT I NOTICED SEVERAL DAYS AGO, FORECAST
SKEW-T/LOG-P`S SHOW BACKING OF UPPER LEVEL WINDS. THIS COULD
ENCOURAGE HP SUPERCELL (MESSY) STORM TYPE. THERE IS ENOUGH
ORTHOGONALITY THOUGH BETWEEN THE DRYLINE AND 850-300 HPA FLOW THAT
I EXPECT AT LEAST DISCRETE HP SUPERCELLS. 4) WILL THE WRF-ARW
VERIFY OR WILL IT BE WRONG LIKE THE HRRR WAS LAST NIGHT. SO,
SEVERAL QUESTIONS THAT WILL NEED TO BE ANSWERED. THE MODERATE RISK
FROM SPC ALSO HIGHLIGHTS THE UNCERTAINTY THAT I HAVE. ANYWAY, THE
ENVIRONMENT IS PRIMED FOR SIGNIFICANT SEVERE WEATHER. LARGE HAIL
(2-3") LOOKS LIKELY FROM THE LARGE HAIL PARAMETER. FOR TORNADOES,
SIGNIFICANT TORNADO PARAMETER OF 5-10, 250-300 M2S2 SFC-3 KM SRH,
20-30 KT OF 0-1 BULK SHEAR, AND A LOOPING HODOGRAPHS CLEARLY GIVEN
CREDENCE FOR STRONG TORNADOES (PERHAPS A VIOLENT TORNADO SHOULD
MESOSCALE STORM DETAILS PLAY OUT CORRECTLY/OFB LAID OUT). THE
WRF-ARW ALSO IS FORECASTING UPDRAFT HELICITY, SO CLEARLY THE MODEL
IS TRYING TO DEPICT ROTATING STORMS (SUPERCELLS). WITH A
COMBINATION OF CAPE AND LOW LEVEL SHEAR, THINK THE BEST AREA FROM
TORNADOES IS PROBABLY IN THE GARDEN CITY, MEADE, DODGE CITY, SCOTT
CITY AREA THIS AFTERNOON. AGAIN, YOU CAN HAVE ALL THE PERFECT
PARAMETERS, BUT IF INSTABILITY IS LACKING DUE TO LINGERING CLOUD
COVER FROM AM STORMS... THEN NONE OF THIS WILL MATTER AND THE
SEVERE THREAT WILL BE MORE SUBDUED. WILL BE INTERESTING TO SEE HOW
THIS PLAYS OUT. LASTLY, SEE THE YOUTUBE VIDEO THAT WAS PUT UP THIS
MORNING FOR A GRAPHIC REPRESENTATION OF ALL THIS TECHNICAL TALK
ABOVE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 257 AM CDT SAT MAY 9 2015
BY SUNDAY MORNING, THE UPPER LOW WILL BE OVER THE NORTHEAST CORNER
OF COLORADO AND WILL BE LIFTING INTO THE EASTERN DAKOTAS BY SUNDAY
EVENING. THE ATTENDANT SURFACE LOW WILL ALSO LIFT NORTHEAST OUT OF
THE REGION. EARLY ON, SOME WRAPAROUND SHOWERS WILL BE POSSIBLE OVER
WEST CENTRAL KANSAS BUT THESE SHOULD BE ENDING FAIRLY QUICKLY AS THE
UPPER LOW MOVES OUT. THROUGH THE REMAINDER OF THE DAY, WESTERN
KANSAS WILL BE UNDER CYCLONIC MID LEVEL FLOW IN THE WAKE OF THE
UPPER LOW. COOLER, DRIER AIR WILL BE SPREADING INTO THE AREA BUT WE
SHOULD SEE PERIODS OF CLOUDS ALONG WITH BREEZY CONDITIONS ESPECIALLY
WITH MAX HEATING DURING THE DAY. LOW LEVEL COLD ADVECTION CONTINUES
INTO SUNDAY NIGHT WHICH SHOULD KEEP WINDS UP SOMEWHAT ACROSS THE
AREA. TEMPERATURES SHOULD FALL INTO THE MID 30S OVER WESTERN
SECTIONS OF THE AREA...ALONG THE COLORADO BORDER. IF WINDS BECOME
LIGHT ENOUGH LATE SUNDAY NIGHT, FROST COULD BE A POSSIBILITY.
THE BEGINNING OF THE WORKWEEK SHOULD BE FAIRLY QUIET WEATHER-WISE AS
AN UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL CONUS AND SURFACE HIGH
PRESSURE DOMINATES THE REGION. BY TUESDAY, ANOTHER UPPER LEVEL
TROUGH WILL BE MOVING ONSHORE OVER THE WEST COAST WITH INCREASING
SOUTHWESTERLY FLOW ALOFT OVER THE PLAINS AS THE AXIS OF THE UPPER
RIDGE MOVES EAST. AS A RESULT, LEE SIDE TROUGHING WILL DEVELOP OVER
EASTERN COLORADO WITH THE INCREASING SOUTHERLY FLOW PULLING LOW
LEVEL MOISTURE BACK NORTH FROM THE SOUTHERN PLAINS. THE GFS AND
ECMWF BOTH SHOW A SHORTWAVE TROUGH LIFTING OUT OF THE DESERT
SOUTHWEST INTO THE CENTRAL CONUS AROUND WEDNESDAY AND THURSDAY. THE
00Z RUN OF BOTH MODELS IS IN SOMEWHAT BETTER AGREEMENT THAN PREVIOUS
RUNS. WHILE THERE IS STILL SOME UNCERTAINTY AS WHERE LOW LEVEL
FEATURES WILL BE TO HELP FOCUS THUNDERSTORM DEVELOPMENT, THERE IS
SOME POTENTIAL FOR SIGNIFICANT RAINFALL ACROSS SOUTH CENTRAL AND
PARTS OF SOUTHWEST KANSAS AROUND THURSDAY. CHANCES FOR THUNDERSTORMS
SHOULD CONTINUE OVER PARTS OF THE AREA INTO DAY SEVEN AS
SOUTHWESTERLY FLOW ALOFT CONTINUES OVER THE CENTRAL PLAINS WHILE LOW
LEVEL MOISTURE CONTINUES TO STREAM NORTH INTO KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAY 9 2015
GENERALLY POOR FLIGHT CONDITIONS THROUGH THE 09.06Z TO 10.06Z TAF PERIOD.
CIGS WILL START AT IFR FOR KGCK/KDDC THROUGH THE OVERNIGHT IN ASSOCIATION
WITH LOW STRATUS. MVFR CIGS EXPECTED FOR KHYS. THERE STILL IS UNCERTAINTY
IN CONVECTIVE EVOLUTION FOR TOMORROW BUT HAVE TWO TEMPO CB/TSRA PERIODS
IN THE TAFS. ONE FOR THE MORNING BETWEEN 12Z AND 16Z AND THE OTHER FOR
21Z TO 00Z. THIS MAY NEED TO BE ADJUSTED AS CONVECTIVE/RADAR TRENDS
BECOME CLEAR IN FUTURE TAF FORECASTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 73 49 67 40 / 70 80 10 10
GCK 72 45 63 37 / 80 30 10 10
EHA 74 43 63 37 / 50 10 10 10
LBL 76 46 66 40 / 50 20 10 10
HYS 71 53 66 40 / 70 90 10 10
P28 75 56 74 45 / 30 30 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...GERARD
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1241 AM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 1242 AM CDT SAT MAY 9 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 06Z TAF ISSUANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 158 PM CDT FRI MAY 8 2015
SHOWERS AND THUNDERSTORMS...MANY ASSOCIATED WITH AN MCV IN
SOUTHEAST MISSOURI...WILL CONTINUE TO PUSH ACROSS THE AREA THIS
AFTERNOON. HRRR MODEL HANDLED THIS SITUATION VERY WELL AND WILL BE
FOLLOWED INTO THE NIGHTTIME HOURS. THE MCV MAY ASSIST IN AIDING
STORMS TO PRODUCE ISOLATED SEVERE WIND GUSTS THIS AFTERNOON.
GFS SEEMS TO HAVE A DECENT AND CONSISTENT HANDLE ON THINGS OVER
THE NEXT COUPLE OF DAYS. ECMWF IS SIMILAR IN CHARACTER. AFTER THE
MAIN ROUND THIS AFTERNOON...ONLY SCATTERED CONVECTION EXPECTED
UNTIL LATER SATURDAY MORNING WHEN THE NEXT PIECE OF ENERGY MOVES
INTO SEMO. HOWEVER...LOOKS LIKE MOST OF THAT WILL MOVE MORE INTO
ILLINOIS AND POSSIBLY SOUTHWEST INDIANA.
A LULL THEN SETS IN FOR SATURDAY NIGHT INTO SUNDAY WITH SOME
SCATTERED STORMS POSSIBLE. CAP IS NEVER TOO STRONG DURING THIS
PERIOD. LATE SUNDAY NIGHT THE MAIN TROUGH BEGINS TO LIFT OUT AND
WILL BRING A BETTER STORM COVERAGE INTO SOUTHEAST MISSOURI.
SEVERE CHANCES ARE SOMEWHAT LIMITED THROUGH THIS PERIOD. ISOLATED
SEVERE IS POSSIBLE DURING THE AFTERNOON AND EVENINGS BUT ORGANIZED
SEVERE WEATHER IS NOT EXPECTED.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 158 PM CDT MAY 8 2015
THE BEGINNING OF THE EXTENDED PERIOD WILL START WITH THE PASSAGE OF
A COLD FRONT THROUGH THE PAH FORECAST AREA...TRAILING FROM A CYCLONE
MOVING INTO THE GREAT LAKES REGION. THIS SHOULD RESULT IN RAPID
CESSATION OF PCPN (SHOWERS/TSTMS) BY EVENING WEST TO EAST ACROSS OUR
REGION...AND A TURN OF THE LOW LEVEL WINDS TO THE WEST.
UNDER QUASI-ZONAL FLOW ALOFT...AND A RIDGE OF HIGH SFC PRESSURE...
MOST OF THE PAH FORECAST AREA SHOULD BE RAIN-FREE THROUGH WED...
EXCEPT PERHAPS THE FAR WEST. FROM MID WEEK ON...THE 00Z ECMWF SEEMED
TO BE THE ODD MODEL OUT...IN DISAGREEMENT WITH ITS ENSEMBLE MEAN
(AND THE GEFS/NAEFS). IT SHOWED A TENDENCY TOWARD A QUICKER RETURN
FLOW DUE TO EXTRA MID LEVEL SHRTWV ENERGY TO THE SE OF A WRN CONUS
TROF. THE 12Z RUN CAME IN LOOKING QUITE SIMILAR TO THE MORE
CONSISTENT GFS...WHICH SHOWED MORE OF AN ERLY LOW LEVEL FLOW AND
DRIER CONDITIONS INTO PART OF THU. THUS...A SLOW RAMPING UP OF
(LIMITED) POPS FROM WEST TO EAST WAS LEFT IN THE FORECAST WED
NIGHT/THU/THU NIGHT. BY FRI...PCPN SEEMS A BIT MORE PROBABLE WITH A
SFC WARM FRONT SOMEWHERE IN THE VICINITY. OVERALL...CONFIDENCE IN
WHERE AND WHEN IT WILL BE RAINING FROM MID WEEK ON IS IFFY.
TEMPS DURING THE EXTENDED PERIOD CAN BE EXPECTED TO BE NEAR
SEASONABLE LEVELS.
&&
.AVIATION...
ISSUED AT 1242 AM CDT SAT MAY 9 2015
THE TAFS ARE VFR OUTSIDE OF CONVECTION.
SCATTERED SHOWERS HAVE DEVELOPED NEAR THE MS RIVER JUST
WEST/SOUTHWEST OF KPAH IN THE LAST HOUR. THIS ACTIVITY SHOULD MOVE
NORTHEAST THROUGH THE KPAH AREA IN THE FIRST FEW HOURS OF THE
PERIOD. WILL MONITOR ITS MOVEMENT AND MAY NEED TO INSERT A MENTION
OF SHOWERS OR EVEN TS AT KEVV AND KOWB LATER THIS MORNING.
OTHERWISE...A LARGE MASS OF CONVECTION OVER SOUTHWEST/WEST
ARKANSAS WILL MOVE/DEVELOP NORTHEAST INTO OUR REGION LATER
SATURDAY. BEST GUESS FOR TS IS MIDDAY/EARLY AFTERNOON AT KCGI AND
KPAH...AND LATE AFTERNOON/EARLY EVENING AT KEVV AND KOWB.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...PS
LONG TERM...DB
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
124 AM EDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 124 AM EDT SAT MAY 9 2015
UPDATED FOG THREAT TO INCLUDE MORE AREAS TO WIDESPREAD FOR AREAS
WHICH SAW A FEW SHOWERS EARLIER LAST EVENING. ALSO UPDATED
TEMPERATURES AND DEWPOINTS TO REFLECT CURRENT TRENDS. DRY WEATHER
SHOULD CONTINUE THROUGH DAWN.
UPDATE ISSUED AT 940 PM EDT FRI MAY 8 2015
HAVE REMOVED MENTION OF SHOWERS FROM THE GRIDS WITH THE EXCEPTION
OF FAR EASTERN PIKE/LETCHER COUNTIES FOR THE NEXT HOUR. ALSO
DECREASED SKY COVER DUE TO THE AFTERNOON CU DISSIPATING.
OTHERWISE...FORECAST REMAINS ON TRACK. UPDATED T AND TD GRIDS TO
ALIGN THEM WITH RECENT OBSERVATIONS. SENT UPDATED GRIDS TO NDFD
AND WEB SERVERS.
UPDATE ISSUED AT 630 PM EDT FRI MAY 8 2015
ISOLATED SHOWERS AND STORMS ARE STILL POPPING UP ACROSS THE
SOUTHERN HALF OF OUR FORECAST AREA SO HAVE KEPT SLIGHT CHANCE POPS
IN THE GRIDS FOR THE NEXT FEW HOURS. OTHERWISE...FORECAST APPEARS
TO BE ON TRACK SO MADE MINOR ADJUSTMENTS TO T AND TD GIRDS TO
ALIGN THEM WITH MOST RECENT OBS. SENT UPDATED GRIDS TO NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 350 PM EDT FRI MAY 8 2015
18Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE HOLDING ON OVER EASTERN
KENTUCKY AND TENNESSEE WHILE LOWER PRESSURE SETTLES DEEPER INTO
THE PLAINS AND MID MISSISSIPPI VALLEY. IN ADDITION...SUB TROPICAL
STORM ANA IS SEEN OFF THE COAST OF SOUTH CAROLINA. WITH LESS
IN THE WAY OF MORNING CLOUD COVER TODAY THE INITIAL STORMS
STARTED EARLIER THAN YESTERDAY...THOUGH SO FAR COVERAGE HAS BEEN
MORE ISOLATED. THEIR SLOW MOVEMENT WILL LEAD TO CONCERNS FOR
HEAVY RAINS AND A POTENTIAL FOR HIGHLY LOCALIZED FLOODING THROUGH
THE FIRST PART OF THE EVENING. OTHERWISE...TEMPERATURES ARE
PEAKING IN THE MID AND UPPER 80S WHILE DEWPOINTS RANGE FROM THE
MID 50S TO LOW 60S ACROSS THE AREA...AMID LIGHT AND VARIABLE
WINDS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE FAIRLY STEADY
STATE PATTERN OVER THE REGION INTO SUNDAY MORNING. THEY ALL
DEPICT A LARGE RIDGE OF MODERATE STRENGTH OVER THE SOUTHEAST THIRD
OF THE NATION. IN THE MIDDLE OF THIS RIDGE IS A COMPACT UPPER LOW
ASSOCIATED WITH ANA...WHILE TO THE WEST A HEALTHY CLOSED LOW
TROUGH IS PROGGED TO ROLL EAST THEN NORTHEAST FROM THE FOUR
CORNERS REGION AND INTO THE HIGH PLAINS. THIS WESTERN TROUGH WILL
OPEN UP A BIT DURING THIS PROCESS ALLOWING WAVES OF ENERGY TO
ESCAPE AND DRIFT INTO THE OHIO VALLEY IN THE BROAD SOUTHWEST
FLOW. THESE BITS MAY SCRAPE CLOSE ENOUGH TO EAST KENTUCKY TO ADD
TO A POTENTIAL FOR CONVECTION...AT TIMES...THROUGH THE SHORT
TERM THOUGH THE DIURNAL CYCLE WILL BE DOMINANT. GIVEN THE MODEL
AGREEMENT FOR OUR AREA HAVE FOLLOWED A GENERAL BLEND WITH
EMPHASIS ON THE HRRR AND NAM12 FOR DETAILS.
SENSIBLE WEATHER WILL CONTINUE THIS PERSISTENT PATTERN WITH THE
ADDITION OF A BETTER POTENTIAL FOR EXCESSIVE RAINS FROM ANY
SCATTERED TO ISOLATED STORMS DUE TO INCREASING PW AND SLOW STORM
MOTION. TEMPERATURES WILL BE FAIRLY UNIFORM...TOO...REACHING THE
MID AND UPPER 80S AGAIN SATURDAY AND IN THE MID 50S TO MID 60S
EACH NIGHT VARYING FROM THE COOLER NORTHEAST VALLEYS TO THE
MILD SOUTHWEST RIDGES. WILL CONTINUE INCLUSION OF PATCHY FOG IN
THE VALLEYS EACH NIGHT TOWARDS DAWN.
AGAIN USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD AND
WIND GRIDS INITIALLY...FOLLOWED BY THE SUPERBLEND. DID ENHANCE
THE MIN TEMPS FOR RIDGE AND VALLEY DIFFERENCES TONIGHT AND
SATURDAY NIGHT. AS FOR POPS...ENDED UP MOST SIMILAR TO THE MET
NUMBERS...THOUGH WITH AN EXAGGERATED DIURNAL CURVE THAT KEEPS THE
POPS LOWER DURING THE HEART OF THE NIGHT AND THROUGH THE LATE
MORNING HOURS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 353 PM EDT FRI MAY 8 2015
UPPER LEVEL RIDGING WILL CONTINUE TO DOMINATE THE FIRST PART OF
THE EXTENDED FORECAST PERIOD. SUNDAY WILL FEATURE A WAVE OF ENERGY
JUST TO THE EAST AND WARM/MOIST AIR OUT AHEAD. THIS WILL LEAD TO
AFTERNOON SHOWERS AND THUNDERSTORMS FOR SUNDAY. THESE STORMS
HOWEVER WILL HAVE LITTLE UPPER LEVEL SUPPORT WITH LITTLE TO NO
SHEAR...GIVEN THIS THE MAIN THREAT HERE WOULD BE HEAVY RAINFALL
AND QUASISTATIONARY STORMS. THESE STORMS WILL MOSTLY DIE OFF WITH
DAYTIME HEATING. ONCE WE MOVE INTO MONDAY THE UPPER LEVEL TROUGH
WILL NEGATIVELY TILT AND CUTOFF ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY AND GREAT LAKES. THIS WILL USHER IN HEIGHT FALLS AND
HELP SWEEP A COLD FRONT ACROSS THE OHIO VALLEY. THE QUESTION WILL
BE HOW DOES THE LIFT LINE UP WITH THE MODERATELY UNSTABLE
ENVIRONMENT AND BETTER SHEAR. RIGHT NOW THE SETUP WOULD LEAN
TOWARD A SQUALL LINE TYPE MODE...HOWEVER THIS WILL HAVE TO BE
LOOKED AT IN SUBSEQUENT FORECAST UPDATES. DID CONTINUE TO BRING
POPS UP ON MONDAY IN ASSOCIATION WITH PASSING FRONTAL BOUNDARY.
IN THE WAKE OF THE COLD FRONT WILL LEAD TO COOLER AND DRIER
CONDITIONS ACROSS THE REGION TUESDAY INTO MUCH OF THE REST OF THE
EXTENDED. HIGH TEMPERATURES ARE EXPECTED TO BE NEAR TO EVEN BELOW
NORMAL. WINDS WILL START OF OUT OF THE WEST/NORTHWEST TO EAST OVER
THROUGH THE REST OF THE PERIOD...AS HIGH PRESSURE DROPS SOUTHEAST
OF OF THE GREAT LAKES. GUIDANCE SUGGESTS OVERRUNNING PRECIP WILL
COME BACK INTO THE PICTURE AS WE MOVE TOWARD FRIDAY. RIGHT NOW
FORECAST SOUNDINGS WOULD SUGGEST LACK OF THUNDER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 124 AM EDT SAT MAY 9 2015
VFR CONDITIONS WILL START THE TAF PERIOD. SOME VALLEY FOG WILL
DEVELOP OVERNIGHT. BASED ON HOW VISIBILITIES HAVE RESPONDED THE
PAST FEW NIGHTS...WILL CONTINUE TO MENTION SOME LIGHT FOG AT A FEW
OF THE TAF SITES LATE TONIGHT WITH A QUICK RETURN TO VFR AFTER
SUNRISE AS THE FOG BURNS OFF. VFR CONDITIONS WILL THEN CONTINUE
THROUGH THE REMAINDER OF THE PERIOD. THE ONLY CONCERN WILL AGAIN
BE THE POTENTIAL FOR AN ISOLATED THUNDERSTORM JUST ABOUT ANYWHERE
ACROSS EASTERN KENTUCKY SATURDAY AFTERNOON AND EVENING.
HOWEVER...LOW CONFIDENCE WILL KEEP THE MENTION OUT OF THE TAFS FOR
NOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1037 PM CDT SUN MAY 10 2015
.UPDATE...
SOME CHANGES TO TEMPERATURES...POPS...WEATHER AND SKY
&&
.DISCUSSION...
MODELS LAGGING BOTH NEW NAM AND LATEST HRRR. WE HAVE GONE WITH
OBSERVATION AND EXPECTATION FOR THIS DEVELOPING SQUALL LINE THAT
IS COMING TOGETHER OVER SE OK/SW AR AND NE TX. NEW WPC QPF MATCHES
WELL. CLOUDY WORDING IS RIGHT ON UNDER ALL THIS ANVIL DIVERGENCE
AND WE HAVE BUMPED TEMPERATURES AND TWEAKED LOWS. THE WATER VAPOR
IS SHOWING THE PARENT LOW SPOKING NEGATIVE INTO THE MIDWEST WITH
ANOTHER VORT OVER CO DROPPING INTO THE PATTERN NOW. THIS WILL
ASSIST THE PUSH ACROSS OVERNIGHT BY TAKING THE VENTING EASTWARD
KEEPING THE CONVECTIVE OUTFLOW IN BUSINESS. THE COLD FRONT LOOKS
TO BE CLOSE TO TRACK WITH LIKELY MORE WEATHER...BUT WITH A BIT
LESS OVERALL WIND ON THE ALL BLEND DURING LATE MONDAY AND
EVENING. ANOTHER UPDATE WITH OR WITHOUT A NEW WATCH BY MIDNIGHT.
/24/
&&
.PREV DISCUSSION... /ISSUED 805 PM CDT SUN MAY 10 2015/
UPDATE...
TO ADD NEW TORNADO WATCH 161 HEADLINE VALID UNTIL MIDNIGHT
DISCUSSION...
SEVERE THUNDERSTORMS ARE ON GOING IN SE OK/SW AR AND INCHING
EASTWARD ACROSS NE TX. THERE IS A GREAT DEAL OF FORCING UNDER
UPPER LEVEL DIVERGENCE AS THE PARENT UPPER LOW OVER SD/NB IS
NEGATIVELY TILTING ALONG WITH GRANTED LIGHT SURFACE WINDS...BUT
STILL BACKING TO E AND SE AREA WIDE. OUR CURRENT SOUNDING IS
SHOWING GOOD TURNING TO SW BY 850 MB OR ABOUT 5000 THOUSAND FEET.
HOPEFULLY AS THE SUNSETS WE WILL LOOSE SOME INSTABILITY. THIS MAY
ALLOW COVERAGE AND EVOLUTION OF ADDITIONAL DEVELOPMENT TO LESSEN.
HOWEVER...THIS WATCH SHOULD DO WELL AS HRRR IS SHOWING A GOOD
SQUALL LINE DEVELOPING SHORTLY AFTER MIDNIGHT. THIS WILL LESSEN
OUR TORNADIC THREAT...BUT INCREASE OUR STRAIGHT LINE LIKELIHOOD
FOR THE OVERNIGHT. NO OTHER CHANGES AT THIS TIME. /24/
PREV DISCUSSION... /ISSUED 654 PM CDT SUN MAY 10 2015/
AVIATION...
MOSTLY VFR ACROSS CWA EARLY THIS EVE...BUT ISOLD CONVECTION
BEGINNING TO INCREASE. SHRA VCNTY KELD...KLFK...AND KGGG
ATTM. MOVMT NWD NEAR 30 KTS. STG TO SVR TSTMS WILL INCREASE FROM
WEST BY AROUND 11/02Z INTO NE TX AND POSSIBLY KTXK AND KSHV. VERY
FQT LTG...LARGE HAIL POSSIBLE IN ROTATING STORMS. ADDITIONAL
STORMS EARLY MONDAY WITH COLD FRONT ENTERING AREA. SFC WINDS SOUTH
5 TO 10 KTS TONIGHT...BECMG W/NW AROUND 5 KTS WITH FRONT./VII/.
PREV DISCUSSION... /ISSUED 345 PM CDT SUN MAY 10 2015/
DISCUSSION...
AXIS OF DEEP CONVECTION HAS SHIFTED LITTLE...AS EASTWARD
PROGRESSION INTO DRIER AND MORE STABLE AIR HAS BEEN SLOW TO
OCCUR...AND 700 MB FLOW HAS BEEN NEARLY PARALLEL TO ORIENTATION OF
STORMS. THUS...SPC HAS MERGED TO SEPARATE TORNADO WATCHES INTO ONE
ENTITY...IN EFFECT UNTIL 02Z. COLD FRONT STILL JUST EAST OF TX
PANHANDLE...SO SVR THREAT COULD CONTINUE BEYOND THAT. HAVE LEFT IN
SVR MENTION THRU THE OVERNIGHT....AND TSTM DEVELOPMENT SOUTH OF
I-30 STILL EXPECTED DURG THE DAY MONDAY. AFTER THIS...NAM BRINGING
FRONT THRU QUICKER THAN GFS...CLEARLY EVIDENT BY MOS TEMP
DIFFERENCES EXCEEDING 10 DEGREES ON HIGH TEMPS TUESDAY. THE FRONT
ORIENTATIN WILL AFFECT DETAILS OF FCST THROUGHOUT THE
WEEK...HOWEVER...GENERALLY HIGHER POPS SEEN OVER WESTERN...AND
ESPECIALLY SOUTHERN PORTIONS OF CWA FOR MOST OF THE WEEK./VII/.
PREV DISCUSSION... /ISSUED 137 PM CDT SUN MAY 10 2015/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 72 83 61 75 / 80 70 20 30
MLU 73 83 65 78 / 50 70 20 40
DEQ 63 79 59 72 / 80 30 10 10
TXK 68 81 62 73 / 80 50 10 20
ELD 70 81 65 74 / 80 70 20 20
TYR 69 80 61 74 / 80 50 20 30
GGG 72 82 61 74 / 80 70 20 30
LFK 73 83 67 76 / 70 70 40 60
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR ARZ050-051-059>061-
070>073.
LA...NONE.
OK...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR OKZ077.
TX...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR TXZ096-097-108>112.
&&
$$
24/07/07
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
805 PM CDT SUN MAY 10 2015
.UPDATE...
TO ADD NEW TORNADO WATCH 161 HEADLINE VALID UNTIL MIDNIGHT
&&
.DISCUSSION...
SEVERE THUNDERSTORMS ARE ON GOING IN SE OK/SW AR AND INCHING
EASTWARD ACROSS NE TX. THERE IS A GREAT DEAL OF FORCING UNDER
UPPER LEVEL DIVERGENCE AS THE PARENT UPPER LOW OVER SD/NB IS
NEGATIVELY TILTING ALONG WITH GRANTED LIGHT SURFACE WINDS...BUT
STILL BACKING TO E AND SE AREA WIDE. OUR CURRENT SOUNDING IS
SHOWING GOOD TURNING TO SW BY 850 MB OR ABOUT 5000 THOUSAND FEET.
HOPEFULLY AS THE SUNSETS WE WILL LOOSE SOME INSTABILITY. THIS MAY
ALLOW COVERAGE AND EVOLUTION OF ADDITIONAL DEVELOPMENT TO LESSEN.
HOWEVER...THIS WATCH SHOULD DO WELL AS HRRR IS SHOWING A GOOD
SQUALL LINE DEVELOPING SHORTLY AFTER MIDNIGHT. THIS WILL LESSEN
OUR TORNADIC THREAT...BUT INCREASE OUR STRAIGHT LINE LIKELIHOOD
FOR THE OVERNIGHT. NO OTHER CHANGES AT THIS TIME. /24/
&&
.PREV DISCUSSION... /ISSUED 654 PM CDT SUN MAY 10 2015/
AVIATION...
MOSTLY VFR ACROSS CWA EARLY THIS EVE...BUT ISOLD CONVECTION
BEGINNING TO INCREASE. SHRA VCNTY KELD...KLFK...AND KGGG
ATTM. MOVMT NWD NEAR 30 KTS. STG TO SVR TSTMS WILL INCREASE FROM
WEST BY AROUND 11/02Z INTO NE TX AND POSSIBLY KTXK AND KSHV. VERY
FQT LTG...LARGE HAIL POSSIBLE IN ROTATING STORMS. ADDITIONAL
STORMS EARLY MONDAY WITH COLD FRONT ENTERING AREA. SFC WINDS SOUTH
5 TO 10 KTS TONIGHT...BECMG W/NW AROUND 5 KTS WITH FRONT./VII/.
PREV DISCUSSION... /ISSUED 345 PM CDT SUN MAY 10 2015/
DISCUSSION...
AXIS OF DEEP CONVECTION HAS SHIFTED LITTLE...AS EASTWARD
PROGRESSION INTO DRIER AND MORE STABLE AIR HAS BEEN SLOW TO
OCCUR...AND 700 MB FLOW HAS BEEN NEARLY PARALLEL TO ORIENTATION OF
STORMS. THUS...SPC HAS MERGED TO SEPARATE TORNADO WATCHES INTO ONE
ENTITY...IN EFFECT UNTIL 02Z. COLD FRONT STILL JUST EAST OF TX
PANHANDLE...SO SVR THREAT COULD CONTINUE BEYOND THAT. HAVE LEFT IN
SVR MENTION THRU THE OVERNIGHT....AND TSTM DEVELOPMENT SOUTH OF
I-30 STILL EXPECTED DURG THE DAY MONDAY. AFTER THIS...NAM BRINGING
FRONT THRU QUICKER THAN GFS...CLEARLY EVIDENT BY MOS TEMP
DIFFERENCES EXCEEDING 10 DEGREES ON HIGH TEMPS TUESDAY. THE FRONT
ORIENTATIN WILL AFFECT DETAILS OF FCST THROUGHOUT THE
WEEK...HOWEVER...GENERALLY HIGHER POPS SEEN OVER WESTERN...AND
ESPECIALLY SOUTHERN PORTIONS OF CWA FOR MOST OF THE WEEK./VII/.
PREV DISCUSSION... /ISSUED 137 PM CDT SUN MAY 10 2015/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 72 83 61 75 / 80 70 20 30
MLU 72 83 65 78 / 50 70 20 40
DEQ 61 79 59 72 / 80 30 10 10
TXK 68 81 62 73 / 80 40 10 20
ELD 71 81 65 74 / 80 70 20 20
TYR 70 80 61 74 / 80 40 20 30
GGG 72 82 61 74 / 80 70 20 30
LFK 72 83 67 76 / 70 60 40 60
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR ARZ050-051-059>061-
070>073.
LA...NONE.
OK...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR OKZ077.
TX...FLASH FLOOD WATCH UNTIL 7 AM CDT MONDAY FOR TXZ096-097-108>112.
&&
$$
24/07/07
AREA FORECAST DISCUSSION
NWS CARIBOU ME
607 AM EDT SAT MAY 9 2015
.SYNOPSIS...
A WARM FRONT WILL SLOWLY CROSS THE REGION TODAY. A COLD FRONT
WILL APPROACH NORTHERN AREAS THIS EVENING...THEN SLOWLY CROSS THE
REGION LATE TONIGHT THROUGH SUNDAY. THIS FRONT WILL STALL OVER THE
SOUTHERN GULF OF MAINE ON MON...THEN MOVE BACK TO THE NORTH AS A
WARM FRONT ON TUESDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
600 AM UPDATE: BASED ON THE LATEST FCST HRLY SIM RADAR REF FROM
THE HRRR MODEL...WE MOVED BACK THE ONSET TMG OF SHWRS ACROSS THE
N ABOUT TWO HRS OR SO. THIS IN EFFECT...TOOK ANY MENTION OF MRNG
SHWRS OUT OF THE FCST...SPCLY OVR NW AND FAR NE ME. OTHERWISE...
MINOR CHGS TO FCST HRLY TEMPS TDY TO UNCHGD FCST HI TEMPS AT 4-5
PM EDT BASED OBSVD TEMPS AT 5-6 AM EDT. LASTLY...WE REDUCED CLD
CVR FOR ERLY TO MID MRNG A LITTLE OVR NE...CNTRL AND DOWNEAST ME
BASED ON LATEST TRENDS FROM SAT IMAGERY.
ORGNL DISC: TEMPS OVR DOWNEAST AREAS HAS BEEN TRICKY VERY ERLY
THIS MORN...WITH CLR SKIES OVR SPCLY WASHINGTON COUNTY ALLOWING
TEMPS TO FALL BLO PREV FCST LOWS. IN ADDITION...THE LEADING EDGE
OF BKN-OVC SC IS JUST WEST OF THIS PTN OF THE FA...AND SHOULD MAKE
SOME HEADWAY INTO DOWNEAST AREAS BY SUNRISE. OTHERWISE...GENERAL
MID CLDNSS SHOULD MOVE BACK OVR THE FA FROM QB PROV AS A WEAK S/WV
ALF TOPS THE MEAN UPPER RIDGE OVR THE MID ATLC AND SRN NEW ENG
STATES. THIS SYSTEM WILL BRING SHWRS INITIALLY TO NRN PTNS OF THE
FA LATER THIS AFTN INTO TNGT...THAN ACROSS CNTRL AND DOWNEAST
AREAS ON SUN AS AN ACCOMPANYING COLD FRONT SLOWLY MOVES SWRD
ACROSS THE FA BEGINNING LATE TNGT ACROSS THE FAR NW AND MOVING
INTO THE GULF OF ME SUN EVE.
WEAK ELEVATED CAPE MAY RESULT IN ISOLATED TSTMS TO NW PTNS OF THE
FA LATE THIS AFTN INTO MID EVE...OTHERWISE...MORE IN THE WAY OF
SBCAPE AHEAD OF THE COLD FRONT WILL BRING A BETTER CHC OF TSTMS
TO CNTRL AND DOWNEAST PTNS OF THE FA SUN AFTN AS THE FRONT MAKES
SLOW SSE PROGRESS OVR THESE PTNS OF THE FA. SYNOPTIC RAINFALL
AMOUNTS WILL RANGE FROM ARND A QUARTER INCH OVR COASTAL DOWNEAST
PTNS OF THE REGION...WITH LCLY HIGHER TOTALS IN THE VICINITY OF
ANY TSTMS SUN AFTN...UPWARDS TO 0.75 INCHES OVR THE NW (MOST OF
WHICH OVR THIS PTN OF THE FA FALLING LATE THIS AFTN INTO TONIGHT.
HIGH TEMPS THIS AFTN WILL BE ABOUT 5 TO 10 DEG WARMER THAN
YSTDY...SPCLY OVR WRN PTNS OF THE FA AS LLVL WARM AIR BEGINS TO
RETURN WITH THE ARRIVAL OF THE WARM FRONT...WITH EVEN WARMER HI
TEMPS SUN OVR CNTRL AND SPCLY DOWNEAST AREAS AHEAD OF THE COLD
FRONT SUN AFTN AFT MILD OVRNGT LOWS SAT NGT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
CDFNT WL EVENTUALLY MV THRU CWA EARLY IN THE SHORT TERM AND LKLY
STALL OUT ALONG THE COAST BY 12Z MONDAY. LATEST MEDIUM RANGE
GUIDANCE INDICATES HIPRES BUILDING IN BRIEFLY FM CANADA WITH
SHOWERS LIKELY WANING LATE SUN NGT, THO BNDRY IN CLOSE PROXIMITY
TO COASTAL ZONES WARRANTS KEEPING LOCHC POPS THRU PD. EXPECT MIN
TEMPS SUN NGT TO RMN ABV NORMAL - RANGING FM M40S ACRS THE NORTH
TO LOW 50S FOR DOWNEAST AREAS.
STALLED FRONTAL BNDRY WL BEGIN TO LIFT BACK NORTH AS A WMFNT DRG
THE DAY MONDAY AS H5 TROF DIGS INTO THE NRN PLAINS WITH SFC LOW
INTENSIFYING ACRS UPR MIDWEST BRINGING STRONG SRLY FLOW TO ERN
U.S. EXPECT RAIN TO FALL OVR CWA THRU END OF SHORT TERM. SFC LOW
WL LKLY TRACK THRU MAINE TUE EVNG WIT
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
EXPECT RAIN TO CONTINUE THRU THE MIDDLE OF THE WEEK BFR LOW
EJECTS OFF TO THE EAST WED NGT. SFC HIPRES WL BUILD IN THRU THE
END OF THE WEEK WITH MODERATING TEMPS EXPECTED UNDER BUILDING
HEIGHTS. APPEARS AS THO END OF WEEK AND EARLY IN THE WEEKEND WL
FEATURE TEMPS BACK INTO THE 70S.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: MVFR AND PERHAPS BRIEF IFR IS EXPECTED OVER THE
DOWNEAST TAF SITES THIS MORN...WITH SOME IMPROVEMENT INLAND FROM
THE IMMEDIATE COAST. OTHERWISE...VFR ACROSS NRN TAF SITES WILL
TRANSITION TO MVFR CLGS AND PERHAPS VSBYS BY EVE WITH THE ARRIVAL
OF SHWRS WITH IFR CLGS AND VSBYS POSSIBLE ALL TAF SITES WITH
ADDITIONAL SHWRS AND PATCHY FOG LATE TNGT. IFR CONDITIONS ALL TAF
SITES SUN MORN SHOULD IMPROVE TO AT LEAST MVFR CONDITIONS BY SUN
AFTN.
SHORT TERM: MAINLY VFR EXPECTED THROUGH MONDAY MORNING THEN
DIMINISHING TO MVFR/IFR IN RAIN THROUGH THE MIDDLE OF THE WEEK.
&&
.MARINE...
NEAR TERM: NO HDLNS ANTICIPATED THRU SUN...WITH MARINE FOG
BECOMING MORE OF AN ISSUE SAT NGT THRU SUN AS WARMER AND MORE
HUMID AIR FROM THE SSW STREAMS NWRD OVR THE COLD GULF OF ME
WATERS. KEPT CLOSE TO AND SLGTLY BLO WW3 WV GUIDANCE THRU THIS
PTN OF THE FCST.
SHORT TERM: SMALL CRAFT ADVISORY FOR SEAS COULD DEVELOP SUNDAY
NIGHT, IMPROVING EARLY IN THE WEEK. ADDITIONAL SMALL CRAFT
CONDITIONS WILL BE POSSIBLE ON TUESDAY INTO THE MIDDLE OF THE
WEEK.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...VJN
SHORT TERM...FARRAR
LONG TERM...FARRAR
AVIATION...VJN/FARRAR
MARINE...VJN/FARRAR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
802 PM EDT SUN MAY 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 732 PM EDT SUN MAY 10 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. LOW PRES SYSTEM
MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER
LAKES...MAINLY LATE TONIGHT/MON MORNING. WHILE KSAW AND KCMX MAY
REMAIN MVFR TONIGHT PRIOR TO THE ARRIVAL OF PCPN...VFR CONDITIONS
COULD LINGER THIS EVENING AT KIWD. WITH THE ARRIVAL OF THE -SHRA...
EXPECT A TREND DOWN THRU MVFR TO IFR MON MORNING AT ALL TERMINALS.
UPSLOPE E-NE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING
AT KCMX/KSAW BY LATE MORNING. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT MONDAY FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 431 PM EDT SAT MAY 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW AN AMPLIFIED RIDGE ALONG
THE W COAST OF NAMERICA. DOWNSTREAM...TROF EXTENDS FROM HUDSON BAY
TO THE SRN ROCKIES. ENERGY IN THE TROF IS SPLIT WITH THE NRN STREAM
PORTION EXTENDING AS FAR S AS MT/ND. FARTHER S...VIGOROUS MID LEVEL
LOW IN THE SRN STREAM PORTION OF THE TROF IS CENTERED NEAR THE 4
CORNERS. CLOSER TO HOME...LOW CLOUDS HAVE DOMINATED MUCH OF THE FCST
AREA TODAY...THOUGH IN THE LAST COUPLE OF HRS...SATELLITE IMAGERY
SHOWS HIGH EARLY MAY SUN ANGLE BEGINNING TO MIX OUT THE MOISTURE
FROM THE EDGES. CLOUDS AND -DZ ARE HOLDING TOUGH OVER NCNTRL UPPER
MI WHERE STRONGEST UPSLOPE IS OCCURRING.
FCST IN THE SHORT TERM WILL REVOLVE AROUND CLOUD TRENDS TONIGHT AND
THEN POTENTIAL OF -SHRA SUN AS MID LEVEL LOW LIFTS INTO SD/NEBRASKA
WITH WEAK LEAD ENERGY EJECTING INTO THE WRN GREAT LAKES.
OF IMMEDIATE CONCERN IS THE LOW CLOUDS AND PATCHY -DZ. SEVERAL MORE
HRS OF DAYTIME HEATING WILL CONTINUE TO EAT AWAY AT THE LOW CLOUDS
FROM THE EDGES...BUT HAVE LOW CONFIDENCE IN ALL OF THE CLOUDS
DISSIPATING OVER NCNTRL UPPER MI. INCREASINGLY DIFFLUENT LOW-LEVEL
FLOW OVER THE LAKE AS LAKE BREEZE CIRCULATION CONTINUES TO INCREASE
FOR A FEW MORE HRS WILL ALSO WORK TO AID CLEARING. FOR NOW...FCST
WILL REFLECT AN OPTIMISTIC TREND LATE AFTN/EARLY EVENING. AS A
RESULT...FAVORED THE LOWER SIDE OF GUIDANCE FOR MINS TONIGHT...
ESPECIALLY W AND WELL INTO THE INTERIOR OVER THE CNTRL WHERE SKIES
ARE LIKELY TO HAVE LEAST CLOUDINESS FOR THE LONGEST PERIOD.
TRADITIONAL COLD SPOTS MAY FALL TO FREEZING. GIVEN THE ABUNDANCE OF
LOW CLOUDS NE AND E OF LAKE SUPERIOR...MAY SEE LOW CLOUDS INCREASE
AGAIN LATE IN THE NIGHT OVER THE CNTRL AND E AS LOW-LEVEL NE
FLOW CONTINUES.
IF LOW CLOUDS REDEVELOP INTO NCNTRL UPPER MI LATE TONIGHT...MAY HAVE
A REPEAT PERFORMANCE OF PATCHY -DZ SUN MORNING. OTHERWISE...THE
TREND FROM ALL MODELS IS DEFINITELY FOR A DRIER LOOK ON SUN WITH
SHORTWAVE SWINGING NE INTO THE GREAT LAKES AHEAD OF MAIN SYSTEM
MOVING OUT OVER THE WRN PLAINS. SHORTWAVE IN QUESTION IS AIDING
CONVECTION CURRENTLY OVER THE SRN PLAINS. MODELS INDICATE TRACK OF
THIS SHORTWAVE PASSING TO THE SE OF HERE. GIVEN THE LACK OF DEEP
LAYER FORCING AND MUCH WEAKER ISENTROPIC ASCENT ACROSS THE FCST AREA
COMPARED TO PREVIOUS MODEL RUNS...THE DRIER TREND APPEARS
REASONABLE. HAVE SCALED BACK POPS CONSIDERABLY FOR SUN WITH SCHC
POPS ONLY OVER THE SCNTRL IN THE AFTN. WITH THE A DRIER FCST...
RAISED MAX TEMPS SLIGHTLY. EXPECT MOSTLY 40S NEAR LAKE SUPERIOR...
50S INLAND. MAY REACH 60F IN A FEW SPOTS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM EDT SAT MAY 9 2015
RAIN ASSOCIATED WITH AN UPPER SHORTWAVE AND SFC LOW WILL MOVE INTO
THE AREA FROM THE SW SUN NIGHT AND CONTINUE INTO MON. AS THE SFC LOW
SHIFTS ACROSS THE AREA MON EVENING INTO MON NIGHT...SHIFTING A DRY
SLOT ACROSS MOST OF THE CWA. THIS WILL DIMINISH THE RAIN UNTIL
MOISTURE MOVES BACK IN FROM THE W ON THE BACK SIDE OF THE SYSTEM
LATE MON NIGHT INTO TUE. MUCH COLDER AIR SURGES IN ON TUE WITH 850MB
TEMPS DROPPING TO AROUND -15C OVER AT LEAST NWRN UPPER MI BY 00Z
WED. THIS WILL SUPPORT A CHANGE OVER TO MIXED PRECIP OVER THE
NRN/NWRN PORTIONS OF UPPER MI ON TUE AND MOSTLY SNOW TUE NIGHT. THE
FORCING TUE INTO TUE NIGHT WILL COME FROM BOTH THE WRAP AROUND FROM
THE LOW AND FROM A WEAK SHORTWAVE MOVING IN FROM THE NW...WITH ONLY
LIGHT PRECIP EXPECTED AND LITTLE TO NO SNOW ACCUMULATION.
MON WILL SEE HIGHS IN THE 50S INLAND FROM LAKE SUPERIOR AND IN THE
40S ALONG THE BIG LAKE. TUE LOOKS TO BE THE COLDEST DAY OF THE WEEK
WITH HIGHS BARELY REACHING 50F OVER THE SCENTRAL AND IN THE 40S
ELSEWHERE. IT WILL ALSO BE CLOUDY AND BREEZY MAKING IT FEEL EVEN
COLDER. TEMPS WILL BE TRICKY TUE NIGHT AS CLOUDS WILL BE CLEARING
AND THE COLDER AIRMASS REMAINS. SHOULD SEE LOWS NEAR OR BELOW
FREEZING WITH THE CURRENT EXPECTATION OF CLOUDS CLEARING BY SUNRISE
WED...BUT MUCH COLDER TEMPS ARE POSSIBLE IF THE CLOUDS CLEAR EARLIER.
THE AIRMASS WILL BEGIN TO MODERATE ON WED AS 850MB TEMPS INCREASE TO
AROUND 0C BY 00Z THU WITH A 1031MB SFC HIGH MOVING OVER THE CWA.
SHOULD BE AN OVERALL PLEASANT DAY WITH SUNNY SKIES...LIGHT WINDS AND
HIGHS IN THE 50S INLAND TO UPPER 40S RIGHT ALONG LAKE SUPERIOR.
SIGNIFICANT UNCERTAINTY EXISTS IN THE THU-SAT PORTION OF THE
FORECAST AS MODELS CONTINUITY AND AGREEMENT IS POOR. THE GENERAL
IDEA IS UPPER RIDGING BUILDING INTO OR NEAR THE REGION...PROMOTING
WARMER TEMPS. RAIN CAN NOT BE RULED OUT. LET CONSENSUS OF GUIDANCE
HANDLE THIS PART OF THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 126 PM EDT SAT MAY 9 2015
LOW CLOUDS HAVE BEEN SLOW TO BREAK UP SO FAR TODAY...BUT SATELLITE
IMAGERY SHOWS THAT DAYTIME HEATING IS BEGINNING TO MIX OUT SOME OF
THE MOISTURE. AT KIWD...CIGS HAVE ALREADY LIFTED ABOVE 3000FT.
EXPECT VFR CONDITIONS TO PREVAIL THERE THRU THE REMAINDER OF THE
FCST PERIOD. AT KCMX...MVFR CIGS WILL SCATTER OUT TO VFR IN THE NEXT
HR OR SO. VFR CONDITIONS SHOULD THEN CONTINUE THRU THE REMAINDER OF
THE FCST PERIOD. HOWEVER...THERE IS SOME CONCERN THAT AS LOW-LEVEL
WINDS VEER TO A MORE EASTERLY UPSLOPE DIRECTION LATER TONIGHT/SUN
MORNING...MVFR CIGS MAY REDEVELOP. AT KSAW...MVFR CIGS WILL LIKELY
CONTINUE FOR A FEW MORE HRS BEFORE SCATTERING OUT...THOUGH
CONFIDENCE IN THE IMPROVEMENT IS LOW. IF LOW CLOUDS DO NOT SCATTER
OUT BY LATE AFTN...MVFR CIGS WILL LIKELY LINGER THRU THE ENTIRE FCST
PERIOD UNDER AN UPSLOPE WIND. IF THEY DO SCATTER OUT AS CURRENTLY
FCST...MVFR CIGS WILL LIKELY RETURN LATE TONIGHT/SUN MORNING AS
UPSLOPE FLOW TAKES ON A MORE CYCLONIC CURVATURE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 431 PM EDT SAT MAY 9 2015
PRES GRADIENT WILL BE TIGHTENING OVER THE UPPER LAKES DURING THE
NEXT 24-48HRS AS HIGH PRES REMAINS ACROSS MANITOBA/NRN ONTARIO AND
LOW PRES MOVES NE ACROSS THE PLAINS. AS A RESULT NE TO E WINDS WILL
BE ON THE INCREASE ACROSS LAKE SUPERIOR. THE INCREASE IN WINDS WILL
BE MOST NOTABLE OVER THE WRN PORTION OF THE LAKE WHERE COASTAL
CONVERGENCE/FUNNELING AND PERSISTENT PRES FALLS TO THE SW WILL
ENHANCE THE WINDS. EXPECT ENE WINDS TO REACH GALE FORCE OVER
PORTIONS OF WRN LAKE SUPERIOR LATE MORNING/EARLY AFTN ON SUN AND
THEN CONTINUE THRU MON AFTN BEFORE DIMINISHING MON EVENING AS THE
LOW SHIFTS E OF THE AREA/WINDS BACK AND PRES GRADIENT WEAKENS.
ACROSS THE REST OF LAKE SUPERIOR...WINDS WILL INCREASE TO 15-25KT
SUN AND TO 20-30KT SUN NIGHT/MON. WINDS WILL THEN DECREASE FROM W TO
E TUE/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS THRU THU.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 11 AM EDT /10 AM CDT/ SUNDAY TO 8 PM EDT /7 PM
CDT/ MONDAY FOR LSZ162.
GALE WARNING FROM 11 PM SUNDAY TO 8 PM EDT MONDAY FOR LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
333 PM EDT SAT MAY 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SAT MAY 9 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH
EXTENDING FROM HUDSON BAY TO A CLOSED LOW OVER UT/AZ RESULTING IN SW
FLOW FROM THE SRN PLAINS TO THE WRN LAKES. AT THE SFC...HIGH PRES
BUILDING TOWARD THE AREA FROM MANITOBA HAS PUSHED THE COLD FRONT
THROUGH NRN LOWER MI LEAVING NRLY FLOW ACROSS LAKE SUPERIOR AND
UPPER MI. AN AREA OF SHOWERS ASSOCIATED WITH A SHORTWAVE TROUGH
CLOSER TO THE FRONT WAS MOVING FROM NRN LAKE MI INTO FAR NRN LOWER
MI. LOW LEVEL MOISTURE COMBINED WITH UPSLOPE FLOW THAT HAD PRODUCED
SOME PATCHY LIGHT DRIZZLE OVER N CNTRL UPPER MI AROUND 06Z
DISSIPATED AS THE LOWER MOISTURE HAS THINNED WITH CLIMBING/THINNING
CIGS NEAR 4K FT.
TODAY...SOME ADDITIONAL PATCHY DRIZZLE NORTH CENTRAL CANNOT BE RULED
OUT IF MORE LOW LEVEL MOISTURE MOVES IN OFF OF LAKE SUPERIOR. BUT
THIS SEEMS LESS LIKELY GIVEN THE AMOUNT OF SFC-900 MB DRYING
OVERNIGHT. EXPECT CLOUDS TO LINGER DURING THE MORNING AND GIVE WAY TO
SOME CLEARING IN THE AFTERNOON WITH INCREASED MIXING. EXPECT TEMPS TO
REBOUND INTO THE LOW TO MID 60S SOUTH CENTRAL BUT LINGER IN THE UPPER
40S TO AROUND 50 NORTH WITH NRLY WINDS OFF OF LAKE SUPERIOR.
TONIGHT...EXPECT THE CLOUD COVER TO THIN OUT DURING THE AFTERNOON
AND EVENING ENOUGH FOR RADIATIONAL COOLING THAT WILL ALLOW TEMPS TO
DROP INTO THE MID TO UPPER 30S UNTIL INCREASING CLOUDS LATE. THE
MODELS WERE CONSISTENT IN KEEPING ANY PCPN AHEAD OF THE LOW PRES
MOVING THROUGH THE PLAINS SOUTH AND WEST OF THE CWA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM EDT SAT MAY 9 2015
RAIN ASSOCIATED WITH AN UPPER SHORTWAVE AND SFC LOW WILL MOVE INTO
THE AREA FROM THE SW SUN NIGHT AND CONTINUE INTO MON. AS THE SFC LOW
SHIFTS ACROSS THE AREA MON EVENING INTO MON NIGHT...SHIFTING A DRY
SLOT ACROSS MOST OF THE CWA. THIS WILL DIMINISH THE RAIN UNTIL
MOISTURE MOVES BACK IN FROM THE W ON THE BACK SIDE OF THE SYSTEM
LATE MON NIGHT INTO TUE. MUCH COLDER AIR SURGES IN ON TUE WITH 850MB
TEMPS DROPPING TO AROUND -15C OVER AT LEAST NWRN UPPER MI BY 00Z
WED. THIS WILL SUPPORT A CHANGE OVER TO MIXED PRECIP OVER THE
NRN/NWRN PORTIONS OF UPPER MI ON TUE AND MOSTLY SNOW TUE NIGHT. THE
FORCING TUE INTO TUE NIGHT WILL COME FROM BOTH THE WRAP AROUND FROM
THE LOW AND FROM A WEAK SHORTWAVE MOVING IN FROM THE NW...WITH ONLY
LIGHT PRECIP EXPECTED AND LITTLE TO NO SNOW ACCUMULATION.
MON WILL SEE HIGHS IN THE 50S INLAND FROM LAKE SUPERIOR AND IN THE
40S ALONG THE BIG LAKE. TUE LOOKS TO BE THE COLDEST DAY OF THE WEEK
WITH HIGHS BARELY REACHING 50F OVER THE SCENTRAL AND IN THE 40S
ELSEWHERE. IT WILL ALSO BE CLOUDY AND BREEZY MAKING IT FEEL EVEN
COLDER. TEMPS WILL BE TRICKY TUE NIGHT AS CLOUDS WILL BE CLEARING
AND THE COLDER AIRMASS REMAINS. SHOULD SEE LOWS NEAR OR BELOW
FREEZING WITH THE CURRENT EXPECTATION OF CLOUDS CLEARING BY SUNRISE
WED...BUT MUCH COLDER TEMPS ARE POSSIBLE IF THE CLOUDS CLEAR EARLIER.
THE AIRMASS WILL BEGIN TO MODERATE ON WED AS 850MB TEMPS INCREASE TO
AROUND 0C BY 00Z THU WITH A 1031MB SFC HIGH MOVING OVER THE CWA.
SHOULD BE AN OVERALL PLEASANT DAY WITH SUNNY SKIES...LIGHT WINDS AND
HIGHS IN THE 50S INLAND TO UPPER 40S RIGHT ALONG LAKE SUPERIOR.
SIGNIFICANT UNCERTAINTY EXISTS IN THE THU-SAT PORTION OF THE
FORECAST AS MODELS CONTINUITY AND AGREEMENT IS POOR. THE GENERAL
IDEA IS UPPER RIDGING BUILDING INTO OR NEAR THE REGION...PROMOTING
WARMER TEMPS. RAIN CAN NOT BE RULED OUT. LET CONSENSUS OF GUIDANCE
HANDLE THIS PART OF THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 126 PM EDT SAT MAY 9 2015
LOW CLOUDS HAVE BEEN SLOW TO BREAK UP SO FAR TODAY...BUT SATELLITE
IMAGERY SHOWS THAT DAYTIME HEATING IS BEGINNING TO MIX OUT SOME OF
THE MOISTURE. AT KIWD...CIGS HAVE ALREADY LIFTED ABOVE 3000FT.
EXPECT VFR CONDITIONS TO PREVAIL THERE THRU THE REMAINDER OF THE
FCST PERIOD. AT KCMX...MVFR CIGS WILL SCATTER OUT TO VFR IN THE NEXT
HR OR SO. VFR CONDITIONS SHOULD THEN CONTINUE THRU THE REMAINDER OF
THE FCST PERIOD. HOWEVER...THERE IS SOME CONCERN THAT AS LOW-LEVEL
WINDS VEER TO A MORE EASTERLY UPSLOPE DIRECTION LATER TONIGHT/SUN
MORNING...MVFR CIGS MAY REDEVELOP. AT KSAW...MVFR CIGS WILL LIKELY
CONTINUE FOR A FEW MORE HRS BEFORE SCATTERING OUT...THOUGH
CONFIDENCE IN THE IMPROVEMENT IS LOW. IF LOW CLOUDS DO NOT SCATTER
OUT BY LATE AFTN...MVFR CIGS WILL LIKELY LINGER THRU THE ENTIRE FCST
PERIOD UNDER AN UPSLOPE WIND. IF THEY DO SCATTER OUT AS CURRENTLY
FCST...MVFR CIGS WILL LIKELY RETURN LATE TONIGHT/SUN MORNING AS
UPSLOPE FLOW TAKES ON A MORE CYCLONIC CURVATURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT MAY 9 2015
NNE WINDS UP TO 20 KTS ON THE SOUTHERN FLANK OF HI PRES IN MANITOBA
WILL INCREASE TONIGHT INTO SUN AS THE PRES GRADIENT TIGHTENS OVER
THE UPPER LAKES AHEAD OF A LO PRES MOVING NE TOWARD THE UPPER MS
RIVER VALLEY FROM THE PLAINS. WHERE THE TERRAIN OVER THE W HALF OF
LAKE SUPERIOR ACCENTUATES THIS FLOW...EXPECT NE GALES TO DEVELOP ON
SUN AFTERNOON AND PERSIST THRU MUCH OF MON AFTERNOON BEFORE THE PRES
GRADIENT WEAKENS SUFFICIENTLY TO ALLOW WINDS TO SUBSIDE UNDER GALE
FORCE. ISSUED A GALE WATCH FOR THE TWO WESTERN LAKE ZONES WHERE THE
GALES ARE MOST LIKELY. WINDS WILL THEN DECREASE STEADILY ON TUE INTO
WED AS THE LO SHIFTS TO THE E AND HI PRES APPROACHES FROM THE
NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
LSZ162.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
127 PM EDT SAT MAY 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SAT MAY 9 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH
EXTENDING FROM HUDSON BAY TO A CLOSED LOW OVER UT/AZ RESULTING IN SW
FLOW FROM THE SRN PLAINS TO THE WRN LAKES. AT THE SFC...HIGH PRES
BUILDING TOWARD THE AREA FROM MANITOBA HAS PUSHED THE COLD FRONT
THROUGH NRN LOWER MI LEAVING NRLY FLOW ACROSS LAKE SUPERIOR AND
UPPER MI. AN AREA OF SHOWERS ASSOCIATED WITH A SHORTWAVE TROUGH
CLOSER TO THE FRONT WAS MOVING FROM NRN LAKE MI INTO FAR NRN LOWER
MI. LOW LEVEL MOISTURE COMBINED WITH UPSLOPE FLOW THAT HAD PRODUCED
SOME PATCHY LIGHT DRIZZLE OVER N CNTRL UPPER MI AROUND 06Z
DISSIPATED AS THE LOWER MOISTURE HAS THINNED WITH CLIMBING/THINNING
CIGS NEAR 4K FT.
TODAY...SOME ADDITIONAL PATCHY DRIZZLE NORTH CENTRAL CANNOT BE RULED
OUT IF MORE LOW LEVEL MOISTURE MOVES IN OFF OF LAKE SUPERIOR. BUT
THIS SEEMS LESS LIKELY GIVEN THE AMOUNT OF SFC-900 MB DRYING
OVERNIGHT. EXPECT CLOUDS TO LINGER DURING THE MORNING AND GIVE WAY TO
SOME CLEARING IN THE AFTERNOON WITH INCREASED MIXING. EXPECT TEMPS TO
REBOUND INTO THE LOW TO MID 60S SOUTH CENTRAL BUT LINGER IN THE UPPER
40S TO AROUND 50 NORTH WITH NRLY WINDS OFF OF LAKE SUPERIOR.
TONIGHT...EXPECT THE CLOUD COVER TO THIN OUT DURING THE AFTERNOON
AND EVENING ENOUGH FOR RADIATIONAL COOLING THAT WILL ALLOW TEMPS TO
DROP INTO THE MID TO UPPER 30S UNTIL INCREASING CLOUDS LATE. THE
MODELS WERE CONSISTENT IN KEEPING ANY PCPN AHEAD OF THE LOW PRES
MOVING THROUGH THE PLAINS SOUTH AND WEST OF THE CWA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 442 AM EDT SAT MAY 9 2015
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE WL FOCUS ON POPS/
QPF/PTYPE EARLY THIS COMING WEEK AS CLOSED LO NOW OVER THE DESERT SW
LIFTS NEWD INTO THE UPR LKS. TEMPS WL RUN BLO NORMAL UNTIL AT LEAST
THE MIDDLE OF NEXT WEEK...WHEN THE LONGER TERM GUIDANCE HINTS AN UPR
RDG WL REBOUND INTO THE UPR MS RIVER VALLEY.
SUN...UPR MI WL BE UNDER THE INFLUENCE OF E FLOW ON THE SRN FLANK OF
HI PRES CENTERED OVER FAR NW ONTARIO. THERE REMAIN DIFFERENCES AMONG
THE MODELS AS TO THE EXTENT OF LLVL MSTR/LO CLDS UNDER THE
SUBSIDENCE INVRN...WITH THE BEST CHC OF MORE EXTENSIVE LO CLD OVER
THE HIER TERRAIN OF THE NCENTRAL AND OVER THE SCNTRL WHERE THE LLVL
FLOW WL UPSLOPE. NO MATTER THE EXTENT OF THE LO CLDS...EXPECT INCRSG
HI/MID CLDS AS THE SW FLOW ALF BECOMES MORE DIFFLUENT AHEAD OF
CLOSED LO LIFTING INTO THE NRN PLAINS. AS FOR POPS...THERE ARE SOME
DIFFERENCES ON THE TRACK OF DISTURBANCE RESPONSIBLE FOR AREA OF
CONVECTION NOW OVER OK. THE 00Z REGIONAL CNDN MODEL AND LOCAL WRF-
ARW SHOW THIS DISTURBANCE MOVING INTO LOWER MI AND FAR ENUF TO THE
NW TO BRING AT LEAST SOME -SHRA TO THE SE CWA MUCH OF THE DAY. OTHER
GUIDANCE...ESPECIALLY RECENT GFS RUNS...SHOW A WEAKER DISTURBANCE
LIFTING NEWD INTO THE UPR LKS WELL IN ADVANCE OF THE MAIN SHRTWV.
BUT SINCE THIS DISTURBANCE TENDS TO OUTRUN THE MORE SGNFT DYNAMIC
FORCING AHEAD OF THE MAIN SHRTWV HANGING BACK WELL TO THE W...WL
FCST NO HIER THAN CHC POPS.
SUN NGT THRU MON NGT...AS CLOSED LO IN THE NRN PLAINS LATE ON SUN
OPENS UP AND DRIFTS INTO THE UPR LKS BY 12Z TUE...ACCOMPANYING SFC
LO IS FCST TO MOVE E FM MN ACRS SCENTRAL UPR MI TO A POINT E OF THE
SAULT BY 12Z TUE. THE TRACK OF THESE FEATURES AND INTERACTION BTWN
ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1
INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS.
OVERALL...THE MODELS TRACK THE SHRTWV/ACCOMPANYING SFC LO FAR ENUF
TO THE N TO SHOW THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETTING UP
TO THE N OF UPR MI. IN THIS SCENARIO...THE WARM CONVEYOR BELT MSTR
RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN
FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST
TO IMPACT MAINLY THE CENTRAL AND ERN CWA FM LATE SUN NGT THRU MON
MRNG...SO FCST WL SHOW THE HIER QPF AND MORE PERSISTENT HIER POPS IN
THAT AREA DURING THAT TIME. BY LATER ON MON...A GOOD NUMBER OF THE
MODELS INDICATE SOME DRY SLOTTING AHEAD OF THE APRCHG SHRTWV WL
IMPACT ALL BUT THE FAR NRN CWA...SO WL LOWER POPS DURING THIS
PERIOD. GIVEN THE TRACK OF THE FEATURES OF INTEREST...MAINTAINED A
SCHC FOR ELEVATED TS N OVER PORTIONS OF THE SCNTRL CWA. ONCE THE
SHRTWV BEGINS TO SHIFT FASTER TO THE E ON MON NGT...AREA OF DEEPER
MSTR/SHARPER DEEP LYR QVECTOR CNVGC TO THE W SHOULD EXPAND INTO THE
CWA AND BRING A RETURN OF MORE NMRS SHOWERS W TO E WITHIN LINGERING
FAIRLY SHARP LLVL CYC FLOW.
TUE...AS THE SHRTWV/SFC LO EXIT TO THE E...DNVA/DEEP LYR QVECTOR
DVGC UNDER RISING HGTS SHOULD CAUSE A LOWERING OF THE POPS DESPITE
LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE
UPSLOPE AREAS OVER THE NRN TIER IMPACTED BY THE N WIND LEFT IN THE
WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR
WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE
SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME
INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM
EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO
NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN
AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA AND END LINGERING PCPN. IF SKIES CLR...
MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF
CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER.
WED THRU FRI...ALTHOUGH UPR RDG/SFC HI PRES ARE FCST TO BLD OVER THE
GRT LKS ON WED FOLLOWING THE EXIT OF THE LO PRES TO THE E...THE 00Z
ECWMF AND ESPECIALLY THE 00Z GFS SHOW A DISTURBANCE RIDING OVER THE
TOP OF THE RDG INITIATING AN AREA OF SHOWERS TO THE NE OF AN H85
WARM FNT DVLPG IN THE UPR MS RIVER VALLEY AND OVERSPREADING AT LEAST
A PORTION OF THE CWA WED NGT INTO FRI. THE 00Z CNDN ON THE OTHER
HAND SHOWS A SHARPER UPR RDG AXIS THRU THE PLAINS/MORE PERSISTENT NW
FLOW ALF THRU ONTARIO MAINTAINING A MORE EXPANSIVE SFC HI OVER THE
WRN LKS. THIS CNDN MODEL SCENARIO IS MORE IN LINE WITH THE 00Z GFS
ENSEMBLE MEAN. SO LONGER RANGE FCST WL INCLUDE NO HIER THAN SCHC
POPS FOR THE LATE WEEK PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 126 PM EDT SAT MAY 9 2015
LOW CLOUDS HAVE BEEN SLOW TO BREAK UP SO FAR TODAY...BUT SATELLITE
IMAGERY SHOWS THAT DAYTIME HEATING IS BEGINNING TO MIX OUT SOME OF
THE MOISTURE. AT KIWD...CIGS HAVE ALREADY LIFTED ABOVE 3000FT.
EXPECT VFR CONDITIONS TO PREVAIL THERE THRU THE REMAINDER OF THE
FCST PERIOD. AT KCMX...MVFR CIGS WILL SCATTER OUT TO VFR IN THE NEXT
HR OR SO. VFR CONDITIONS SHOULD THEN CONTINUE THRU THE REMAINDER OF
THE FCST PERIOD. HOWEVER...THERE IS SOME CONCERN THAT AS LOW-LEVEL
WINDS VEER TO A MORE EASTERLY UPSLOPE DIRECTION LATER TONIGHT/SUN
MORNING...MVFR CIGS MAY REDEVELOP. AT KSAW...MVFR CIGS WILL LIKELY
CONTINUE FOR A FEW MORE HRS BEFORE SCATTERING OUT...THOUGH
CONFIDENCE IN THE IMPROVEMENT IS LOW. IF LOW CLOUDS DO NOT SCATTER
OUT BY LATE AFTN...MVFR CIGS WILL LIKELY LINGER THRU THE ENTIRE FCST
PERIOD UNDER AN UPSLOPE WIND. IF THEY DO SCATTER OUT AS CURRENTLY
FCST...MVFR CIGS WILL LIKELY RETURN LATE TONIGHT/SUN MORNING AS
UPSLOPE FLOW TAKES ON A MORE CYCLONIC CURVATURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT MAY 9 2015
NNE WINDS UP TO 20 KTS ON THE SOUTHERN FLANK OF HI PRES IN MANITOBA
WILL INCREASE TONIGHT INTO SUN AS THE PRES GRADIENT TIGHTENS OVER
THE UPPER LAKES AHEAD OF A LO PRES MOVING NE TOWARD THE UPPER MS
RIVER VALLEY FROM THE PLAINS. WHERE THE TERRAIN OVER THE W HALF OF
LAKE SUPERIOR ACCENTUATES THIS FLOW...EXPECT NE GALES TO DEVELOP ON
SUN AFTERNOON AND PERSIST THRU MUCH OF MON AFTERNOON BEFORE THE PRES
GRADIENT WEAKENS SUFFICIENTLY TO ALLOW WINDS TO SUBSIDE UNDER GALE
FORCE. ISSUED A GALE WATCH FOR THE TWO WESTERN LAKE ZONES WHERE THE
GALES ARE MOST LIKELY. WINDS WILL THEN DECREASE STEADILY ON TUE INTO
WED AS THE LO SHIFTS TO THE E AND HI PRES APPROACHES FROM THE
NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
LSZ162.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
733 AM EDT SAT MAY 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SAT MAY 9 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH
EXTENDING FROM HUDSON BAY TO A CLOSED LOW OVER UT/AZ RESULTING IN SW
FLOW FROM THE SRN PLAINS TO THE WRN LAKES. AT THE SFC...HIGH PRES
BUILDING TOWARD THE AREA FROM MANITOBA HAS PUSHED THE COLD FRONT
THROUGH NRN LOWER MI LEAVING NRLY FLOW ACROSS LAKE SUPERIOR AND
UPPER MI. AN AREA OF SHOWERS ASSOCIATED WITH A SHORTWAVE TROUGH
CLOSER TO THE FRONT WAS MOVING FROM NRN LAKE MI INTO FAR NRN LOWER
MI. LOW LEVEL MOISTURE COMBINED WITH UPSLOPE FLOW THAT HAD PRODUCED
SOME PATCHY LIGHT DRIZZLE OVER N CNTRL UPPER MI AROUND 06Z
DISSIPATED AS THE LOWER MOISTURE HAS THINNED WITH CLIMBING/THINNING
CIGS NEAR 4K FT.
TODAY...SOME ADDITIONAL PATCHY DRIZZLE NORTH CENTRAL CANNOT BE RULED
OUT IF MORE LOW LEVEL MOISTURE MOVES IN OFF OF LAKE SUPERIOR. BUT
THIS SEEMS LESS LIKELY GIVEN THE AMOUNT OF SFC-900 MB DRYING
OVERNIGHT. EXPECT CLOUDS TO LINGER DURING THE MORNING AND GIVE WAY TO
SOME CLEARING IN THE AFTERNOON WITH INCREASED MIXING. EXPECT TEMPS TO
REBOUND INTO THE LOW TO MID 60S SOUTH CENTRAL BUT LINGER IN THE UPPER
40S TO AROUND 50 NORTH WITH NRLY WINDS OFF OF LAKE SUPERIOR.
TONIGHT...EXPECT THE CLOUD COVER TO THIN OUT DURING THE AFTERNOON
AND EVENING ENOUGH FOR RADIATIONAL COOLING THAT WILL ALLOW TEMPS TO
DROP INTO THE MID TO UPPER 30S UNTIL INCREASING CLOUDS LATE. THE
MODELS WERE CONSISTENT IN KEEPING ANY PCPN AHEAD OF THE LOW PRES
MOVING THROUGH THE PLAINS SOUTH AND WEST OF THE CWA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 442 AM EDT SAT MAY 9 2015
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE WL FOCUS ON POPS/
QPF/PTYPE EARLY THIS COMING WEEK AS CLOSED LO NOW OVER THE DESERT SW
LIFTS NEWD INTO THE UPR LKS. TEMPS WL RUN BLO NORMAL UNTIL AT LEAST
THE MIDDLE OF NEXT WEEK...WHEN THE LONGER TERM GUIDANCE HINTS AN UPR
RDG WL REBOUND INTO THE UPR MS RIVER VALLEY.
SUN...UPR MI WL BE UNDER THE INFLUENCE OF E FLOW ON THE SRN FLANK OF
HI PRES CENTERED OVER FAR NW ONTARIO. THERE REMAIN DIFFERENCES AMONG
THE MODELS AS TO THE EXTENT OF LLVL MSTR/LO CLDS UNDER THE
SUBSIDENCE INVRN...WITH THE BEST CHC OF MORE EXTENSIVE LO CLD OVER
THE HIER TERRAIN OF THE NCENTRAL AND OVER THE SCNTRL WHERE THE LLVL
FLOW WL UPSLOPE. NO MATTER THE EXTENT OF THE LO CLDS...EXPECT INCRSG
HI/MID CLDS AS THE SW FLOW ALF BECOMES MORE DIFFLUENT AHEAD OF
CLOSED LO LIFTING INTO THE NRN PLAINS. AS FOR POPS...THERE ARE SOME
DIFFERENCES ON THE TRACK OF DISTURBANCE RESPONSIBLE FOR AREA OF
CONVECTION NOW OVER OK. THE 00Z REGIONAL CNDN MODEL AND LOCAL WRF-
ARW SHOW THIS DISTURBANCE MOVING INTO LOWER MI AND FAR ENUF TO THE
NW TO BRING AT LEAST SOME -SHRA TO THE SE CWA MUCH OF THE DAY. OTHER
GUIDANCE...ESPECIALLY RECENT GFS RUNS...SHOW A WEAKER DISTURBANCE
LIFTING NEWD INTO THE UPR LKS WELL IN ADVANCE OF THE MAIN SHRTWV.
BUT SINCE THIS DISTURBANCE TENDS TO OUTRUN THE MORE SGNFT DYNAMIC
FORCING AHEAD OF THE MAIN SHRTWV HANGING BACK WELL TO THE W...WL
FCST NO HIER THAN CHC POPS.
SUN NGT THRU MON NGT...AS CLOSED LO IN THE NRN PLAINS LATE ON SUN
OPENS UP AND DRIFTS INTO THE UPR LKS BY 12Z TUE...ACCOMPANYING SFC
LO IS FCST TO MOVE E FM MN ACRS SCENTRAL UPR MI TO A POINT E OF THE
SAULT BY 12Z TUE. THE TRACK OF THESE FEATURES AND INTERACTION BTWN
ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1
INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS.
OVERALL...THE MODELS TRACK THE SHRTWV/ACCOMPANYING SFC LO FAR ENUF
TO THE N TO SHOW THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETTING UP
TO THE N OF UPR MI. IN THIS SCENARIO...THE WARM CONVEYOR BELT MSTR
RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN
FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST
TO IMPACT MAINLY THE CENTRAL AND ERN CWA FM LATE SUN NGT THRU MON
MRNG...SO FCST WL SHOW THE HIER QPF AND MORE PERSISTENT HIER POPS IN
THAT AREA DURING THAT TIME. BY LATER ON MON...A GOOD NUMBER OF THE
MODELS INDICATE SOME DRY SLOTTING AHEAD OF THE APRCHG SHRTWV WL
IMPACT ALL BUT THE FAR NRN CWA...SO WL LOWER POPS DURING THIS
PERIOD. GIVEN THE TRACK OF THE FEATURES OF INTEREST...MAINTAINED A
SCHC FOR ELEVATED TS N OVER PORTIONS OF THE SCNTRL CWA. ONCE THE
SHRTWV BEGINS TO SHIFT FASTER TO THE E ON MON NGT...AREA OF DEEPER
MSTR/SHARPER DEEP LYR QVECTOR CNVGC TO THE W SHOULD EXPAND INTO THE
CWA AND BRING A RETURN OF MORE NMRS SHOWERS W TO E WITHIN LINGERING
FAIRLY SHARP LLVL CYC FLOW.
TUE...AS THE SHRTWV/SFC LO EXIT TO THE E...DNVA/DEEP LYR QVECTOR
DVGC UNDER RISING HGTS SHOULD CAUSE A LOWERING OF THE POPS DESPITE
LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE
UPSLOPE AREAS OVER THE NRN TIER IMPACTED BY THE N WIND LEFT IN THE
WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR
WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE
SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME
INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM
EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO
NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN
AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA AND END LINGERING PCPN. IF SKIES CLR...
MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF
CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER.
WED THRU FRI...ALTHOUGH UPR RDG/SFC HI PRES ARE FCST TO BLD OVER THE
GRT LKS ON WED FOLLOWING THE EXIT OF THE LO PRES TO THE E...THE 00Z
ECWMF AND ESPECIALLY THE 00Z GFS SHOW A DISTURBANCE RIDING OVER THE
TOP OF THE RDG INITIATING AN AREA OF SHOWERS TO THE NE OF AN H85
WARM FNT DVLPG IN THE UPR MS RIVER VALLEY AND OVERSPREADING AT LEAST
A PORTION OF THE CWA WED NGT INTO FRI. THE 00Z CNDN ON THE OTHER
HAND SHOWS A SHARPER UPR RDG AXIS THRU THE PLAINS/MORE PERSISTENT NW
FLOW ALF THRU ONTARIO MAINTAINING A MORE EXPANSIVE SFC HI OVER THE
WRN LKS. THIS CNDN MODEL SCENARIO IS MORE IN LINE WITH THE 00Z GFS
ENSEMBLE MEAN. SO LONGER RANGE FCST WL INCLUDE NO HIER THAN SCHC
POPS FOR THE LATE WEEK PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 732 AM EDT SAT MAY 9 2015
EXPECT MVFR CIGS THIS MORNING AT ALL TAF SITES TO GIVE WAY TO VFR
CONDITIONS THIS AFTERNOON AS DAYTIME HEATING/MIXING ERODES THE
SHALLOW LAYER OF LOWER CLOUDS. SAW SHOULD SEE A LATER TRANSITION TO
VFR CONDITIONS...BY LATE AFTERNOON...COMPARED TO CMX/IWD WHICH
SHOULD CLEAR OUT EARLIER. THERE IS THE POTENTIAL FOR LOW LEVEL
MOISTURE AND MVFR CONDITIONS TO MOVE IN AGAIN LATE
TONIGHT...ESPECIALLY AT SAW...BUT CONFIDENCE WAS NOT HIGH ENOUGH TO
INCLUDE AT THIS TIME.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT MAY 9 2015
NNE WINDS UP TO 20 KTS ON THE SOUTHERN FLANK OF HI PRES IN MANITOBA
WILL INCREASE TONIGHT INTO SUN AS THE PRES GRADIENT TIGHTENS OVER
THE UPPER LAKES AHEAD OF A LO PRES MOVING NE TOWARD THE UPPER MS
RIVER VALLEY FROM THE PLAINS. WHERE THE TERRAIN OVER THE W HALF OF
LAKE SUPERIOR ACCENTUATES THIS FLOW...EXPECT NE GALES TO DEVELOP ON
SUN AFTERNOON AND PERSIST THRU MUCH OF MON AFTERNOON BEFORE THE PRES
GRADIENT WEAKENS SUFFICIENTLY TO ALLOW WINDS TO SUBSIDE UNDER GALE
FORCE. ISSUED A GALE WATCH FOR THE TWO WESTERN LAKE ZONES WHERE THE
GALES ARE MOST LIKELY. WINDS WILL THEN DECREASE STEADILY ON TUE INTO
WED AS THE LO SHIFTS TO THE E AND HI PRES APPROACHES FROM THE
NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
LSZ162.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
504 AM EDT SAT MAY 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SAT MAY 9 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH
EXTENDING FROM HUDSON BAY TO A CLOSED LOW OVER UT/AZ RESULTING IN SW
FLOW FROM THE SRN PLAINS TO THE WRN LAKES. AT THE SFC...HIGH PRES
BUILDING TOWARD THE AREA FROM MANITOBA HAS PUSHED THE COLD FRONT
THROUGH NRN LOWER MI LEAVING NRLY FLOW ACROSS LAKE SUPERIOR AND
UPPER MI. AN AREA OF SHOWERS ASSOCIATED WITH A SHORTWAVE TROUGH
CLOSER TO THE FRONT WAS MOVING FROM NRN LAKE MI INTO FAR NRN LOWER
MI. LOW LEVEL MOISTURE COMBINED WITH UPSLOPE FLOW THAT HAD PRODUCED
SOME PATCHY LIGHT DRIZZLE OVER N CNTRL UPPER MI AROUND 06Z
DISSIPATED AS THE LOWER MOISTURE HAS THINNED WITH CLIMBING/THINNING
CIGS NEAR 4K FT.
TODAY...SOME ADDITIONAL PATCHY DRIZZLE NORTH CENTRAL CANNOT BE RULED
OUT IF MORE LOW LEVEL MOISTURE MOVES IN OFF OF LAKE SUPERIOR. BUT
THIS SEEMS LESS LIKELY GIVEN THE AMOUNT OF SFC-900 MB DRYING
OVERNIGHT. EXPECT CLOUDS TO LINGER DURING THE MORNING AND GIVE WAY TO
SOME CLEARING IN THE AFTERNOON WITH INCREASED MIXING. EXPECT TEMPS TO
REBOUND INTO THE LOW TO MID 60S SOUTH CENTRAL BUT LINGER IN THE UPPER
40S TO AROUND 50 NORTH WITH NRLY WINDS OFF OF LAKE SUPERIOR.
TONIGHT...EXPECT THE CLOUD COVER TO THIN OUT DURING THE AFTERNOON
AND EVENING ENOUGH FOR RADIATIONAL COOLING THAT WILL ALLOW TEMPS TO
DROP INTO THE MID TO UPPER 30S UNTIL INCREASING CLOUDS LATE. THE
MODELS WERE CONSISTENT IN KEEPING ANY PCPN AHEAD OF THE LOW PRES
MOVING THROUGH THE PLAINS SOUTH AND WEST OF THE CWA.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 442 AM EDT SAT MAY 9 2015
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE WL FOCUS ON POPS/
QPF/PTYPE EARLY THIS COMING WEEK AS CLOSED LO NOW OVER THE DESERT SW
LIFTS NEWD INTO THE UPR LKS. TEMPS WL RUN BLO NORMAL UNTIL AT LEAST
THE MIDDLE OF NEXT WEEK...WHEN THE LONGER TERM GUIDANCE HINTS AN UPR
RDG WL REBOUND INTO THE UPR MS RIVER VALLEY.
SUN...UPR MI WL BE UNDER THE INFLUENCE OF E FLOW ON THE SRN FLANK OF
HI PRES CENTERED OVER FAR NW ONTARIO. THERE REMAIN DIFFERENCES AMONG
THE MODELS AS TO THE EXTENT OF LLVL MSTR/LO CLDS UNDER THE
SUBSIDENCE INVRN...WITH THE BEST CHC OF MORE EXTENSIVE LO CLD OVER
THE HIER TERRAIN OF THE NCENTRAL AND OVER THE SCNTRL WHERE THE LLVL
FLOW WL UPSLOPE. NO MATTER THE EXTENT OF THE LO CLDS...EXPECT INCRSG
HI/MID CLDS AS THE SW FLOW ALF BECOMES MORE DIFFLUENT AHEAD OF
CLOSED LO LIFTING INTO THE NRN PLAINS. AS FOR POPS...THERE ARE SOME
DIFFERENCES ON THE TRACK OF DISTURBANCE RESPONSIBLE FOR AREA OF
CONVECTION NOW OVER OK. THE 00Z REGIONAL CNDN MODEL AND LOCAL WRF-
ARW SHOW THIS DISTURBANCE MOVING INTO LOWER MI AND FAR ENUF TO THE
NW TO BRING AT LEAST SOME -SHRA TO THE SE CWA MUCH OF THE DAY. OTHER
GUIDANCE...ESPECIALLY RECENT GFS RUNS...SHOW A WEAKER DISTURBANCE
LIFTING NEWD INTO THE UPR LKS WELL IN ADVANCE OF THE MAIN SHRTWV.
BUT SINCE THIS DISTURBANCE TENDS TO OUTRUN THE MORE SGNFT DYNAMIC
FORCING AHEAD OF THE MAIN SHRTWV HANGING BACK WELL TO THE W...WL
FCST NO HIER THAN CHC POPS.
SUN NGT THRU MON NGT...AS CLOSED LO IN THE NRN PLAINS LATE ON SUN
OPENS UP AND DRIFTS INTO THE UPR LKS BY 12Z TUE...ACCOMPANYING SFC
LO IS FCST TO MOVE E FM MN ACRS SCENTRAL UPR MI TO A POINT E OF THE
SAULT BY 12Z TUE. THE TRACK OF THESE FEATURES AND INTERACTION BTWN
ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1
INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS.
OVERALL...THE MODELS TRACK THE SHRTWV/ACCOMPANYING SFC LO FAR ENUF
TO THE N TO SHOW THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETTING UP
TO THE N OF UPR MI. IN THIS SCENARIO...THE WARM CONVEYOR BELT MSTR
RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN
FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST
TO IMPACT MAINLY THE CENTRAL AND ERN CWA FM LATE SUN NGT THRU MON
MRNG...SO FCST WL SHOW THE HIER QPF AND MORE PERSISTENT HIER POPS IN
THAT AREA DURING THAT TIME. BY LATER ON MON...A GOOD NUMBER OF THE
MODELS INDICATE SOME DRY SLOTTING AHEAD OF THE APRCHG SHRTWV WL
IMPACT ALL BUT THE FAR NRN CWA...SO WL LOWER POPS DURING THIS
PERIOD. GIVEN THE TRACK OF THE FEATURES OF INTEREST...MAINTAINED A
SCHC FOR ELEVATED TS N OVER PORTIONS OF THE SCNTRL CWA. ONCE THE
SHRTWV BEGINS TO SHIFT FASTER TO THE E ON MON NGT...AREA OF DEEPER
MSTR/SHARPER DEEP LYR QVECTOR CNVGC TO THE W SHOULD EXPAND INTO THE
CWA AND BRING A RETURN OF MORE NMRS SHOWERS W TO E WITHIN LINGERING
FAIRLY SHARP LLVL CYC FLOW.
TUE...AS THE SHRTWV/SFC LO EXIT TO THE E...DNVA/DEEP LYR QVECTOR
DVGC UNDER RISING HGTS SHOULD CAUSE A LOWERING OF THE POPS DESPITE
LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE
UPSLOPE AREAS OVER THE NRN TIER IMPACTED BY THE N WIND LEFT IN THE
WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR
WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE
SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME
INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM
EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO
NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN
AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA AND END LINGERING PCPN. IF SKIES CLR...
MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF
CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER.
WED THRU FRI...ALTHOUGH UPR RDG/SFC HI PRES ARE FCST TO BLD OVER THE
GRT LKS ON WED FOLLOWING THE EXIT OF THE LO PRES TO THE E...THE 00Z
ECWMF AND ESPECIALLY THE 00Z GFS SHOW A DISTURBANCE RIDING OVER THE
TOP OF THE RDG INITIATING AN AREA OF SHOWERS TO THE NE OF AN H85
WARM FNT DVLPG IN THE UPR MS RIVER VALLEY AND OVERSPREADING AT LEAST
A PORTION OF THE CWA WED NGT INTO FRI. THE 00Z CNDN ON THE OTHER
HAND SHOWS A SHARPER UPR RDG AXIS THRU THE PLAINS/MORE PERSISTENT NW
FLOW ALF THRU ONTARIO MAINTAINING A MORE EXPANSIVE SFC HI OVER THE
WRN LKS. THIS CNDN MODEL SCENARIO IS MORE IN LINE WITH THE 00Z GFS
ENSEMBLE MEAN. SO LONGER RANGE FCST WL INCLUDE NO HIER THAN SCHC
POPS FOR THE LATE WEEK PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 132 AM EDT SAT MAY 9 2015
AT KIWD AND KCMX...MVFR CONDITIONS WILL CONTINUE THROUGH SAT MORNING
BEFORE MIXING IN THE AFTERNOON DISSIPATES THE MVFR CIGS.
AT KSAW...IFR UPSLOPE FLOW WILL CONTINUE INTO SAT MORNING BEFORE
HEATING AND MIXING MOVE THE CIG TO MVFR. BY SAT AFTERNOON...ENOUGH
MIXING WILL OCCUR TO DISSIPATE THE MVFR CIG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT MAY 9 2015
NNE WINDS UP TO 20 KTS ON THE SOUTHERN FLANK OF HI PRES IN MANITOBA
WILL INCREASE TONIGHT INTO SUN AS THE PRES GRADIENT TIGHTENS OVER
THE UPPER LAKES AHEAD OF A LO PRES MOVING NE TOWARD THE UPPER MS
RIVER VALLEY FROM THE PLAINS. WHERE THE TERRAIN OVER THE W HALF OF
LAKE SUPERIOR ACCENTUATES THIS FLOW...EXPECT NE GALES TO DEVELOP ON
SUN AFTERNOON AND PERSIST THRU MUCH OF MON AFTERNOON BEFORE THE PRES
GRADIENT WEAKENS SUFFICIENTLY TO ALLOW WINDS TO SUBSIDE UNDER GALE
FORCE. ISSUED A GALE WATCH FOR THE TWO WESTERN LAKE ZONES WHERE THE
GALES ARE MOST LIKELY. WINDS WILL THEN DECREASE STEADILY ON TUE INTO
WED AS THE LO SHIFTS TO THE E AND HI PRES APPROACHES FROM THE
NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
LSZ162.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
443 AM EDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 326 PM EDT FRI MAY 8 2015
A SFC LOW NEAR JAMES BAY IS DRAGGING A SFC TROUGH AND COLD FRONT
ACROSS THE CWA. BEHIND THE LOW IS A 1028MB HIGH OVER THE
SASKATCHEWAN/MANITOBA BORDER. THE COLD FRONT MOVING W TO E ACROSS
THE AREA IS NOW E OF IRON MOUNTAIN. THE NRN PORTION OF THE FRONT
SURGED ACROSS LAKE SUPERIOR AND HAS WRAPPED AROUND THE TERRAIN OF
THE NCENTRAL. THIS MAKES THE FRONT EXTEND FROM E OF IRON MOUNTAIN TO
NEAR WFO MQT TO GWINN AND THEN E TO N OF NEWBERRY. SHOWERS...BUT SO
FAR NO THUNDER...HAVE DEVELOPED AS THE FRONT SURGEST S-SW INTO
NCENTRAL UPPER MI...AGAINS THE LOW LEVEL FLOW. RUC DATA SUGGESTS
500J/KG OF SBCAPE HAS DEVELOPED NEAR IRON MOUNTAIN...BUT LESSER
AMOUNTS CLOSER TO 100J/KG ARE SHOWN WHERE CONVECTION COVERAGE IS
GREATER. CONVECTION MAY BE ABLE TO TAP INTO ENOUGH INSTABILITY FOR
SOME ISOLATED LIGHTNING INTO EARLY THIS EVENING. EXPECT THE PRECIP
TO DIE OUT AS THE FRONT MOVES ONTO LAKE MICHIGAN THIS EVENING AND
SBCAPE DIMINISHES.
LOW LEVEL WINDS BECOME N-NNE TONIGHT AS LOW LEVEL MOISTURE MOVES
OVER THE CENTRAL CWA. THIS WILL ALLOW LOW CLOUDS IN UPSLOPE AREAS OF
NCENTRAL AND ERN UPPER MI THAT WILL ONLY SLIGHTLY DIMINISH THROUGH
THE DAY SAT. CAN NOT RULE OUT SOME SPRINKLES OVER THE NCENTRAL SAT
MORNING...SO LEFT THOSE IN THE FORECAST. SKIES WILL BECOME PARTLY
CLOUDY INLAND WHERE HIGH TEMPERATURES WILL REACH THE UPPER 50S TO
MID 60S. NEAR LAKE SUPERIOR...HIGH TEMPS WILL BE IN THE 40S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 442 AM EDT SAT MAY 9 2015
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE WL FOCUS ON POPS/
QPF/PTYPE EARLY THIS COMING WEEK AS CLOSED LO NOW OVER THE DESERT SW
LIFTS NEWD INTO THE UPR LKS. TEMPS WL RUN BLO NORMAL UNTIL AT LEAST
THE MIDDLE OF NEXT WEEK...WHEN THE LONGER TERM GUIDANCE HINTS AN UPR
RDG WL REBOUND INTO THE UPR MS RIVER VALLEY.
SUN...UPR MI WL BE UNDER THE INFLUENCE OF E FLOW ON THE SRN FLANK OF
HI PRES CENTERED OVER FAR NW ONTARIO. THERE REMAIN DIFFERENCES AMONG
THE MODELS AS TO THE EXTENT OF LLVL MSTR/LO CLDS UNDER THE
SUBSIDENCE INVRN...WITH THE BEST CHC OF MORE EXTENSIVE LO CLD OVER
THE HIER TERRAIN OF THE NCENTRAL AND OVER THE SCNTRL WHERE THE LLVL
FLOW WL UPSLOPE. NO MATTER THE EXTENT OF THE LO CLDS...EXPECT INCRSG
HI/MID CLDS AS THE SW FLOW ALF BECOMES MORE DIFFLUENT AHEAD OF
CLOSED LO LIFTING INTO THE NRN PLAINS. AS FOR POPS...THERE ARE SOME
DIFFERENCES ON THE TRACK OF DISTURBANCE RESPONSIBLE FOR AREA OF
CONVECTION NOW OVER OK. THE 00Z REGIONAL CNDN MODEL AND LOCAL WRF-
ARW SHOW THIS DISTURBANCE MOVING INTO LOWER MI AND FAR ENUF TO THE
NW TO BRING AT LEAST SOME -SHRA TO THE SE CWA MUCH OF THE DAY. OTHER
GUIDANCE...ESPECIALLY RECENT GFS RUNS...SHOW A WEAKER DISTURBANCE
LIFTING NEWD INTO THE UPR LKS WELL IN ADVANCE OF THE MAIN SHRTWV.
BUT SINCE THIS DISTURBANCE TENDS TO OUTRUN THE MORE SGNFT DYNAMIC
FORCING AHEAD OF THE MAIN SHRTWV HANGING BACK WELL TO THE W...WL
FCST NO HIER THAN CHC POPS.
SUN NGT THRU MON NGT...AS CLOSED LO IN THE NRN PLAINS LATE ON SUN
OPENS UP AND DRIFTS INTO THE UPR LKS BY 12Z TUE...ACCOMPANYING SFC
LO IS FCST TO MOVE E FM MN ACRS SCENTRAL UPR MI TO A POINT E OF THE
SAULT BY 12Z TUE. THE TRACK OF THESE FEATURES AND INTERACTION BTWN
ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW AND PWAT AOA 1
INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RA OR SHOWERS.
OVERALL...THE MODELS TRACK THE SHRTWV/ACCOMPANYING SFC LO FAR ENUF
TO THE N TO SHOW THE MAIN COLD CONVEYOR BELT MSTR RIBBON SETTING UP
TO THE N OF UPR MI. IN THIS SCENARIO...THE WARM CONVEYOR BELT MSTR
RIBBON UNDER THE DEEP SSW FLOW AHEAD OF THE SHRTWV WL BE THE MAIN
FORCING MECHANISM FOR THE HIER POPS. THIS AXIS OF HIER MSTR IS FCST
TO IMPACT MAINLY THE CENTRAL AND ERN CWA FM LATE SUN NGT THRU MON
MRNG...SO FCST WL SHOW THE HIER QPF AND MORE PERSISTENT HIER POPS IN
THAT AREA DURING THAT TIME. BY LATER ON MON...A GOOD NUMBER OF THE
MODELS INDICATE SOME DRY SLOTTING AHEAD OF THE APRCHG SHRTWV WL
IMPACT ALL BUT THE FAR NRN CWA...SO WL LOWER POPS DURING THIS
PERIOD. GIVEN THE TRACK OF THE FEATURES OF INTEREST...MAINTAINED A
SCHC FOR ELEVATED TS N OVER PORTIONS OF THE SCNTRL CWA. ONCE THE
SHRTWV BEGINS TO SHIFT FASTER TO THE E ON MON NGT...AREA OF DEEPER
MSTR/SHARPER DEEP LYR QVECTOR CNVGC TO THE W SHOULD EXPAND INTO THE
CWA AND BRING A RETURN OF MORE NMRS SHOWERS W TO E WITHIN LINGERING
FAIRLY SHARP LLVL CYC FLOW.
TUE...AS THE SHRTWV/SFC LO EXIT TO THE E...DNVA/DEEP LYR QVECTOR
DVGC UNDER RISING HGTS SHOULD CAUSE A LOWERING OF THE POPS DESPITE
LINGERING DEEP MSTR. LINGERING SHOWERS WL BE MOST PERSISTENT IN THE
UPSLOPE AREAS OVER THE NRN TIER IMPACTED BY THE N WIND LEFT IN THE
WAKE OF THE DEPARTING SFC LO TO THE E. THE ARRIVAL OF COLDER AIR
WITH H85 TEMPS AS LO AS -5C MAY ALLOW THE PCPN TO MIX WITH SN ON TUE
ESPECIALLY OVER THE HIER TERRAIN OF THE NCNTRL AND W. BUT SINCE
SUFFICIENTLY COLD AIR WL NOT ARRIVE UNTIL AFTER 12Z TUE...DAYTIME
INSOLATION SHOULD LIMIT THE POTENTAIL FOR MUCH IF ANY SN ACCUM
EXCEPT PERHAPS ON GRASSY SFCS. MAX TEMPS WL BE UP TO 20 DEGREES BLO
NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN
AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA AND END LINGERING PCPN. IF SKIES CLR...
MIN TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF
CLOSER TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER.
WED THRU FRI...ALTHOUGH UPR RDG/SFC HI PRES ARE FCST TO BLD OVER THE
GRT LKS ON WED FOLLOWING THE EXIT OF THE LO PRES TO THE E...THE 00Z
ECWMF AND ESPECIALLY THE 00Z GFS SHOW A DISTURBANCE RIDING OVER THE
TOP OF THE RDG INITIATING AN AREA OF SHOWERS TO THE NE OF AN H85
WARM FNT DVLPG IN THE UPR MS RIVER VALLEY AND OVERSPREADING AT LEAST
A PORTION OF THE CWA WED NGT INTO FRI. THE 00Z CNDN ON THE OTHER
HAND SHOWS A SHARPER UPR RDG AXIS THRU THE PLAINS/MORE PERSISTENT NW
FLOW ALF THRU ONTARIO MAINTAINING A MORE EXPANSIVE SFC HI OVER THE
WRN LKS. THIS CNDN MODEL SCENARIO IS MORE IN LINE WITH THE 00Z GFS
ENSEMBLE MEAN. SO LONGER RANGE FCST WL INCLUDE NO HIER THAN SCHC
POPS FOR THE LATE WEEK PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 132 AM EDT SAT MAY 9 2015
AT KIWD AND KCMX...MVFR CONDITIONS WILL CONTINUE THROUGH SAT MORNING
BEFORE MIXING IN THE AFTERNOON DISSIPATES THE MVFR CIGS.
AT KSAW...IFR UPSLOPE FLOW WILL CONTINUE INTO SAT MORNING BEFORE
HEATING AND MIXING MOVE THE CIG TO MVFR. BY SAT AFTERNOON...ENOUGH
MIXING WILL OCCUR TO DISSIPATE THE MVFR CIG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT MAY 9 2015
NNE WINDS UP TO 20 KTS ON THE SOUTHERN FLANK OF HI PRES IN MANITOBA
WILL INCREASE TONIGHT INTO SUN AS THE PRES GRADIENT TIGHTENS OVER
THE UPPER LAKES AHEAD OF A LO PRES MOVING NE TOWARD THE UPPER MS
RIVER VALLEY FROM THE PLAINS. WHERE THE TERRAIN OVER THE W HALF OF
LAKE SUPERIOR ACCENTUATES THIS FLOW...EXPECT NE GALES TO DEVELOP ON
SUN AFTERNOON AND PERSIST THRU MUCH OF MON AFTERNOON BEFORE THE PRES
GRADIENT WEAKENS SUFFICIENTLY TO ALLOW WINDS TO SUBSIDE UNDER GALE
FORCE. ISSUED A GALE WATCH FOR THE TWO WESTERN LAKE ZONES WHERE THE
GALES ARE MOST LIKELY. WINDS WILL THEN DECREASE STEADILY ON TUE INTO
WED AS THE LO SHIFTS TO THE E AND HI PRES APPROACHES FROM THE
NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH MONDAY AFTERNOON FOR
LSZ162.
GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY AFTERNOON FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...KC
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 AM EDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 326 PM EDT FRI MAY 8 2015
A SFC LOW NEAR JAMES BAY IS DRAGGING A SFC TROUGH AND COLD FRONT
ACROSS THE CWA. BEHIND THE LOW IS A 1028MB HIGH OVER THE
SASKATCHEWAN/MANITOBA BORDER. THE COLD FRONT MOVING W TO E ACROSS
THE AREA IS NOW E OF IRON MOUNTAIN. THE NRN PORTION OF THE FRONT
SURGED ACROSS LAKE SUPERIOR AND HAS WRAPPED AROUND THE TERRAIN OF
THE NCENTRAL. THIS MAKES THE FRONT EXTEND FROM E OF IRON MOUNTAIN TO
NEAR WFO MQT TO GWINN AND THEN E TO N OF NEWBERRY. SHOWERS...BUT SO
FAR NO THUNDER...HAVE DEVELOPED AS THE FRONT SURGEST S-SW INTO
NCENTRAL UPPER MI...AGAINS THE LOW LEVEL FLOW. RUC DATA SUGGESTS
500J/KG OF SBCAPE HAS DEVELOPED NEAR IRON MOUNTAIN...BUT LESSER
AMOUNTS CLOSER TO 100J/KG ARE SHOWN WHERE CONVECTION COVERAGE IS
GREATER. CONVECTION MAY BE ABLE TO TAP INTO ENOUGH INSTABILITY FOR
SOME ISOLATED LIGHTNING INTO EARLY THIS EVENING. EXPECT THE PRECIP
TO DIE OUT AS THE FRONT MOVES ONTO LAKE MICHIGAN THIS EVENING AND
SBCAPE DIMINISHES.
LOW LEVEL WINDS BECOME N-NNE TONIGHT AS LOW LEVEL MOISTURE MOVES
OVER THE CENTRAL CWA. THIS WILL ALLOW LOW CLOUDS IN UPSLOPE AREAS OF
NCENTRAL AND ERN UPPER MI THAT WILL ONLY SLIGHTLY DIMINISH THROUGH
THE DAY SAT. CAN NOT RULE OUT SOME SPRINKLES OVER THE NCENTRAL SAT
MORNING...SO LEFT THOSE IN THE FORECAST. SKIES WILL BECOME PARTLY
CLOUDY INLAND WHERE HIGH TEMPERATURES WILL REACH THE UPPER 50S TO
MID 60S. NEAR LAKE SUPERIOR...HIGH TEMPS WILL BE IN THE 40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 435 PM EDT FRI MAY 8 2015
A COOL PERIOD IS SHAPING UP FOR MOST OF THE LONG TERM WITH A DAY OR
TWO OF MUCH BLO NORMAL TEMPS EARLY NEXT WEEK. RIDGE CURRENTLY
BUILDING OVER WRN CANADA WILL FORCE DOWNSTREAM TROFFING INTO ERN
CANADA THRU THE MIDDLE OF NEXT WEEK. BOTH FEATURES WILL THEN BEGIN
TO WEAKEN AFTER MIDWEEK. THIS WILL RESULT IN THE ESTABLISHMENT OF A
LARGE POOL OF COLD AIR JUST TO THE N AND NE OF HERE OVER THE NEXT
SEVERAL DAYS. MEANWHILE...CLOSED MID LEVEL LOW OVER THE SW CONUS IS
EXPECTED TO OPEN UP AS IT LIFTS NE INTO THE GREAT LAKES REGION EARLY
NEXT WEEK. WITH THE ASSOCIATED SFC LOW LIKELY TRACKING BY JUST S OF
UPPER MI...LOW-LEVEL NE WINDS WILL KEEP A SHALLOW TAP FROM THE COLD
AIR TO THE N AND NE....AND THEN AS THE LOW PASSES BY...THE COLD AIR
WILL DUMP INTO THE AREA THRU THE MIDDLE OF NEXT WEEK. THEREAFTER...
RISING HEIGHTS OVER THE WRN LAKES AS THE ERN CANADA TROF LIFTS NE
WILL SPELL A WARMING TREND LATE NEXT WEEK. AS FOR PCPN...THE
AFOREMENTIONED SYSTEM MOVING INTO THE GREAT LAKES REGION EARLY NEXT
WEEK SHOULD BRING A MUCH NEEDED WIDESPREAD RAINFALL TO UPPER MI SUN
THRU TUE...WITH THE SUN NIGHT/MON TIME FRAME LIKELY TO SEE THE BULK
OF THE RAINFALL. WITH THE COLD AIR FOLLOWING THE SYSTEM...SOME AREAS
WILL LIKELY SEE A LITTLE SNOW AS WELL. DRY WEATHER SHOULD THEN BE
THE RULE FOR THE LAST HALF OF THE WORK WEEK.
BEGINNING SAT NIGHT...SFC HIGH PRES WILL BE SETUP ACROSS
MANITOBA/NRN ONTARIO WHILE SFC LOW PRES BEGINS TO LIFT NE OUT OF THE
WRN HIGH PLAINS. UNCERTAINTY IN THE LOW CLOUD FCST ON SAT CARRIES
INTO SAT NIGHT...BUT WOULD THINK THAT AFTER A DAY OF EARLY MAY
DAYTIME HEATING ON SAT...LOW-LEVEL MOISTURE WOULD TEND TO MIX OUT TO
SOME DEGREE. THE NAM WHICH HAS BEEN MUCH MORE PERSISTENT IN HOLDING
LOW-LEVEL MOISTURE OVER THE AREA IS TRENDING DRIER...MORE INLINE
WITH THE GFS...SO THERE MAY NOT BE MUCH STRATOCU TO CONTEND WITH SAT
NIGHT. HIGHER UP...SOME HIGH CLOUDINESS WILL BEGIN TO SPREAD INTO
THE AREA.
ON SUN...MODELS SHOW A WEAK LEAD SHORTWAVE TROF LIFTING INTO THE
UPPER GREAT LAKES WELL IN ADVANCE OF THE MID LEVEL LOW WHICH WILL BE
MOVING TO NEBRASKA/SD. GOOD SURGE OF 700MB MOISTURE TRANSPORT AND
DECENT ISENTROPIC ASCENT SHOULD SUPPORT AT LEAST SCT SHRA SPREADING
NE INTO THE FCST AREA DURING THE DAY. BEST CHC WILL BE OVER THE W
WHERE MORE SUSTAINED FORCING IS INDICATED.
SUN NIGHT THRU MON NIGHT...MID LEVEL LOW OVER NEBRASKA/SD SUN
EVENING WILL OPEN UP AND MOVE TO THE WRN GREAT LAKES. ASSSOCIATED
SFC LOW SHOULD MOVE ACROSS SRN MN INTO NRN WI AND THEN TO VCNTY OF
THE STRAITS. THERE HAS BEEN A TREND FROM MANY OF THE MODELS FOR A
SLIGHTLY FARTHER N TRACK SO THAT THE SFC LOW PASSES ACROSS SRN AND
ERN UPPER MI LATE MON AFTN/MON EVENING. THE TRACK OF THESE FEATURES
AND ACCOMPANYING DYNAMIC FORCING/DIFFLUENT UPPER FLOW/PRECIPITABLE
WATER AOA 1 INCH INDICATE THERE WILL BE AT LEAST PERIODS OF RAIN. IF
THE TREND FOR A FARTHER N LOW TRACK IS VALID...BREAKS IN THE PCPN
WOULD BE MORE LIKELY...ESPECIALLY ACROSS THE S. ON THE OTHER
HAND...IF THE LOW TRACK IS FARTHER S...MORE PERSISTENT PCPN WILL
OCCUR. AT THIS POINT...LOOKS LIKE WIDESPREAD PCPN AMOUNTS IN THE 0.5
TO 1 INCH RANGE ARE LIKELY SUN NIGHT/MON. MAINTAINED A MENTION OF
SCHC THUNDER OVER THE SCNTRL SUN NGT INTO MON INLIGHT OF THE
POTENTIAL FARTHER N LOW TRACK AND ELEVATED INSTABILITY THAT PUSHES
INTO THE AREA ON THE MODELS WITH THE FARTHER N TRACK. AS THE LOW
TRACKS TO AROUND THE STRAITS MON NIGHT...THE STEADIER/HEAVIER PCPN
WILL EXIT TO THE E. HOWEVER...MORE PERSISTENT LIGHT PCPN WILL
LINGER...MAINLY ACROSS THE N. AS COLDER AIR BEGINS TO SPREAD S
BEHIND THE LOW (850MB TEMPS AS LOW AS AROUND -2C LATE MON NIGHT)...
SNOW MAY BEGIN TO MIX WITH THE RAIN OVER THE HIGH TERRAIN OF THE W.
WITH 850MB TEMPS FALLING TO -3C TO AS LOW AS -6C TUE...LINGERING
LIGHT RAIN WILL BE MORE LIKELY TO MIX WITH SNOW...ESPECIALLY OVER
THE HIGH TERRAIN OF THE W AND NCNTRL BEFORE THE ARRIVAL OF MORE
ANTICYCLONIC FLOW/DRIER AIR CAUSES THE PCPN TO DIMINISH LATER IN THE
DAY. DAYTIME INSOLATION WILL CERAINLY LIMIT THE POTENTAIL FOR MUCH
IF ANY SNOW ACCUMULATION...EXCEPT PERHAPS ON GRASSY SFCS.
DRY/COOL WEATHER WILL FOLLOW FOR WED AS SFC HIGH PRES BUILDS INTO
THE UPPER LAKES.
THU/FRI...RELIED MORE ON THE ENSEMBLES DUE TO RATHER SIGNIFICANT
UNCERTAINTY IN THE LATE WEEK FLOW PATTERN OVER N AMERICA. WHILE THE
GFS MAINTAINS MORE TROFFING IN ERN CANADA (SLOWER RELAXING OF NW
FLOW FOR THE UPPER LAKES)...THE ECMWF SHOWS QUICKER DEPARTURE OF THE
TROF WHICH ALLOWS FOR ANOTHER DISTURBANCE TO MOVE OUT OF THE ROCKIES
AND REACH THE GREAT LAKES THU NIGHT. THE ENSEMBLE APPROACH RESULTS
IN RIDGING DEVELOPING OVER THE MISSISSIPPI VALLEY AND CONNECTING UP
WITH THE WEAKENING WRN CANADA RIDGE. IN TURN...THIS CAUSES MORE
PERSISTENT SFC HIGH PRES LINGERING OVER THE GREAT LAKES REGION...AND
THUS DRY WEATHER LIKELY PREVAILING FOR THE LAST HALF OF THE WORK
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 132 AM EDT SAT MAY 9 2015
AT KIWD AND KCMX...MVFR CONDITIONS WILL CONTINUE THROUGH SAT MORNING
BEFORE MIXING IN THE AFTERNOON DISSIPATES THE MVFR CIGS.
AT KSAW...IFR UPSLOPE FLOW WILL CONTINUE INTO SAT MORNING BEFORE
HEATING AND MIXING MOVE THE CIG TO MVFR. BY SAT AFTERNOON...ENOUGH
MIXING WILL OCCUR TO DISSIPATE THE MVFR CIG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT FRI MAY 8 2015
SW-NW WINDS BEHIND A COLD FRONT THAT MOVED THROUGH TODAY WILL
DIMINISH SOME THIS EVENING INTO TONIGHT AND REMAIN BELOW 20KTS
THROUGH SAT NIGHT. AS LOW PRESSURE SLIDES FROM THE CENTRAL PLAINS TO
THE UPPER LAKES FROM SUNDAY INTO MONDAY...NORTH TO NORTHEAST WINDS
OF 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP...ESPECIALLY OVER THE
WEST. GALE FORCE GUSTS TO 35 KNOTS ARE EXPECTED OVER WESTERN
LAKE SUPERIOR SUNDAY NIGHT INTO MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...07
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS DULUTH MN
421 AM CDT SAT MAY 9 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 421 AM CDT SAT MAY 9 2015
CLOUDY AND SEASONABLE OVER THE WEEKEND WITH RAIN BEGINNING LATE
SATURDAY AND INTO SUNDAY. HIGH PRESSURE OVER CENTRAL MANITOBA WILL
MOVE EAST INTO NORTHWEST ONTARIO TODAY AS A LOW PRESSURE SYSTEM
MOVES NORTH ACROSS THE CENTRAL PLAINS TODAY INTO TOMORROW. WITH A
HIGH TO THE NORTH AND AN INCOMING LOW PRESSURE SYSTEM TO THE SOUTH
LOW LEVEL FLOW WILL BE GENERALLY EASTERLY ACROSS LAKE SUPERIOR
THROUGH THE SHORT TERM...WHICH WILL LEAD TO COOLER TEMPERATURES BY
THE LAKE.
TODAY...STRATUS HAS DEVELOPED ACROSS PARTS OF NORTHERN MINNESOTA AND
WILL PERSIST THROUGH LATE MORNING WHEN DIURNAL HEATING SHOULD ALLOW
MIXING TO TAKE PLACE AT LOW LEVELS AND CAUSE STRATUS TO BEGIN TO
DISSIPATE. HOWEVER...MID LEVEL CLOUDS WILL MOVE IN DURING THE LATE
AFTERNOON...SO WINDOW FOR PARTLY SUNNY SKIES TODAY WILL BE FAIRLY
BRIEF. WITH LOW LEVELS SATURATED THROUGH THE LATE MORNING INTO THE
EARLY AFTERNOON IT WILL NOT TAKE MUCH LARGE-SCALE LIFT TO CAUSE SOME
DRIZZLE/SPRINKLES...AND THERE IS A CHANCE A MID-LEVEL IMPULSE MOVING
ACROSS COULD LEAD TO SOME LIGHT RAIN...BUT THESE CHANCES ARE VERY
LOW. HAVE CHOSEN NOT TO INCLUDE ANY PRECIP IN THE FORECAST THIS
MORNING DUE TO DEW POINT DEPRESSIONS AT AROUND 5F OR GREATER AND
EXPECTED TO REMAIN THIS WAY THROUGH THE AFTERNOON. NEAR THE LAKE
EASTERLY WINDS WILL BE LIGHT BUT STILL PERSISTENT ENOUGH TO RESULT
IN HIGHS ONLY IN THE 40S...ELSEWHERE TEMPERATURES SHOULD WARM TO THE
MID TO UPPER 50S IN NORTHEAST MINNESOTA AND INTO THE LOW 60S IN
NORTHWEST WISCONSIN WHERE THERE IS A BETTER CHANCE FOR SUNNY SKIES
TO BREAK OUT IN THE AFTERNOON.
TONIGHT...INCREASING MID-LEVEL MOISTURE AND STRONG WARM AIR
ADVECTION WILL LEAD TO LIGHT PRECIP DEVELOPING IN CENTRAL AND
NORTHERN MINNESOTA LATE TONIGHT AND INTO NORTHWEST WISCONSIN BY
EARLY SUNDAY MORNING. GUIDANCE IN GENERAL AGREEMENT THAT A BAND OF
LIGHT RAIN WILL DEVELOP IN NORTH-CENTRAL MINNESOTA ASSOCIATED WITH
THE ENTRANCE REGION OF AN UPPER LEVEL JET AND ALONG A THETA-E RIDGE.
IN GENERAL REALLY DO NOT EXPECT MUCH MEASURABLE PRECIP
OVERNIGHT...JUST INCREASING CLOUDS IN MOST LOCATIONS. OVERNIGHT LOWS
IN THE UPPER 30S TO MID 40S.
SUNDAY...CLOUDY...WINDY...AND RAIN. SFC LOW MOVES NORTH FROM
WESTERN-CENTRAL NEBRASKA INTO EASTERN SOUTH DAKOTA LEADING TO
WIDESPREAD RAINFALL ACROSS THE ENTIRE REGION. PRECIPITATION SHOULD
BEGIN IN MOST LOCATIONS BY NOON OR SO. IN GENERAL INTENSITY SHOULD
BE LIGHT WITH BROAD LARGE-SCALE FORCING IN PLACE...AND THERMODYNAMIC
PROFILES INDICATE A GENERALLY STABLE ENVIRONMENT...SO DO NOT EXPECT
THUNDER THROUGH THE LATE AFTERNOON. HIGHER RES GUIDANCE A BIT MORE
PESSIMISTIC ON PRECIP COVERAGE COMPARED TO LARGER-SCALE
PARAMETERIZED GUIDANCE...AND GIVEN PAST FEW PRECIP EVENTS WOULD TEND
TO SIDE TOWARDS THE SCATTERED SHOWERS SCENARIO OF THE HIGH RES
GUIDANCE. NORTHEASTERLY WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS UP ACROSS THE REGION...WITH A CORRIDOR OF THE STRONGEST
WINDS FROM THE TWIN PORTS WEST TO THE BRAINERD LAKES REGION OF 15 TO
25 MPH WITH GUSTS TO AROUND 35 MPH AT TIMES...PERHAPS A FEW GUSTS
APPROACHING 45 MPH. TEMPERATURES COOLER...IN THE LOW TO MID 40S BY
LAKE SUPERIOR WITH LOW 50S ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 421 AM CDT SAT MAY 9 2015
STRONG LOW PRESSURE SYSTEM MOVING UP FROM EASTERN NEBRASKA SUNDAY
EVENING EAST ACROSS MINNESOTA TO NORTHERN WISCONSIN THROUGH MONDAY.
STRONG WARM AIR ADVECTION UP OVER THE WARM FRONT ALONG WITH
FRONTOGENESIS WILL CONTINUE TO SPREAD RAIN INTO THE AREA ON SUNDAY
EVENING...AND CONTINUING ON MONDAY. THE LOW CENTER PASSES EAST OF
THE AREA MONDAY AFTERNOON AND EVENING...AND THE SYSTEM BEGINS TO
WRAP COLDER AIR INTO THE AREA FOR MONDAY NIGHT AND EARLY TUESDAY
BEFORE THE SYSTEM MOVES OFF TO THE EAST. THIS COLDER AIR ALOFT IS
LIKELY TO HELP TURN THE RAINFALL OVER TO A MIXTURE OF RAIN AND
SNOW...MAINLY MONDAY NIGHT AND EARLY TUESDAY. DO NOT EXPECT ANY
ACCUMULATIONS AS TEMPERATURES ARE TOO WARM FOR MORE THAN FLAKES IN
THE AIR AND SHOULD MELT ONCE THEY HIT THE GROUND. TEMPERATURES TO
ONLY RISE INTO THE 40S FOR MOST OF THE AREA ON MONDAY...WITH SOME
50S ACROSS THE SOUTHEAST.
QUIET CONDITIONS RETURN FOR TUESDAY NIGHT AND WEDNESDAY AS A RIDGE
OF HIGH PRESSURE SLIDES ACROSS THE AREA. HOWEVER...ANOTHER STRONG
SPRING STORM SYSTEM IS EXPECTED TO MOVE ACROSS THE MIDWEST WEDNESDAY
THROUGH FRIDAY...WITH MAINLY RAIN EXPECTED THROUGH THE PERIOD.
TEMPERATURES TO START OUT AS FAIRLY COOL WITH HIGHS NEAR TO BELOW
NORMAL WEDNESDAY...GRADUALLY WARMING TO ABOVE NORMAL BY FRIDAY AS
THE SYSTEM ADVECTS MORE WARM AIR INTO THE AREA THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z FATS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 100 AM CDT SAT MAY 9 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS...EXCEPT FOR KINL AND
KDLH THROUGH THE FORECAST PERIOD. LATEST NAM/DLHWRF SOUNDINGS HAVE A
GOOD HANDLE ON THE CURRENT CONDITIONS. SO EXPECT KINL TO REMAIN IN
MVFR CIGS UNTIL AROUND 18Z. LAST SEVERAL HRRR RUNS...ALONG WITH
THE LATEST NAM/DLHWRF SOUNDINGS SHOW MVFR CIGS MOVE INTO KDLH
AROUND 11Z UNTIL 19Z. HRRR SHOWS A POSSIBILITY OF IFR CIGS FOR A
FEW HOURS...BUT NOT CONFIDENT ENOUGH TO ADD. AFTER 19Z ALL TAF
SITES EXPECTED TO BE VFR. WINDS GENERALLY LIGHT THROUGHOUT THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 54 38 44 37 / 10 30 60 100
INL 57 35 53 37 / 10 10 50 80
BRD 62 43 51 40 / 0 80 90 90
HYR 64 41 58 44 / 0 40 60 90
ASX 54 36 46 39 / 10 20 60 90
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...LE
AVIATION...LE/WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
101 AM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 946 PM CDT FRI MAY 8 2015
FORECAST IS ON TRACK. ONLY MINOR UPDATE TO CLOUD COVER AND CLEAN
UP THE EARLY EVENING WORDING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 321 PM CDT FRI MAY 8 2015
CLEARING HAS BEEN SLOW THIS AFTERNOON...BUT HAS BEEN INCREASING
OVER THE PAST HOUR. CLEARING WAS MOST PRONOUNCED FROM THE
BRAINERD LAKES REGION EAST NORTHEAST TO THE TWIN PORTS. 20Z
SATELLITE IMAGERY ALSO SHOWED CLEARING DEVELOPING OVER PARTS OF
THE ARROWHEAD WITH MORE HOLES OPENING OVER PORTIONS OF NORTHWEST
WISCONSIN. THE RAP HAS DONE A DECENT JOB WITH THIS...AS EARLY RUNS
SHOWED AN ACCELERATION IN THE CLEARING BY LATE AFTERNOON. THERE
ARE QUESTIONS ON HOW MUCH ADDITIONAL CLEARING WILL OCCUR TONIGHT.
THE RAP AND NAM SUGGEST CLOUDS MAY NOT CLEAR OVER PARTS OF FAR
NORTHERN MINNESOTA OR WILL MOVE BACK IN OVERNIGHT AS THE FLOW
VEERS TO NORTHEAST. WE DID INCREASE CLOUD COVER OVER
NORTHERN/NORTHEAST MINNESOTA TONIGHT...BUT DID NOT GO AS HIGH AS
THE RAP WOULD SUGGEST AT THIS TIME. THE AMOUNT OF CLOUD COVER WILL
HAVE A BIG IMPACT ON TEMPERATURES TONIGHT...AND THEY MAY HAVE TO
BE ADJUSTED THROUGH THE EVENING AS CLOUD TRENDS BECOME CLEARER.
IF THE LOWER CLOUDS DO DEVELOP TONIGHT...THEY ARE EXPECTED TO THIN
THROUGH THE DAY BUT SOME CUMULUS DEVELOPMENT IS THEN EXPECTED.
MORE CLOUDS WILL DEVELOP DUE TO A SHORTWAVE AND AREA OF FGEN
FORCING...MAINLY OVER FAR NORTHERN MINNESOTA DURING THE AFTERNOON. AT THIS
TIME...IT DOES NOT APPEAR THE FORCING WILL BE STRONG ENOUGH FOR
PRECIP TO DEVELOP. HIGHS ARE EXPECTED TO RANGE FROM THE UPPER
FIFTIES TO MIDDLE SIXTIES...WARMEST FAR SOUTH. IT WILL BE COOLER
AROUND LAKE SUPERIOR WITH AN ONSHORE FLOW.
A LARGE AREA OF LOW PRESSURE WILL APPROACH FROM THE SOUTH SATURDAY
NIGHT. MOST AREAS WILL REMAIN DRY...BUT FAR SOUTHERN AREAS MAY SEE
SOME RAIN LATE. WINDS WILL BE INCREASING THROUGH THE NIGHT AROUND
LAKE SUPERIOR DUE TO INCREASING PRESSURE FALLS AHEAD OF THE LOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 321 PM CDT FRI MAY 8 2015
STRONG WARM ADVECTION AHEAD OF A DEEP LOW PRESSURE AREA WILL CREATE
A STRONG AND ACTIVE BAROCLINIC ZONE OVER MUCH OF THE FORECAST AREA
BEGINNING SATURDAY NIGHT AND CONTINUING INTO MONDAY. THIS RAIN
GO-ROUND IS SOMEWHAT SIMILAR TO OUR PAST RAIN...WITH THE STRONG WARM
AIR ADVECTION AND LOW LEVEL JET CAUSING WIDESPREAD RAIN TO SPREAD
NORTH. AS THE SFC LOW PASSES EAST...A COLD FRONT WILL MOVE THROUGH
MONDAY AFTERNOON AND EVENING. THE DIFFERENCE IS THAT THIS LOW COMING
UP IS MUCH STRONGER. AS A RESULT THE EAST WINDS THAT WILL ROTATE
AROUND THE LOW WILL BE MUCH STRONGER. WITH THE LOW FORECAST TO BE
SOMEWHERE OVER OR NEARING SOUTHERN MN SUNDAY AFTERNOON...THERE WILL
BE STRONG EAST WINDS ACROSS THE FORECAST AREA. WITH FORECAST 925-850
MB WINDS UP TO 50 KT...LOOKS LIKE A BLUSTERY AND WAVY DAY ON LAKE
SUPERIOR. THE LOW`S MOVEMENT INTO NRN WI ON MONDAY WILL PROLONG THE
STRONG EAST WINDS OVER LAKE SUPERIOR...UNTIL TUESDAY MORNING WITH
THE LOW WELL EAST OF THE AREA.
THE UPPER LEVEL FLOW IS SPLIT WITH THE NORTHERN BRANCH NOT AFFECTING
US UNTIL LATER. ITS THE SOUTHERN BRANCH THAT WILL BRING THE DEEP TROF
ACROSS THE MIDWEST THROUGH TUESDAY. THE MODELS ARE IN GENERAL
AGREEMENT WITH THE SCENARIO...ALTHOUGH THE GFS IS MUCH MORE BULLISH
ON SUBSEQUENT PRECIPITATION AS THE NAM AND ECMWF BRING IN A DRY SLOT
TO CUT DOWN ON PRECIP AMOUNTS.
BY MONDAY NIGHT THERE WILL BE SOME COLD ENOUGH AIR TO HAVE SNOW.
WITH THE COLD AIR ADVECTION BEHIND THE LOW...WE WILL SEE COLUMN TEMPS
TO PLUMMET WELL BELOW FREEZING AND BELOW THE ICE CRYSTAL TEMPS.
ANOTHER LOW WILL APPROACH WEDNESDAY AFTERNOON AND BRING ANOTHER
CHANCE OF SHOWERS THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z FATS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 100 AM CDT SAT MAY 9 2015
VFR CONDITIONS EXPECTED AT ALL TERMINALS...EXCEPT FOR KINL AND
KDLH THROUGH THE FORECAST PERIOD. LATEST NAM/DLHWRF SOUNDINGS HAVE A
GOOD HANDLE ON THE CURRENT CONDITIONS. SO EXPECT KINL TO REMAIN IN
MVFR CIGS UNTIL AROUND 18Z. LAST SEVERAL HRRR RUNS...ALONG WITH
THE LATEST NAM/DLHWRF SOUNDINGS SHOW MVFR CIGS MOVE INTO KDLH
AROUND 11Z UNTIL 19Z. HRRR SHOWS A POSSIBILITY OF IFR CIGS FOR A
FEW HOURS...BUT NOT CONFIDENT ENOUGH TO ADD. AFTER 19Z ALL TAF
SITES EXPECTED TO BE VFR. WINDS GENERALLY LIGHT THROUGHOUT THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 39 42 37 41 / 10 70 80 80
INL 37 52 36 45 / 10 40 50 60
BRD 43 48 39 48 / 20 80 80 70
HYR 41 54 41 50 / 10 70 80 70
ASX 36 48 37 45 / 10 60 80 80
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...LE/WL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
952 PM CDT SUN MAY 10 2015
.UPDATE...
MINOR ADJUSTMENTS TO TEMPS AND POPS OVERNIGHT.
&&
.SHORT TERM...
RADAR SHOWS THAT EARLIER CONVECTION OVER NE LA HAS WEAKENED TO JUST
SOME REMNANT LIGHT SHRA AND SPRINKLES. SKIES ARE PARTLY CLOUDY OVER
AREA WITH CIRRUS OUTFLOW FROM UPSTREAM CONVECTION THE PRIMARY CLOUD
COVER. PRIMARY FORECAST PROBLEM FOR TONIGHT IS CENTERED AROUND HOW
FAR EAST ORGANIZED CONVECTION CURRENTLY FROM NE TX INTO WRN AR WILL
PROGRESS TOWARD OUR AREA OVERNIGHT. HIGH RES MODELS...INCLUDING
LATEST RUNS OF HRRR...HAVE BEEN FAIRLY INSISTENT ON MOVING CONVECTION
EAST INTO NE LA AND SE AR AROUND 12Z. CONVERSELY GLOBAL MODELS AND
MOST RECENT NAM ARE SLOWER TO BRING ACTIVITY EAST. ACTIVITY IS NOT
PROGRESSING VERY RAPIDLY EAST AND FOR NOW HAVE JUST PRETTY MUCH LEFT
GOING FORECAST AS IS WITH REGARD TO POPS SHOWING CHANCE TO SLIGHT
CHANCE POPS IN FAR WESTERN AREAS LATE TONIGHT. DID BRING SLIGHT
CHANCE POPS A LITTLE FARTHER SE INTO E CENTRAL LA TO ACCOUNT FOR
POSSIBILITY A FEW ISOLATED SHRA/TSRA COULD BUILD DOWN INTO AREA AS
MID LEVEL HEIGHT FALLS SKIRT AREA LATE TONIGHT. OTHER FORECAST
CONCERN IS POTENTIAL FOR ANY DENSE FOG...RIGHT NOW THINK THAT
INCREASING LOW LEVEL FLOW WILL RESULT IN PRIMARILY STRATUS RATHER
THAN SIGNIFICANT AREAS OF DENSE FOG SO HAVE LEFT ANY MENTION OUT OF
GRIDS OR HWO. THIS IS SUPPORTED BY HRRR WHICH KEEPS VSBY ISSUES VERY
LOCALIZED.
ONGOING FORECAST OF LIMITED SEVERE POTENTIAL FOR MON STILL APPEARS
REASONABLE BASED ON LATEST GUIDANCE. LATEST NAM CONTINUES TREND OF
INCREASING 500 MB FLOW TO 40-45 KT ACROSS N/W AREAS AS STRONGER MID
LEVEL TROUGH PASSES BY TO OUR N. MODERATELY STRONG LAPSE RATES AND
HIGH LOW LEVEL MOISTURE WOULD SUPPORT AT LEAST A LIMITED SEVERE RISK
SHOULD ORGANIZED CONVECTION RESULT. ALL OF THIS WILL REVOLVE AROUND
TIMING/LOCATION OF CONVECTIVE EVOLUTION. RISK OF STRONG/SEVERE
CONVECTION WOULD BE MAXIMIZED IF CONVECTIVE ACTIVITY IS SLOWER AND
MORE TIED TO NEXT WAVE OF HEIGHT FALLS WHICH MOVE OVER AREA MON
AFTERNOON. IF MORE WIDESPREAD CONVECTION MOVES EAST MORE QUICKLY IN
THE MORNING AND PUSHES CONVECTIVE OUTFLOW WELL SE INTO AREA FAIRLY
EARLY...THIS WOULD LIKELY REDUCE THE RISK OF STRONG/SEVERE STORMS.
/AEG/
&&
.AVIATION...
AS HAS OCCURRED LAST FEW NIGHTS...EXPECT IFR/LIFR CONDITIONS TO
DEVELOP IN FAR SE AS GULF MOISTURE ADECTS INTO AREA AHEAD OF SYSTEM
TO THE WEST. STRONGER LOW LEVEL WINDS MAY ALLOW AT LEAST MVFR
CONDITIONS TO PENETRATE AS FAR N AS I-20. EXPECT THESE CONDITIONS TO
IMPROVE BY 15Z WITH MORNING MIXING. FOR NOW LIMITED VCTS MENTION TO
KGWO/KGLH BASED ON UNCERTAINTY OF CONVECTIVE EVOLUTION...LATER
FORECASTS WILL REFINE THE CONVECTIVE POTENTIAL BASED ON LATER TRENDS
IN OBSERVATIONAL DATA AND HIGH RES MODELS. /AEG/
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT SUN MAY 10 2015/
SHORT TERM...TONIGHT THROUGH MONDAY...MID LEVEL RIDGING WILL BEGIN
TO SHIFT FURTHER EAST TONIGHT AS MID LEVEL TROUGHING DEEPENS OVER
THE EASTERN PLAINS. EXPECT MOST OF TONIGHT TO REMAIN RAIN FREE...BUT
AS A COLD FRONT APPROACHES THE NORTHWEST PORTIONS OF THE AREA THERE
WILL BE INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS IN THE DELTA
BY MONDAY MORNING. THE BOUNDARY WILL MOVE INTO THE DELTA MONDAY
AFTERNOON AND SLOWLY DRIFT FURTHER SOUTH ACROSS THE AREA INTO THE
AFTERNOON HOURS. THE GLOBAL MODELS INDICATE THAT THERE WILL BE
DECENT DEEP LAYER SHEAR AROUND 30-35KTS IN THE DELTA MONDAY MORNING
INTO THE EARLY AFTERNOON HOURS ALONG WITH PLENTY OF MOISTURE AND
H700-H500 LAPSE RATES OF ABOUT 6.5-6.8 CM/KM. THIS PERIOD LOOKS LIKE
THE BEST OPPORTUNITY FOR SEVERE STORMS ACROSS THE AREA.
THE MODELS SUGGEST THAT THE BOUNDARY WILL HAVE LITTLE UPPER SUPPORT
AS IT MOVES FURTHER SOUTH INTO THE AREA AS THE BEST FORCING LIFTS
NORTHEAST OF THE AREA. AS WE GET INTO THE AFTERNOON AND EVENING
HOURS WHATS LEFT OF THE BOUNDARY WILL EXTEND GENERALLY ALONG THE
NATCHEZ TRACE CORRIDOR. THE LOW LEVEL FLOW AND DEEP LAYER SHEAR WILL
BE RELATIVELY WEAK BY MID/LATE AFTERNOON ACROSS THE AREA...BUT WITH
AFTERNOON HEATING...H700-H500 LAPSE RATES OF ABOUT 6.5-7.0 CM/KM
.ML CAPES OF 1400-1700 J/KG...STRONG TO POSSIBLY SEVERE STORMS
WILL BE POSSIBLE ACROSS MUCH OF THE AREA MONDAY AFTERNOON/EVENING.
AS WE GET INTO MONDAY NIGHT BOTH THE GFS/ECMWF DISSIPATE MUCH OF THE
CONVECTION DURING THE EVENING INTO THE OVERNIGHT HOURS...BUT
REDEVELOP STORMS ALONG THE BOUNDARY VERY EARLY TUESDAY MORNING AS
ANOTHER SHORT WAVE MOVES ACROSS THE AREA. WITH LIMITED
INSTABILITY/SHEAR EXPECT THESE STORMS TO REMAIN BELOW SEVERE LIMITS.
THIS SHORT WAVE WILL PUSH THE BOUNDARY A LITTLE FURTHER SOUTH
THROUGH THE DAY ON TUESDAY AND WILL EXTEND OVER THE SOUTHERN
PORTIONS OF THE AREA BY LATE TUESDAY AFTERNOON. HIGH PRESSURE
RIDGING AND DRIER AIR WILL BUILD IN BEHIND THE FRONT ACROSS MUCH OF
THE AREA ON TUESDAY WITH ONLY ISOLATED THUNDERSTORM CHANCES IN THE
SOUTH BY LATE AFTERNOON/EARLY EVNING. EXPECT ALL OF THE THUNDERSTORM
ACTIVITY TO END BY SUNSET. HIGH PRESSURE AND SLIGHTLY DRIER/COOLER
AIR WILL BUILD IN TUESDAY NIGHT WITH LOWS FALLING INTO THE UPPER 50S
TO LOW 60S ACROSS MUCH OF THE AREA./15/
LONG TERM...WEDNESDAY THROUGH SUNDAY...FOR WED INTO THU...LESS
PRECIP POTENTIAL LOOKS TO EXIST WITH AN OVERALL QUIETER PERIOD AS
THE WEAK FRONT IS JUST TO OUR SOUTH AND STALLS. HOWEVER...I WILL ADD
THAT THIS IS A LOWER CONFIDENCE FORECAST PERIOD AS GLOBAL GUID
SOLUTIONS VARY AS SOME BRING THE FRONT BACK NORTHWARD A BIT SOONER.
WHILE MOST ARE DRY THE CANADIAN IS WETTER AND BRINGS PRECIP BACK
MORE QUICKLY. BLENDED GUIDANCE POPS WERE USED WITH THE BETTER RAIN
CHANCES ACROSS THE WEST.
WHILE THERE WILL BE UPPER LEVEL RIDGING CLOSE...THE AREA DOES LOOK
TO BE CLOSE ENOUGH TO SOME SHORT WAVE TO INCREASE PRECIP POTENTIAL
AROUND FRIDAY WHICH COULD ALSO LINGER INTO SATURDAY. HOWEVER...
STRONGER RIDGING LOOKS TO BUILD BY LATER ON SATURDAY AND ESPECIALLY
INTO SUNDAY. IF THIS TREND DOES PAN OUT...I EXPECT PRECIP CHANCES TO
TREND LOWER(LESS) WITH TEMPS EVEN WARMER.
AS FOR TEMPS THIS WEEK AND INTO THE WEEKEND. TUE-WED LOOK TO BE
INFLUENCE MOST BY THE SFC COOL FRONT WITH MUCH OF THE CWA SEEING
HIGHS RANGING FROM THE UPPER 70S TO LOWER 80S. THE WARMEST AREAS
WILL BE OVER THE SE WHERE MID 80S ARE EXPECTED. LOOK FOR A GRADUAL
BUT STEADY WARMING TREND FOR LATE WEEK AND INTO THE WEEKEND. MORE
MID/UPPER 80S WILL BEGIN TO SHOW UP WITH A PUSH FOR 90 VERY POSSIBLE
IF THE UPPER RIDGE BUILDS AND CLOUDS ARE LESS. LOWS WILL BE A TAD
COOLER AND CLOSER TO CLIMO FOR WED-THU MORNINGS...BUT A WARMER AND
MORE HUMID TREND SHOULD BE EXPECTED FOR LATE WEEK AND INTO THE
WEEKEND. /CME/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 68 86 67 81 / 8 40 61 62
MERIDIAN 65 87 66 81 / 4 20 49 58
VICKSBURG 70 85 67 80 / 16 58 60 62
HATTIESBURG 67 89 68 85 / 4 21 27 65
NATCHEZ 71 86 66 81 / 16 51 54 66
GREENVILLE 71 83 64 77 / 34 72 40 46
GREENWOOD 69 84 64 79 / 12 58 42 45
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AEG/JAN/
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1016 PM CDT Sun May 10 2015
.UPDATE:
Issued at 1006 PM CDT Sun May 10 2015
While there has been a lull in shower and thunderstorms across the
area over the last few hours, the probability is expected to ramp
back up overnight. A series of disturbances currently present from
eastern TX into eastern OK are forecast to track northeastward
tonight and into the area in advance of the slowly progressive
long wave trof and attendant cold front. Backing mid/upper level
flow and large scale ascent associated with the disturbances along
with increasing low level convergence via the southwesterly LLJ is
expected to promote the northeastward spread of showers and
thunderstorms now occuring across eastern OK and northwest AR.
Recent runs of the RAP, HRRR and new 00z NAM all support this
scenario with the axis of precipitation bi-secting St. Louis at
12z. Instability has waned dramatically in the wake of the earlier
storms and loss of heating and any additional instability increase
overnight should be largely elevated and only weak. This would
suggest the severe weather threat is rather low and in the isolated
category.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CDT Sun May 10 2015
Have heavily leaned towards the afternoon runs of the HRRR for
convective trends heading into the early evening hours. N-S band of
convection is plowing east at 40-45 kts, and will likely be exiting
eastern sections of our CWA shortly after 00z. After an early
evening lull in activity convection should then return to the
CWA...with threat likely a combination of the activity now
increasing along cold front over eastern KS as well as convection
redeveloping just north of Red River.
Believe that this SE OK activity will be the dominate convection
for our area overnight, as current activity will be intensifying
the low level boundary draped across the ARKLATEX, with this dome
of rain-cooled air providing lift to increasing low level jet that
will be transporting very moist air into the region from the
southern Plains. This area will also be in a favorable area of
upper level divergence tied to RRQ of upper level jet.
Once current line of convection exits area, uncertain about
additional severe weather potential overnight. Current activity
as well as latest upstream convection will be putting a big bite
in the instability that will be available, although large scale
shear of 30-50kts still certainly suggests some severe weather
potential. In addition...while some decent rainfalls are likely
over southern sections of the CWA, believe the aforementioned
outflow boundary will keep the heaviest rain threat anchored over
AR...and south of our CWA.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 431 PM CDT Sun May 10 2015
Convection should press east and exit the region during the day
on Monday as cold front pushes across the CWA. I`ve held onto much
higher PoPs than guidance for the early part of the morning on the
western edge of the expected precip shield (generally from near
Cuba thru STL to near Carlinville), but then quickly wind them
down to the SE of STL during the late morning and early afternoon
hours. Any severe weather potential will be strongly tied to
morning convection trends, but SWODY2 still looks reasonable that
greatest threat will be in our far southeast counties, where the
AMS will stand at least some chance of destabililzing before fropa
occurs.
As unseasonably strong upper level low spins its way across the
Great Lakes Monday night and Tuesday, it will drag much cooler air
into the area. This should result in a dry Tuesday with temps a
bit below average, as highs will primarily be in the 60s. Ridging
in the wake of the departing low will mean more tranquil weather
by midweek, with temperatures moderating into the 70s.
Another upper level system will mean a return of unsettled weather
heading into the latter half of the week. There is a large
discrepency in the medium range solutions regarding the location and
movement of this feature especially heading into next weekend, but
with all solutions suggesting a frontal boundary remaining over
the area forecast will mention a chance of thunderstorms in most
areas during the Thursday-Sunday time frame.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 559 PM CDT Sun May 10 2015
Window of VFR conditions early this evening will give way to a
large area of light rain with MVFR visibilities overnight tonight.
Light rain will end at most TAF sites by around 12Z, however low
end MVFR ceilings will move in after rain ends, then last for
several hours before winds back to westerly and bring in drier air
by around 18Z. MVFR cigs may then last in KSTL metro TAF sites
into Monday afternoon before clearing.
Specifics for KSTL: VFR conditions should last until around 06Z
when light rain will move in. The rain will likely last several
hours, then end by 12Z. Ceilings will then fall into the low end
MVFR or high end IFR range and last until around 18Z. Winds will
back to westerly by then, bringing drier air and MVFR ceilings
into the afternoon. Skies should clear by late afternoon.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
620 PM CDT Sun May 10 2015
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CDT Sun May 10 2015
Have heavily leaned towards the afternoon runs of the HRRR for
convective trends heading into the early evening hours. N-S band of
convection is plowing east at 40-45 kts, and will likely be exiting
eastern sections of our CWA shortly after 00z. After an early
evening lull in activity convection should then return to the
CWA...with threat likely a combination of the activity now
increasing along cold front over eastern KS as well as convection
redeveloping just north of Red River.
Believe that this SE OK activity will be the dominate convection
for our area overnight, as current activity will be intensifying
the low level boundary draped across the ARKLATEX, with this dome
of rain-cooled air providing lift to increasing low level jet that
will be transporting very moist air into the region from the
southern Plains. This area will also be in a favorable area of
upper level divergence tied to RRQ of upper level jet.
Once current line of convection exits area, uncertain about
additional severe weather potential overnight. Current activity
as well as latest upstream convection will be putting a big bite
in the instability that will be available, although large scale
shear of 30-50kts still certainly suggests some severe weather
potential. In addition...while some decent rainfalls are likely
over southern sections of the CWA, believe the aforementioned
outflow boundary will keep the heaviest rain threat anchored over
AR...and south of our CWA.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 431 PM CDT Sun May 10 2015
Convection should press east and exit the region during the day
on Monday as cold front pushes across the CWA. I`ve held onto much
higher PoPs than guidance for the early part of the morning on the
western edge of the expected precip shield (generally from near
Cuba thru STL to near Carlinville), but then quickly wind them
down to the SE of STL during the late morning and early afternoon
hours. Any severe weather potential will be strongly tied to
morning convection trends, but SWODY2 still looks reasonable that
greatest threat will be in our far southeast counties, where the
AMS will stand at least some chance of destabililzing before fropa
occurs.
As unseasonably strong upper level low spins its way across the
Great Lakes Monday night and Tuesday, it will drag much cooler air
into the area. This should result in a dry Tuesday with temps a
bit below average, as highs will primarily be in the 60s. Ridging
in the wake of the departing low will mean more tranquil weather
by midweek, with temperatures moderating into the 70s.
Another upper level system will mean a return of unsettled weather
heading into the latter half of the week. There is a large
discrepency in the medium range solutions regarding the location and
movement of this feature especially heading into next weekend, but
with all solutions suggesting a frontal boundary remaining over
the area forecast will mention a chance of thunderstorms in most
areas during the Thursday-Sunday time frame.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 559 PM CDT Sun May 10 2015
Window of VFR conditions early this evening will give way to a
large area of light rain with MVFR visibilities overnight tonight.
Light rain will end at most TAF sites by around 12Z, however low
end MVFR ceilings will move in after rain ends, then last for
several hours before winds back to westerly and bring in drier air
by around 18Z. MVFR cigs may then last in KSTL metro TAF sites
into Monday afternoon before clearing.
Specifics for KSTL: VFR conditions should last until around 06Z
when light rain will move in. The rain will likely last several
hours, then end by 12Z. Ceilings will then fall into the low end
MVFR or high end IFR range and last until around 18Z. Winds will
back to westerly by then, bringing drier air and MVFR ceilings
into the afternoon. Skies should clear by late afternoon.
Browning
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 66 74 52 69 / 80 80 5 0
Quincy 61 68 46 65 / 70 30 5 0
Columbia 57 69 47 68 / 70 20 5 0
Jefferson City 58 71 47 69 / 70 20 5 0
Salem 68 76 53 68 / 90 80 10 0
Farmington 63 75 50 69 / 80 80 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
541 PM CDT Sat May 9 2015
.UPDATE:
Issued at 538 PM CDT Sat May 9 2015
Increased PoPs to categorical near and ahead of MCV that will
track from southeast Franklin County, Missouri to central
Illinois this evening. Environment just unstable enough to support
a few updrafts. A few weak couplets and funnel clouds have also
been reported which is not surprising given the near shower/storm
environment with increased vorticity near MCV and back winds along
and ahead of the MCV.
CVKING
&&
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CDT Sat May 9 2015
MCV just southwest of metro area to continue lifting very slowly to
the north with showers and a few thunderstorms, which will taper off
from south to north through the early evening hours. Then next round
to approach region from the southwest this evening with chances
increasing during the late evening and overnight hours. We will
see the highest amounts of rainfall over northern portions of
forecast area after midnight.
Byrd
.LONG TERM: (Sunday through Next Saturday)
Issued at 336 PM CDT Sat May 9 2015
On Sunday will see a bit of a break during the morning. However,
could see severe weather during the afternoon and evening as more
vigorous shortwave lifts northeast through region ahead of main
cold front. Decent instability with CAPE in excess of 2000 J/kg
and shear. SPC has forecast area in slight risk with the main
threats being large hail and damaging winds.
The question for Monday is there is time for the atmosphere to
recover ahead of main cold front for another round of severe weather
south and east of the STL metro area. Do think we will see enough of
a recovery with severe storms not out of the question.
As for rainfall, could see upwards of an inch to an inch and
a half of rainfall across the region over the next 48 hours, but
over a prolonged enough period that a flash flood watch is not
warranted at this time.
Then front finally exits region by Monday evening with dry and
cooler conditions expected through mid week. Extended models have
differences in timing of the next weather system, so only made minor
adjustments to the forecast with onset of precipitation a bit later,
by Wednesday night and persisting across the region through the
first part of next weekend.
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1007 AM CDT Sat May 9 2015
Messy forecast once again with rain, stratus and who knows what
else. OOz model runs actually seemed to have a better handle on
the precipitation. The 12z runs have rain everywhere making it
diffucult to pick out specific timing. Weak cold front sagged
south of STL into SE MO producing a NE surface wind overnight.
This likely helped in the startus and fog development overnight.
Current batch of rain associated with the latest short wave
continues to lift east northeast, with a slight weakening trend.
Looks like it will still hit the STL area but should stay out of
UIN. As the front lifts north a south to southeast will kick in
and this help get rid of the low ceilings later in the afternoon.
HRRR has had a pretty good track record with the rain development
and it has rain forming in SW MO this afternoon and weakening it
as ti moves east. Given the more stable conditions over the eastern
part of the state after the morning rain this looks reasonable. Then
if forms another round across SW MO with the next wave and moves
it NE. The trick will be how far this will go. The GFS and WRF
keep it intact and move it across the state overnight so it looks
like some rain mention ovenight will be needed. The front should
lift north bringing a southeast wind and moving the area into more
of a warm sector. While MVFR some ceilings are expected, don`t
think IFR will be as prevalent.
Specifics for KSTL: Looks like the current area of rain will make
it to the terminal. visibilities have dropped to about 2 sm in the
heavier showers. Ceilings should trend upward through the
afternoon, expecialy after the weak front lifts north and the
southeast wind kicks in about 20-21z. Area will be pretty stable
this afternoon so expect afternoon development to hopefully stay
south. Models pretty consistent in bringing a late night/early
morning batch of rain through, but again timing is very difficult.
This fits with the HRRR forming rain over southwest MO about 04z.
Will throw in a VCTS for 08z to 12z. Beyond 12z, models pretty
consistent in developing a line of storms out west Sunday. NAM is
quickest with stuff moving into the area late afternoon with the
GFS slower.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
338 PM CDT Sat May 9 2015
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CDT Sat May 9 2015
MCV just southwest of metro area to continue lifting very slowly to
the north with showers and a few thunderstorms, which will taper off
from south to north through the early evening hours. Then next round
to approach region from the southwest this evening with chances
increasing during the late evening and overnight hours. We will
see the highest amounts of rainfall over northern portions of
forecast area after midnight.
Byrd
.LONG TERM: (Sunday through Next Saturday)
Issued at 336 PM CDT Sat May 9 2015
On Sunday will see a bit of a break during the morning. However,
could see severe weather during the afternoon and evening as more
vigorous shortwave lifts northeast through region ahead of main
cold front. Decent instability with CAPE in excess of 2000 J/kg
and shear. SPC has forecast area in slight risk with the main
threats being large hail and damaging winds.
The question for Monday is there is time for the atmosphere to
recover ahead of main cold front for another round of severe weather
south and east of the STL metro area. Do think we will see enough of
a recovery with severe storms not out of the question.
As for rainfall, could see upwards of an inch to an inch and
a half of rainfall across the region over the next 48 hours, but
over a prolonged enough period that a flash flood watch is not
warranted at this time.
Then front finally exits region by Monday evening with dry and
cooler conditions expected through mid week. Extended models have
differences in timing of the next weather system, so only made minor
adjustments to the forecast with onset of precipitation a bit later,
by Wednesday night and persisting across the region through the
first part of next weekend.
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1007 AM CDT Sat May 9 2015
Messy forecast once again with rain, stratus and who knows what
else. OOz model runs actually seemed to have a better handle on
the precipitation. The 12z runs have rain everywhere making it
diffucult to pick out specific timing. Weak cold front sagged
south of STL into SE MO producing a NE surface wind overnight.
This likely helped in the startus and fog development overnight.
Current batch of rain associated with the latest short wave
continues to lift east northeast, with a slight weakening trend.
Looks like it will still hit the STL area but should stay out of
UIN. As the front lifts north a south to southeast will kick in
and this help get rid of the low ceilings later in the afternoon.
HRRR has had a pretty good track record with the rain development
and it has rain forming in SW MO this afternoon and weakening it
as ti moves east. Given the more stable conditions over the eastern
part of the state after the morning rain this looks reasonable. Then
if forms another round across SW MO with the next wave and moves
it NE. The trick will be how far this will go. The GFS and WRF
keep it intact and move it across the state overnight so it looks
like some rain mention ovenight will be needed. The front should
lift north bringing a southeast wind and moving the area into more
of a warm sector. While MVFR some ceilings are expected, don`t
think IFR will be as prevalent.
Specifics for KSTL: Looks like the current area of rain will make
it to the terminal. visibilities have dropped to about 2 sm in the
heavier showers. Ceilings should trend upward through the
afternoon, expecialy after the weak front lifts north and the
southeast wind kicks in about 20-21z. Area will be pretty stable
this afternoon so expect afternoon development to hopefully stay
south. Models pretty consistent in bringing a late night/early
morning batch of rain through, but again timing is very difficult.
This fits with the HRRR forming rain over southwest MO about 04z.
Will throw in a VCTS for 08z to 12z. Beyond 12z, models pretty
consistent in developing a line of storms out west Sunday. NAM is
quickest with stuff moving into the area late afternoon with the
GFS slower.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
336 PM CDT Sat May 9 2015
.SHORT TERM...(This Evening through Sunday)
Issued at 305 PM CDT SAT MAY 9 2015
Thunderstorm chances will increase through this evening and tonight
as a 50-60kt low level jet sets up along the MO/KS border and
overruns the stationary boundary near the I-44 corridor. Large
amounts of more moist air will spread into the region ahead of a
shortwave trough currently over central OK. Short term forecast
progs show K-index values around 40, well over the baseline of 30
generally needed for heavy rainfall. We`re also seeing tall and
skinny CAPE on RUC forecast soundings. With fairly saturated soils
from previous two nights of rainfall, will be issuing a Flash
Flood Watch for areas along and west of an Osceola to Cassville to
Gainesville line through 1 AM Monday. Later shifts may need to
modify areal coverage and timing.
Severe storm threat will remain on the lower end for hail and
straight line winds, but not zero. Better instability and more
favorable vertical wind shear for rotating storms will remain to our
west, in closer proximity to the main upper low pressure system over
the four corners region.
With better instability and upper level dynamics ahead of the
upper low which finally ejects to the northeast into the central Plains,
severe threat will be higher on Sunday afternoon/evening.
.LONG TERM...(Sunday Night through Saturday)
Issued at 305 PM CDT SAT MAY 9 2015
As the upper low continues to shift northward into the upper
Midwest, a cold front will finally push east of the region Monday
morning and bring a much drier and slightly cooler airmass into
the MO Ozarks/SE KS. We may see a few lingering showers over our
far eastern counties, so will keep storms in the forecast east of a
Warsaw to Cassville line through the morning, and east of a Rolla
to Gainesville line through the afternoon.
Surface high pressure will remain over the region through
Wednesday before another lee side trough sets up over the southern
Rockies ahead of an upper low moving into the southern CA coast
late next week. So expect increasingly stormy conditions from late
next week into the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1257 PM CDT SAT MAY 9 2015
Scattered to numerous showers and thunderstorms will develop and
push northeast through southern Missouri this afternoon and
tonight. MVFR and brief IFR can be expected with any
thunderstorms. Outside of thunderstorms, MVFR ceilings will
scatter out this afternoon. They will then fill back in from later
this evening into the overnight period as moisture increases from
the south. There is the potential for some IFR ceilings around
Branson late tonight, but confidence is low at this point. Another
concern for later tonight is low level wind shear conditions. East
to southeast surface winds will turn to the southeast tonight and
then increase out of the south Sunday morning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...FLASH FLOOD WATCH from 7 PM CDT this evening through late Sunday
night FOR MOZ066-067-077-078-088-089-093>095-101>105.
KS...FLASH FLOOD WATCH from 7 PM CDT this evening through late Sunday
night FOR KSZ073-097-101.
&&
$$
SHORT TERM...Terry
LONG TERM...Terry
AVIATION...Schaumann
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1104 AM CDT Sat May 9 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 345 AM CDT Sat May 9 2015
Patchy dense fog has developed across the area. Most vsbys at this
time are in the 1 to 4 mile range, but there are a hand full of
sites reporting 1/2 mile or less. Will hold off issuing a dense fog
advisory until/unless the patches congeal into something more wide
spread this morning. Temperatures will be highly dependent on how
precipitation develops and overspreads the region today. Current
thinking is that the area of rain with embedded thunderstorms
currently over southwest Missouri will move slowly east-northeast
into our southern zones through 12-14Z, and then will develop
further north and west as we get a little daytime heating and the
upstream shortwave over Oklahoma moves into Missouri. WRF members
as well as the HRRR and RAP are in pretty good agreement with this
scenario, though there are differences in how far north and west the
precipitation will spread. Most likely areas to receive rain will
probably be along and south of a line from Columbia MO to Litchfield
IL, fading quickly further north. Think severe potential will be
limited by instability today as RAP MUCAPE struggles to get above
1000 J/Kg; and when it does this afternoon, it`s pretty much only in
our far southern zones and the deep layer shear is only 20-30kts.
Carney
.LONG TERM: (Tonight through Friday)
Issued at 345 AM CDT Sat May 9 2015
Two wx patterns are expected to tell the story about the wx into
next weekend.
Through Monday, southwest flow aloft will be the rule. Thrown into
the mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system over the southwestern CONUS. Ultimately, this will yield
high PoPs for each day and night period during this stretch, with
many in the likely [60%] category or higher.
Strong storms will be possible this afternoon and early this evening
today. Better severe storm potential remains the case for Sunday,
where moderate instability (1000-2000 J/kg of CAPE) will combine
with 40kts+ of 0-6km bulk shear with a preferred mid-afternoon to
mid-evening time range. If any discrete development occurs,
shear/prop vectors suggest it will be short-lived and likely will
merge into linear convection. Monday continues to look iffy on
severe for area, but somewhat better than it did 24hrs ago, where a
small window will exist both in time (afternoon) and space (eastern
CWA around KSLO) thanks to what should be a very slow moving cold
front by this time.
There remains the potential for localized heavy rainfall in this
synoptic pattern, and indeed, this localized heavy rainfall has
already occurred in spots across our CWA, most notably from Pike
County IL to Gasconade/Osage Counties in MO, but of immediate
concern thru tonight, there is way too much variability and not
enough of a clear signal or focus to target any one specific area
over another. If a FFA is issued, it will probably happen late in
this event after much of the localized heavy rain totals have been
revealed.
This wet period will conclude with passage of a surface cold front
on Monday. Until then, temperatures will remain above average with
MOS max temp values looking reasonable during the day and the warmer
min temp values preferred for nighttime. Favored the much higher
MAV MOS for max temps on Monday with some sunshine expected for most
areas and gusty SW surface winds.
For Tuesday thru Thursday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. While dry
air will be in place on Tuesday and should result in a rare dry day,
already by Thursday, the beginnings of a renewal in SW flow just
upstream and the re-tapping of what seems to be an endless supply of
upper level disturbances from TX and the Southwest are in the works.
Leaned towards an extension of dry wx for much of Wednesday but
could not stem the tide for Thursday, with climo PoPs [25-30%]
preferred given a shift in the pattern already again and some model
differences on how this will occur. Better consensus is achieved
for Friday for the resumption of the wet SW flow aloft pattern and
so went above climo PoPs. Temps look to drop to near average levels
for mid-week but should have no problem getting above average by
late week and next weekend with the building RIDGE aloft nearby.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1007 AM CDT Sat May 9 2015
Messy forecast once again with rain, stratus and who knows what
else. OOz model runs actually seemed to have a better handle on
the precipitation. The 12z runs have rain everywhere making it
diffucult to pick out specific timing. Weak cold front sagged
south of STL into SE MO producing a NE surface wind overnight.
This likely helped in the startus and fog development overnight.
Current batch of rain associated with the latest short wave
continues to lift east northeast, with a slight weakening trend.
Looks like it will still hit the STL area but should stay out of
UIN. As the front lifts north a south to southeast will kick in
and this help get rid of the low ceilings later in the afternoon.
HRRR has had a pretty good track record with the rain development
and it has rain forming in SW MO this afternoon and weakening it
as ti moves east. Given the more stable conditions over the eastern
part of the state after the morning rain this looks reasonable. Then
if forms another round across SW MO with the next wave and moves
it NE. The trick will be how far this will go. The GFS and WRF
keep it intact and move it across the state overnight so it looks
like some rain mention ovenight will be needed. The front should
lift north bringing a southeast wind and moving the area into more
of a warm sector. While MVFR some ceilings are expected, don`t
think IFR will be as prevalent.
Specifics for KSTL: Looks like the current area of rain will make
it to the terminal. visibilities have dropped to about 2 sm in the
heavier showers. Ceilings should trend upward through the
afternoon, expecialy after the weak front lifts north and the
southeast wind kicks in about 20-21z. Area will be pretty stable
this afternoon so expect afternoon development to hopefully stay
south. Models pretty consistent in bringing a late night/early
morning batch of rain through, but again timing is very difficult.
This fits with the HRRR forming rain over southwest MO about 04z.
Will throw in a VCTS for 08z to 12z. Beyond 12z, models pretty
consistent in developing a line of storms out west Sunday. NAM is
quickest with stuff moving into the area late afternoon with the
GFS slower.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
709 AM CDT Sat May 9 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 345 AM CDT Sat May 9 2015
Patchy dense fog has developed across the area. Most vsbys at this
time are in the 1 to 4 mile range, but there are a hand full of
sites reporting 1/2 mile or less. Will hold off issuing a dense fog
advisory until/unless the patches congeal into something more wide
spread this morning. Temperatures will be highly dependent on how
precipitation develops and overspreads the region today. Current
thinking is that the area of rain with embedded thunderstorms
currently over southwest Missouri will move slowly east-northeast
into our southern zones through 12-14Z, and then will develop
further north and west as we get a little daytime heating and the
upstream shortwave over Oklahoma moves into Missouri. WRF members
as well as the HRRR and RAP are in pretty good agreement with this
scenario, though there are differences in how far north and west the
precipitation will spread. Most likely areas to receive rain will
probably be along and south of a line from Columbia MO to Litchfield
IL, fading quickly further north. Think severe potential will be
limited by instability today as RAP MUCAPE struggles to get above
1000 J/Kg; and when it does this afternoon, it`s pretty much only in
our far southern zones and the deep layer shear is only 20-30kts.
Carney
.LONG TERM: (Tonight through Friday)
Issued at 345 AM CDT Sat May 9 2015
Two wx patterns are expected to tell the story about the wx into
next weekend.
Through Monday, southwest flow aloft will be the rule. Thrown into
the mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system over the southwestern CONUS. Ultimately, this will yield
high PoPs for each day and night period during this stretch, with
many in the likely [60%] category or higher.
Strong storms will be possible this afternoon and early this evening
today. Better severe storm potential remains the case for Sunday,
where moderate instability (1000-2000 J/kg of CAPE) will combine
with 40kts+ of 0-6km bulk shear with a preferred mid-afternoon to
mid-evening time range. If any discrete development occurs,
shear/prop vectors suggest it will be short-lived and likely will
merge into linear convection. Monday continues to look iffy on
severe for area, but somewhat better than it did 24hrs ago, where a
small window will exist both in time (afternoon) and space (eastern
CWA around KSLO) thanks to what should be a very slow moving cold
front by this time.
There remains the potential for localized heavy rainfall in this
synoptic pattern, and indeed, this localized heavy rainfall has
already occurred in spots across our CWA, most notably from Pike
County IL to Gasconade/Osage Counties in MO, but of immediate
concern thru tonight, there is way too much variability and not
enough of a clear signal or focus to target any one specific area
over another. If a FFA is issued, it will probably happen late in
this event after much of the localized heavy rain totals have been
revealed.
This wet period will conclude with passage of a surface cold front
on Monday. Until then, temperatures will remain above average with
MOS max temp values looking reasonable during the day and the warmer
min temp values preferred for nighttime. Favored the much higher
MAV MOS for max temps on Monday with some sunshine expected for most
areas and gusty SW surface winds.
For Tuesday thru Thursday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. While dry
air will be in place on Tuesday and should result in a rare dry day,
already by Thursday, the beginnings of a renewal in SW flow just
upstream and the re-tapping of what seems to be an endless supply of
upper level disturbances from TX and the Southwest are in the works.
Leaned towards an extension of dry wx for much of Wednesday but
could not stem the tide for Thursday, with climo PoPs [25-30%]
preferred given a shift in the pattern already again and some model
differences on how this will occur. Better consensus is achieved
for Friday for the resumption of the wet SW flow aloft pattern and
so went above climo PoPs. Temps look to drop to near average levels
for mid-week but should have no problem getting above average by
late week and next weekend with the building RIDGE aloft nearby.
TES
&&
.AVIATION: (For the 12z TAFs through 12z Sunday Morning)
Issued at 642 AM CDT Sat May 9 2015
Widespread IFR flight conditions...primarily due to ceilings AOB
500 FT...locally with visibilities AOB 1/2SM in fog should improve
over the next 2 to 3 hours. Expect rain currently moving into
central Missouri to expand northeast. MVFR/VFR flight conditions
are expected to prevail outside of the pockets of heavier rain.
Embedded thunderstorms will likely briefly drop visibility into
IFR range. Current thinking is that the widespread coverage in rain
will stay along and south of a line from KCOU to K3LF with
scattered showers further north.
The next wave of showers and thunderstorms which is currently over
northern Texas is expected to continue moving northeast into our
area after 00Z. Unsure how low to go at this time, but MVFR flight
conditions are a reasonable staring point as this area of rain with
embedded thunderstorms moves into the area.
Specifics for KSTL:
Expect IFR ceilings at Lambert to improve over the next couple of
hours, though am not extremely confident on the exact timing of
the improvement. Radar estimates the rain with embedded
thunderstorms will move into the terminal between 16-17Z, and this
agrees well with short-range guidance. Think flight conditions
will mainly be MVFR with the rain, but IFR is possible if any of
the pockets of heavier rain associated with thunderstorms moves
over the terminal. Should be a break in the rain this afternoon
after 20Z...and the VCTS in the TAF at this time may be overkill.
However, did not feel comfortable not mentioning something in the
vicinity of the terminal this afternoon given the deep moisture
over the area and the potential for storms to rapidly develop.
The next wave of showers and thunderstorms which is currently over
northern Texas is expected to continue moving northeast into our
area after 00Z. Unsure how low to go at this time, but MVFR flight
conditions are a reasonable staring point as this area of rain with
embedded thunderstorms moves into the area.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
345 AM CDT Sat May 9 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 345 AM CDT Sat May 9 2015
Patchy dense fog has developed across the area. Most vsbys at this
time are in the 1 to 4 mile range, but there are a hand full of
sites reporting 1/2 mile or less. Will hold off issuing a dense fog
advisory until/unless the patches congeal into something more wide
spread this morning. Temperatures will be highly dependent on how
precipitation develops and overspreads the region today. Current
thinking is that the area of rain with embedded thunderstorms
currently over southwest Missouri will move slowly east-northeast
into our southern zones through 12-14Z, and then will develop
further north and west as we get a little daytime heating and the
upstream shortwave over Oklahoma moves into Missouri. WRF members
as well as the HRRR and RAP are in pretty good agreement with this
scenario, though there are differences in how far north and west the
precipitation will spread. Most likely areas to receive rain will
probably be along and south of a line from Columbia MO to Litchfield
IL, fading quickly further north. Think severe potential will be
limited by instability today as RAP MUCAPE struggles to get above
1000 J/Kg; and when it does this afternoon, it`s pretty much only in
our far southern zones and the deep layer shear is only 20-30kts.
Carney
.LONG TERM: (Tonight through Friday)
Issued at 345 AM CDT Sat May 9 2015
Two wx patterns are expected to tell the story about the wx into
next weekend.
Through Monday, southwest flow aloft will be the rule. Thrown into
the mix will be a general southerly flow at the surface, well above
normal levels of moisture thru the column for early May, and a
series of upper level disturbances ejecting from a wound up storm
system over the southwestern CONUS. Ultimately, this will yield
high PoPs for each day and night period during this stretch, with
many in the likely [60%] category or higher.
Strong storms will be possible this afternoon and early this evening
today. Better severe storm potential remains the case for Sunday,
where moderate instability (1000-2000 J/kg of CAPE) will combine
with 40kts+ of 0-6km bulk shear with a preferred mid-afternoon to
mid-evening time range. If any discrete development occurs,
shear/prop vectors suggest it will be short-lived and likely will
merge into linear convection. Monday continues to look iffy on
severe for area, but somewhat better than it did 24hrs ago, where a
small window will exist both in time (afternoon) and space (eastern
CWA around KSLO) thanks to what should be a very slow moving cold
front by this time.
There remains the potential for localized heavy rainfall in this
synoptic pattern, and indeed, this localized heavy rainfall has
already occurred in spots across our CWA, most notably from Pike
County IL to Gasconade/Osage Counties in MO, but of immediate
concern thru tonight, there is way too much variability and not
enough of a clear signal or focus to target any one specific area
over another. If a FFA is issued, it will probably happen late in
this event after much of the localized heavy rain totals have been
revealed.
This wet period will conclude with passage of a surface cold front
on Monday. Until then, temperatures will remain above average with
MOS max temp values looking reasonable during the day and the warmer
min temp values preferred for nighttime. Favored the much higher
MAV MOS for max temps on Monday with some sunshine expected for most
areas and gusty SW surface winds.
For Tuesday thru Thursday, we will see NW flow initially transition
to a building RIDGE overhead from the southeast CONUS. While dry
air will be in place on Tuesday and should result in a rare dry day,
already by Thursday, the beginnings of a renewal in SW flow just
upstream and the re-tapping of what seems to be an endless supply of
upper level disturbances from TX and the Southwest are in the works.
Leaned towards an extension of dry wx for much of Wednesday but
could not stem the tide for Thursday, with climo PoPs [25-30%]
preferred given a shift in the pattern already again and some model
differences on how this will occur. Better consensus is achieved
for Friday for the resumption of the wet SW flow aloft pattern and
so went above climo PoPs. Temps look to drop to near average levels
for mid-week but should have no problem getting above average by
late week and next weekend with the building RIDGE aloft nearby.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1153 PM CDT Fri May 8 2015
Pushed back timing of precip into the afternoon and eve hours. Can
not rule out ongoing precip over swrn MO into OK reaching
STL/SUS/CPS region around sunrise. Otherwise, expect FG to persist
thru the night, tho visbys will likely bounce around thru the
night. Have delayed improvement, but will likely depend on
location of the wrmfnt as it lifts nwd thru the area.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
911 PM MDT SUN MAY 10 2015
.DISCUSSION...
UPDATE FORTHCOMING. AN UPPER TROF ALONG THE CANADIAN BORDER WILL AID
IN THE DEVELOPMENT OF ISOLATED SHOWERS THIS EVENING. RADAR RETURNS
SHOWING THESE SHOWERS DEVELOPING AT THIS TIME. SPC MESOSCALE
ANALYSIS INDICATES POCKETS OF CAPE OF A FEW HUNDRED J/KG WITH
HIGHER VALUES JUST ACROSS THE INTERNATIONAL BOUNDARY. LI VALUES ARE
SLIGHTLY BELOW ZERO. HRRR ANALYSIS KEEPS CONVECTIVE ACTIVITY ONGOING
THROUGH 10Z BEFORE IT DECREASES. AS A RESULT, HAVE PAINTED LOW POPS
ACROSS A BROADER AREA OVERNIGHT. ACTUAL QPF AMOUNTS STILL EXPECTED
TO BE VERY LOW. REMAINDER OF AREA WILL BE DRY. TEMPERATURES LOOK
GOOD.
&&
.AVIATION...
UPDATED 2345Z.
CUMULUS FIELD AND ASSOCIATED ISOLATED SHOWERS WILL
DIMINISH BY 03Z. WEAK UPPER DISTURBANCE MAY RESULT IN ISOLATED
SHOWERS ALONG THE CANADIAN BORDER AFTER 05Z. VFR CONDITIONS PREVAIL
WITH MVFR CONDITIONS POSSIBLE IN THE VICINITY OF SHOWERS.
&&
.PREV DISCUSSION...ISSUED 259 PM MDT SUN MAY 10 2015
SUNDAY THROUGH TUESDAY...COOL CONDITIONS WILL SLOWLY YIELD TO
WARMING TEMPERATURES AS SOME WEAK SHORTWAVES MOVE NEAR THE AREA
AND WILL PRODUCE LIMITED INSTABILITY ACROSS THE REGION. MOST OF
THE INSTABILITY WILL BE SEEN AS INCREASED DEVELOPMENT IN
AFTERNOON CLOUDS WITH SOME SHOWERS OVER THE HIGHER TERRAIN. SOME
ISOLATED SHOWERS WILL BE POSSIBLE ALONG THE ROCKY MOUNTAIN FRONT
AND CANADIAN BORDER SUNDAY EVENING AS A SHORTWAVE MOVES ACROSS
CANADA. ANOTHER SYSTEM WILL MOVE SOUTH OF MONTANA ON MONDAY
AFTERNOON AND COULD PRODUCE SHOWERS OFF THE HIGHER TERRAIN IN
SOUTHWEST MONTANA. OTHERWISE CONDITIONS SHOULD BE RELATIVELY QUIET
AS THE RIDGE OVER THE SOUTHERN UNITED STATE CONTINUES TO INFLUENCE
THE WEATHER PATTERN MORE AND MORE FOR MONTANA. SUK
TUESDAY NIGHT THROUGH SUNDAY...HIGH PRESSURE WILL BE SLIDING EAST
TUESDAY NIGHT AS A BROAD AREA OF LOW PRESSURE AND MOIST SOUTHWEST
FLOW MOVES ACROSS THE PACIFIC NORTHWEST. MOISTURE AHEAD OF THIS
SYSTEM WILL INCREASE THE CHANCE OF SHOWERS ACROSS THE NORTHERN AND
EASTERN PORTIONS OF THE REGION. THE LOW PRESSURE SYSTEM WILL
CONTINUE TO MOVE TOWARDS SOUTHWEST MONTANA AND THE AIRMASS WILL
BECOME A BIT UNSTABLE WEDNESDAY WITH MAINLY THE SOUTHWEST AND
CENTRAL ZONES SEEING SOME THUNDERSTORMS. THE AREA WILL REMAIN RATHER
MOIST THROUGH WEDNESDAY NIGHT BUT WEAK HIGH PRESSURE WILL RETURN
THURSDAY ALONG WITH SOME DRIER CONDITIONS, HOWEVER, THE AIRMASS WILL
REMAIN UNSETTLED AND AFTERNOON SHOWERS WILL BE POSSIBLE...AND
AFTERNOON THUNDERSTORMS ACROSS SOUTHWEST MONTANA. A LOW PRESSURE
SYSTEM WILL MOVE OVER NORTHERN CALIFORNIA FRIDAY AND MOVE INTO
NEVADA DURING THE NIGHT. THIS WILL BRING MOISTURE INTO THE SOUTHWEST
ZONES WHICH WILL THEN SPREAD NORTHEASTWARD. HEIGHTS OVER THE REGION
WILL BEGIN TO DROP AHEAD OF THIS SYSTEM AND SOME INSTABILITY AND
THUNDERSTORM DEVELOPMENT WILL COME WITH THE AFTERNOON AND EVENING
PRECIPITATION. THE LOW PRESSURE CENTER WILL MOVE TOWARDS EXTREME
SOUTHERN SOUTHWEST MONTANA BY THE WEEKEND. THE ASSOCIATED LOW
PRESSURE SYSTEM WILL BRING WRAP AROUND CIRCULATION AND MOISTURE
ACROSS THIS AREA FOR POTENTIALLY HEAVY PRECIPITATION ACROSS PORTIONS
OF SOUTHWEST MONTANA. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 33 63 37 58 / 0 10 20 20
CTB 33 56 32 56 / 10 20 10 20
HLN 35 65 40 63 / 0 10 30 30
BZN 27 62 38 63 / 0 10 20 30
WEY 22 57 30 62 / 0 10 20 40
DLN 32 64 40 64 / 0 20 20 30
HVR 32 65 34 63 / 10 20 10 20
LWT 32 62 37 60 / 10 10 20 30
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
348 PM CDT SAT MAY 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
TONIGHT AND TOMORROW...FORECASTING CONCERNS CENTER ON
THE SEVERE THREAT THIS EVENING...SNOW THREAT IN THE WEST AND
NORTHWEST OVERNIGHT TONIGHT AND SUNDAY...AS WELL AS THE THREAT FOR
HEAVY RAIN AND POSSIBLE FLASH FLOODING CONCERNS. A VIGOROUS UPPER
LEVEL LOW...CURRENTLY OVER SOUTH CENTRAL COLORADO...WILL MIGRATE
INTO NORTHEASTERN COLORADO THROUGH 12Z SUNDAY...BEFORE LIFTING INTO
NORTHERN NEBRASKA BY 00Z MONDAY. IN ASSOCIATION WITH THIS
FEATURE...STRONG TO POSSIBLY SEVERE THUNDERSTORMS WILL BE POSSIBLE
THIS EVENING...FOLLOWED BY THE THREAT FOR HEAVY RAIN
OVERNIGHT...THEN ACCUMULATING SNOWS IN THE EASTERN PANHANDLE AND
NORTHWESTERN SANDHILLS OVERNIGHT. FIRST FOR THE SEVERE THREAT
TONIGHT...A BULGING DRYLINE WILL PUSH FROM SWRN KS INTO NWRN KS BY
06Z SUNDAY. THUNDERSTORMS WILL INITIATE ALONG THIS FEATURE AND
QUICKLY LIFT NORTH INTO SWRN AND SOUTH CENTRAL NEBRASKA. WITH THE
LOW CLOUDS AND COOL CONDS TODAY...THE SEVERE THREAT CONTINUES TO
DIMINISH ACROSS THE SWRN CWA. WITH THIS KIND OF SETUP...DRYLINE TO
THE SOUTH...WARM FRONT TO THE SOUTH...THIS IS TYPICALLY A GOOD SETUP
FOR LARGE HAIL AND THIS WILL BE THE MAIN HAZARD MENTIONED IN THE
HWO. THEN THERE IS THE THREAT FOR SNOW IN THE PANHANDLE AND
NORTHWESTERN SANDHILLS LATER THIS EVENING. ALREADY AS OF 2 PM THIS
AFTERNOON...LIGHT SNOW WAS BEING REPORTED AT CHADRON...WHICH WAS
EARLIER THAN ANTICIPATED WITH THE CURRENT FORECAST. ALREADY HAVE
INCREASED SNOW ACCUMULATIONS IN THE PINE RIDGE AND NERN
PANHANDLE...TO REFLECT AN EARLIER CHANGEOVER OF SNOW. THESE HIGHER
ACCUMS APPG A FOOT WILL BE INCORPORATED IN THE UPDATE OF THE WINTER
STORM WARNING FOR SHERIDAN COUNTY TO BE ISSUED WITH THE AFTERNOON
PACKAGE. SOUTH AND EAST OF SHERIDAN COUNTY...SNOW IS EXPECTED AS
WELL...HOWEVER A MUCH TIGHTER ENVELOPE FOR ACCUMS EXISTS GIVEN
INCREASED MOISTURE AND WARMER TEMPS EXPECTED OVERNIGHT. NO
DOUBT...THE RAIN/SNOW LINE WILL BE VERY TIGHT AND AS IT STANDS RIGHT
NOW...THIS FEATURE RUNS RIGHT THROUGH SHERIDAN COUNTY. TURNING TO
THE HEAVY RAIN THREAT TONIGHT...STRONG MOISTURE ADVECTION CONTINUES
FROM THE SOUTHERN PLAINS INTO NEBRASKA PER 300K MOISTURE TRANSPORT
VECTORS. PW/S WILL INCREASE BY MID EVENING TO 1.1 INCHES AT NORTH
PLATTE...WHICH IS NEAR RECORD FOR THIS TIME OF YEAR. THIS MOISTURE
WILL SHIFT QUICKLY NORTH OVERNIGHT AS THE UPPER LEVEL LOW PUSHES
INTO NORTHEASTERN COLORADO...HOWEVER PW/S WILL STILL BE A HALF TO
2/3RDS OF AN INCH EVEN BEHIND THE DEEPEST AREA OF MOISTURE WHICH
SHIFTS INTO EASTERN NEBRASKA AND SERN SOUTH DAKOTA BY SUNDAY
MORNING. WIDESPREAD PRECIPITATION IS EXPECTED OVERNIGHT...WITH THE
MOST PERSISTENT AREAS TRANSITIONING FROM THE PANHANDLE INTO SWRN AND
CENTRAL NEBRASKA BY LATE EVENING. THIS IS IN RESPONSE TO EXPECTED
CONVECTIVE DEVELOPMENT OVER NORTHWESTERN KS. THE LATEST HRRR AND THE
NAM SOLN FROM THIS MORNING TO A LESSER DEGREE...FOLLOW THIS TREND OF
HEAVIER RAIN SHIFTING INTO SWRN AND CENTRAL NEBRASKA LATER THIS
EVENING...WITH DECREASED QPF IN THE WEST. THIS LULL WILL BE
TEMPORARY HOWEVER. LOOK FOR PCPN TO INCREASE SUNDAY MORNING IN THE
WEST AS DEFORMATION PCPN DEVELOPS ON THE BACK SIDE OF THE EXITING
LOW. THE LATEST 3 HR FLASH FLOOD GUIDANCE IS LESS THAN 1.5 INCHES IN
THE SERN PANHANDLE...KEITH AND PERKINS COUNTIES. THIS AREA HAS
LARGELY ESCAPED THE HEAVY RAIN EARLIER THIS MORNING AND THIS
AFTERNOON. WITH THE HRRR INDICATING HEAVIER RAIN EAST OF THESE
AREAS...WILL FORGO ISSUANCE OF A FLASH FLOOD WATCH FOR THESE AREAS.
FURTHER EAST...3 HR FFG IS AROUND 2 INCHES FOR CUSTER COUNTY SOUTH
OF THE SANDHILLS. AGAIN HRRR QPF/S ARE AROUND 1 TO 2 INCHES IN
CUSTER COUNTY TONIGHT...WHICH IS BELOW FFG SO WILL FORGO A FLASH
FLOOD WATCH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT MAY 9 2015
MODELS VARY SOME WITH AMOUNT OF COLD AIR MOVING THROUGH NORTHERN
NEBRASKA SUNDAY NIGHT AND HAVE GONE WITH COLDER SOLUTION OF THE
NAM. DEFORMATION ZONE WILL CONTINUE TO LIFT THROUGH THE NORTHERN
NEBRASKA SANDHILLS WITH A MIX OF RAIN...RAIN SNOW MIX AND SNOW.
HAVE A COUPLE OF INCHES OF ACCUMULATION WITH THE LIFT ASSOCIATED
WITH THE DEFORMATION ZONE...OVER A VERY SMALL PORTION OF NORTHERN
CHERRY COUNTY. WINDS WILL STAY UP THROUGH MONDAY WITH PRECIP
ENDING THROUGH THE MORNING. LOW TEMPERATURES IN THE 20S NORTHWEST
TO THE MID 30S NORTH CENTRAL...ONEILL. HIGHS IN THE 40S WEST AND
THE 50S SOUTHWEST AND EAST. CLEARING SKIES THROUGH THE DAY WITH
MOSTLY CLEAR SKIES OVER NIGHT. WINDS FALLING OFF AND BECOMING
SOUTH OVER NIGHT WILL ALLOW TEMPERATURES TO FALL TO AROUND
FREEZING. HAVE HELD OFF ON HIGHLIGHTS FOR NOW WITH CURRENT
HIGHLIGHTS OUT. TEMPERATURES REBOUND MONDAY AND TUESDAY AS RIDGE
EXPANDS WEST. WEAK WAVE TO MOVE THROUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING SLIGHT CHANCES RETAINED FOR SOUTHWEST INTO NORTH
CENTRAL NEBRASKA. CHANCES FOR PRECIPITATION RETURN TO THE FORECAST
THURSDAY AND CONTINUE THROUGH THE END OF THE PERIOD AS ENERGY
EJECTS FROM A CLOSED LOW OFF THE PACIFIC COAST AND TEMPERATURES
RISING INTO THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 105 PM CDT SAT MAY 9 2015
SCATTERED SHOWERS CONTINUE TO MOVE NORTH ACROSS CENTRAL AND
WESTERN NEBRASKA WITH IFR CIGS. THUNDERSTORMS MAINLY EXPECTED OVER
SOUTHWEST NEBRASKA THIS AFTERNOON AND EVENING. DO NOT HAVE GREAT
CONFIDENCE WITH THUNDERSTORMS INTO THE KVTN TAF SITE AND HAVE
REMOVED FROM THE GOING TAF. RAIN CONTINUING OVER NIGHT OVER
WESTERN NEBRASKA WITH RAIN CHANGING TO SNOW OR MIXING WITH SNOW
OVER NORTHWEST NEBRASKA PANHANDLE.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SAT MAY 9 2015
THE ONGOING LARGE SCALE AND LONG DURATION HEAVY PRECIP EVENT OVER
THE HIGH PLAINS WILL LEAD TO FLOODING CONCERNS NEXT WEEK ON THE
SOUTH PLATTE RIVER IN SOUTHWEST NEBRASKA INCLUDING
DEUEL...KEITH...AND LINCOLN COUNTIES. AS OF SATURDAY MORNING THE
SOUTH PLATTE RIVER IS ALREADY EXPERIENCING ABOVE NORMAL FLOWS DUE TO
SNOW MELT RUNOFF IN THE FRONT RANGE MOUNTAINS OF COLORADO. LATEST
RIVER FORECAST PROJECTIONS SHOW AN INCREASING THREAT FOR SIGNIFICANT
FLOODING BY THE SECOND HALF OF NEXT WEEK. HOWEVER...HIGH UNCERTAINTY
STILL REMAINS IN THE AMOUNT OF OBSERVED/FORECAST RAINFALL IN
NORTHEAST COLORADO AND WESTERN NEBRASKA...AS WELL AS HOW IT WILL
IMPACT UPSTREAM FLOWS ON THE SOUTH PLATTE RIVER. RIVER FORECASTS
WILL BE CLOSELY MONITORED AND UPDATED AS MORE INFORMATION BECOMES
AVAILABLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM MDT SUNDAY
FOR NEZ022-023-056-094.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT SUNDAY
FOR NEZ004.
&&
$$
SHORT TERM...CLB
LONG TERM...POWER
AVIATION...POWER
HYDROLOGY...MARTIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
111 PM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 1052 AM CDT SAT MAY 9 2015
BEEN TRYING TO GET A BETTER HANDLE ON TODAY/TONIGHT`S SOMEWHAT
COMPLEX SEVERE WEATHER THREAT SINCE WALKING IN THE DOOR 4 HOURS
AGO...AND JUST ISSUED A NEW HAZARDOUS WEATHER OUTLOOK (HWOGID) TO
REFLECT THAT LATEST THINKING. WANT TO MAKE IT CLEAR THOUGH THAT
THE OVERALL EXPECTATIONS FROM THE OVERNIGHT SHIFT AS DISCUSSED
SEVERAL HOURS AGO (AND SEEN BELOW) REMAIN LARGELY ON TRACK.
HERE ARE THE LATEST "RANDOM THOUGHTS" SO FAR THIS MORNING:
1) PER THE SPC 13Z DAY 1 OUTLOOK...THE OVERALL POTENTIAL FOR
WIDESPREAD SEVERE DURING THE NEXT 12-18 HOURS HAS SEEMINGLY
DIMINISHED SOME...AND AGREE WITH THEIR MOVE TO SHUNT THE FORMER
ENHANCED RISK AREA OFF TO THE SOUTHWEST OF THE CWA. GIVEN THAT
WIDESPREAD LOW CLOUDS AND SCATTERED SHOWERS/SOME MAINLY NON-SEVERE
STORMS ARE EXPECTED TO DOMINATE THE AREA THROUGH THE MAJORITY OF
THE DAY...IT WILL BE VERY DIFFICULT TO DESTABILIZE MUCH...AND NOT
SURPRISINGLY THE LATEST RAP 13 INDICATES NEARLY THE ENTIRE CWA
MAKING IT THROUGH AT LEAST THE 4-6 PM TIME FRAME WITH NO MORE THAN
500 J/KG CAPE TO WORK WITH...AND EVEN VALUES THAT HIGH MAINLY
CONFINED TO KS ZONES ONLY.
2) THE MAIN QUESTION FOR THE DAYTIME HOURS WILL BE WHETHER OR NOT
THE EXPANSIVE LINE OF SHOWERS/STORMS CURRENTLY ORIENTED NW-SE
ACROSS WESTERN KS WILL HOLD TOGETHER AS IT EVENTUALLY ENTERS THE
CWA FROM MID-DAY ONWARD. WHILE THIS APPEARS FAIRLY LIKELY TO HOLD
TOGETHER AND PROVIDE SOME GOOD RAIN CHANCES FOR THE
AFTERNOON...ANY SEVERE THREAT WOULD SEEMINGLY BE PRETTY LIMITED
BARRING SOME UNEXPECTED CHANGES.
3) IT STILL APPEARS THE MAIN WINDOW OF OPPORTUNITY FOR POTENTIAL
SEVERE ACTIVITY WILL PROBABLY FOCUS THIS EVENING/TONIGHT MAINLY
BETWEEN THE 7PM-2AM TIME FRAME AND MAINLY ONLY AS FAR NORTH AS THE
I-80 CORRIDOR...AS THE MAIN BATCH OF UPPER LEVEL ENERGY FINALLY
STARTS TO PUSH OUT OF EASTERN COLORADO AND THE LOW-LEVEL
INSTABILITY AXIS AND SURFACE WARM FRONT STARTS TO SHIFT NORTH INTO
THE CWA. EVEN SO...THE RAP13 SUGGESTS THAT CAPE VALUES WILL
PROBABLY STRUGGLE TO EXCEED 1000 J/KG IN MOST AREAS.
HOWEVER...GIVEN THE IMPRESSIVE SHEAR EVEN AFTER NIGHTFALL (DEEP
LAYER VALUES 40-50KT AND LOW- LEVEL 0-1KM VALUES GENERALLY
25-35KT)...THE POTENTIAL FOR AT LEAST BRIEF TORNADO POTENTIAL
COULD LAST A BIT LATER THAN USUAL INTO THE NIGHT...ESPECIALLY
NEAR/SOUTH OF THE STATE LINE. OF COURSE...MUCH OF THIS POSSIBLE
TORNADO POTENTIAL DEPENDS ON MODE...AND WHETHER WE SEE A FEW SEMI-
DISCRETE SUPERCELLS (MORE FAVORABLE) OR WHETHER IT IS MAINLY A
"MESSY" LINEAR OR CLUSTER MODE (LESS FAVORABLE).
4) TEMPERATURE-WISE...NUDGED DOWN HIGHS GENERALLY 3-4 DEGREES IN
MOST AREAS AND POTENTIALLY NOT ENOUGH...BUT NOW GENERALLY CALLING
FOR A RANGE FROM ONLY UPPER 50S NORTHWEST TO POSSIBLY UPPER 60S
SOUTHEAST. OBVIOUSLY NOT A GREAT WARMING SETUP UNDER THE
WIDESPREAD LOW CLOUDS AND EASTERLY FLOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT SAT MAY 9 2015
MAP ANALYSIS INDICATES AN UPPER TROPOSPHERIC LOW OVER THE
SOUTHWESTERN CONUS...CURRENTLY APPROACHING THE FOUR CORNERS
REGION. UPPER TROPOSPHERIC RIDGING IS ALSO NOTED OVER THE EASTERN
CONUS. ENHANCED UPPER TROPOSPHERIC FLOW EXTENDS FORM THE SOUTHERN
ROCKIES...NORTHEAST INTO SOUTHEASTERN CANADA. UPPER TROPOSPHERIC
FLOW OVER OUR AREA MAXES OUT AT AROUND 80KTS NEAR 34000FT AGL PER
00Z SOUNDING DATA FROM KOAX AND KLBF. AT THE SURFACE...AN AREA OF
HIGH BAROMETRIC PRESSURE IS NOTED OVER THE NORTHERN PLAINS...AND
AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER EASTERN NEW MEXICO.
AS A RESULT...THE BOUNDARY-LAYER WIND FIELD ACROSS OUR AREA
REMAINS FROM THE EAST/NORTHEAST.
GUIDANCE SUGGESTS THE UPPER TROPOSPHERIC LOW OVER THE
SOUTHWESTERN CONUS WILL MOVE NORTHEAST THROUGH THE NEXT 24
HOURS...LIKELY RESIDING OVER THE CENTRAL HIGH PLAINS BY 00Z THIS
EVENING...AND OVER THE CENTRAL PLAINS BY 12Z SUNDAY. THIS WILL
HELP MAINTAIN UPPER TROPOSPHERIC FLOW ON THE ORDER OF ~80KTS
ACROSS THE REGION THROUGH TONIGHT. AT THE SURFACE...THE AREA OF
LOW BAROMETRIC PRESSURE OVER EASTERN NEW MEXICO IS EXPECTED MOVE
NORTHEAST...ALONG WITH THE UPPER TROPOSPHERIC LOW...THROUGH THE
NEXT 24 HOURS. THIS SURFACE LOW IS EXPECTED TO RESIDE OVER EASTERN
COLORADO BY 00Z THIS EVENING...AND OVER CENTRAL NEBRASKA BY 12Z
SUNDAY. THIS SHOULD ALLOW A WARM FRONT AT THE SURFACE TO EXTEND
EAST FROM THE LOW INTO NORTHERN KANSAS BY 00Z THIS EVENING...WITH
THIS WARM FRONT THEN EXPECTED TO SURGE NORTH INTO THE MISSOURI
RIVER VALLEY OVERNIGHT TONIGHT. THIS SHOULD PROMOTE INCREASED
SOUTH/SOUTHEASTERLY BOUNDARY-LAYER FLOW ACROSS OKLAHOMA AND KANSAS
TODAY...WITH THIS SOUTH/SOUTHEASTERLY BOUNDARY-LAYER FLOW MOVING
INTO SOUTHERN AND EASTERN PORTIONS OF NEBRASKA TONIGHT.
SEVERE WEATHER REMAINS POSSIBLE ACROSS PORTIONS OF THE CWA LATER
TODAY...BUT AT THIS TIME IT APPEARS THE PRIMARY SEVERE WEATHER
THREAT FOR OUR AREA WILL HOLD OFF UNTIL CLOSER TO 00Z THIS EVENING
BEFORE CONTINUING INTO THE OVERNIGHT HOURS TONIGHT.
GUIDANCE SUGGESTS INCREASED THERMAL ADVECTION AND RESULTANT OMEGA
AHEAD OF THE APPROACHING UPPER TROPOSPHERIC LOW WILL PROMOTE
PRECIPITATION PRODUCTION ACROSS OUR AREA STARTING THIS
MORNING...SPREADING FROM SOUTHWEST TO NORTHEAST. THIS IS A
SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS
AND EC...AS WELL AS SIMULATED REFLECTIVITY FROM THE 4KM WRF-NMM
AND HRRR. IT REMAINS UNCLEAR HOWEVER JUST HOW ROBUST THIS DAYTIME
CONVECTION WILL BE ACROSS OUR AREA. WITH GUIDANCE KEEPING THE WARM
FRONT TO OUR SOUTH FOR THE MOST PART THROUGH TODAY...LOWER
TROPOSPHERIC MOISTURE WILL BE RELATIVELY LIMITED. ADD TO THAT A
SOLID SHIELD OF STRATUS IS EXPECTED TO PERSIST OVER OUR AREA NORTH
OF THE WARM FRONT...WHICH WILL CERTAINLY KEEP TEMPERATURE READINGS
COOLER. GIVEN ALL THIS...POTENTIAL ENERGY VALUES ACROSS OUR AREA
THROUGH THIS AFTERNOON ARE EXPECTED TO REMAIN UNDER 1000J/KG
THROUGH 00Z...WITH ANYTHING NEAR 1000J/KG EXPECTED TO REMAIN SOUTH
OF HIGHWAY-6. IT IS WORTH MENTIONING THAT THE AFOREMENTIONED
ENHANCED UPPER TROPOSPHERIC FLOW WILL HELP PROMOTE DEEP-LAYER BULK
SHEAR VALUES OF 40-50KTS ACROSS MUCH OF OUR AREA THIS
AFTERNOON...BUT THE SOMEWHAT LIMITED POTENTIAL ENERGY VALUES
SHOULD KEEP THE THREAT OF SEVERE HAIL AND STRONG STRAIGHT-LINE
WIND ACROSS ANY PORTION OF OUR AREA TO AN ISOLATED BASIS THROUGH
THIS AFTERNOON...AND AGAIN SHOULD BE CONFINED TO LOCATIONS
PRIMARILY SOUTH OF HIGHWAY-6. AS FOR THE TORNADIC THREAT THROUGH
THIS AFTERNOON...WITH THE WARM FRONT REMAINING TO OUR SOUTH FOR
THE MOST PART AND THE LOWER-TROPOSPHERIC WIND FIELD REMAINING MORE
FROM THE EAST ACROSS OUR AREA...ITS HARD TO GET OVERLY EXCITED
ABOUT THE TREAT FOR TORNADOES THROUGH 00Z. THE ONLY EXCEPTION IS
ACROSS OUR EXTREME SOUTH IN THE VICINITY OF THE WARM FRONT WHERE
LOWER TROPOSPHERIC HORIZONTAL VORTICITY WILL BE LOCALLY MAXIMIZED
FOR ANY STORM TRACKING NORTHEAST ACROSS IT.
THINGS DO TURN MORE INTERESTING THIS EVENING AND INTO THE
OVERNIGHT HOURS AS THE WARM FRONT SURGES NORTHWARD...THUS
RESULTING IN NOTICEABLE LOWER TROPOSPHERIC MOISTURE FLUX ACROSS
THE AREA. IN ADDITION...UPPER TROPOSPHERIC LAPSE RATES SHOULD ALSO
INCREASE DRAMATICALLY AS THE UPPER TROPOSPHERIC LOW MOVES
OVERHEAD. GUIDANCE RESPONDS BY PROVIDING POTENTIAL ENERGY VALUES
OF 1000-2000J/KG AS FAR NORTH AS I-80. IN ADDITION...DEEP-LAYER
SHEAR IN EXCESS OF 50KTS IS EXPECTED TO PERSIST OVER MOST ALL OF
THE CWA TONIGHT. ADD TO THAT A 40-50KT LOW LEVEL AXIS JUST ABOVE
THE BOUNDARY LAYER IS EXPECTED TO DEVELOP AND PERSIST ACROSS
SOUTHERN PORTIONS OF THE CWA AROUND AND AFTER 00Z...THUS ALLOWING
FOR A SPIKE IN LOWER TROPOSPHERIC HORIZONTAL VORTICITY AND
RESULTANT SRH OF 200-250M^2^-2. GIVEN THIS...IT APPEARS THE THREAT
FOR LARGE HAIL...STRONG STRAIGHT-LINE WIND AND TORNADIC ACTIVITY
WILL INCREASE ACROSS PORTIONS OF OUR AREA AROUND OR AFTER
00Z...PRIMARILY SOUTH OF I-80.
PERSISTENT THERMAL ADVECTION ALONG THE AFOREMENTIONED LOW LEVEL
JET AXIS SHOULD THEN HELP MAINTAIN CONVECTION THROUGH MUCH OF THE
OVERNIGHT HOURS...WITH CONVECTION LIKELY CONGEALING INTO A LINEAR
MCS ACROSS OUR EAST/SOUTHEASTERN CWA BEFORE MARCHING EAST INTO THE
MISSOURI RIVER VALLEY AROUND SUNRISE SUNDAY. SO ALTHOUGH THE
TORNADIC THREAT SHOULD DIMINISH TOWARDS 03Z AS THE CONVECTION
BECOMES INCREASINGLY ELEVATED...THE THREAT FOR LARGE HAIL AND
STRONG STRAIGHT-LINE WIND COULD PERSIST THROUGH EARLY SUNDAY
MORNING UNTIL DEEP CONVECTION CLEARS OUR AREA TO THE EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 338 AM CDT SAT MAY 9 2015
ALOFT: THE WRN USA TROF WILL REMAIN LOCKED IN. LOW PRES WILL BE
OVER WRN NEB AT 12Z/SUN WITH THE DRY SLOT ALREADY OVER THE FCST
AREA. A TROF WILL LINGER INTO MON AS THIS LOW DEPARTS FOR THE UPR
MIDWEST. HEIGHTS WILL RISE TUE AS A SHORTWAVE RIDGE OVERTAKES THE
REGION. DEEP SW FLOW WILL DEVELOP WED AND THEN PERSIST FOR SEVERAL
DAYS THE WRN USA TROF RELOADS. EXPECT MULTIPLE LOW-AMPLITUDE
SHORTWAVE TROFS TO EJECT OUT OF THE MEAN TROF...MODULATING TSTM
POTENTIAL. THE LOW- AMPLITUDE NATURE RESULTS IN LOW PREDICTABILITY
AND CONFIDENCE THIS FAR OUT.
SURFACE: LOW PRES WILL BE CROSSING NEB SUN MORNING WITH A STRONG
COOL FRONT SWEEPING THRU THE REGION. THIS LOW WILL HEAD FOR THE
UPR MIDWEST SUN-MON. HIGH PRES FORMS AND EXPANDS OVER THE CNTRL
PLAINS MON INTO MON NIGHT. THIS HIGH WILL SHIFT E OF THE REGION
TUE WITH RETURN FLOW AND A NEW LEE-SIDE TROF DEVELOPING.
UNCERTAINTY INCREASES TUE THRU THE REST OF THE FCST. IT CURRENTLY
LOOKS LIKE A WARM FRONT WILL FORM AND LIFT N OF THE FCST AREA TUE
OR WED. THE STRONG FRONT THAT MOVES THRU SUN WILL BECOME
STATIONARY FROM THE GULF COAST INTO THE SRN PLAINS. THE TAIL END
OF THIS FRONT MAY ALSO LIFT N. BOTTOM LINE IS HIGH PRES WILL
DOMINATE THE ERN USA FOR SEVERAL DAYS WITH LOW PRES OVER THE W. SO
EXPECT GULF MOISTURE TO RETURN N WITH MULTIPLE CHANCES FOR TSTMS.
SOME DAILY DETAILS...
SUN: A CHANGEABLE DAY. THE MOST SUN WILL BE S AND E OF THE TRI-
CITIES. CAN`T RULE OUT A LITTLE LIGHT RAIN N AND W OF THE TRI-
CITIES ON THE SE FRINGE OF THE COMMAHEAD PRECIP SHIELD. BECOMING
WINDY. W WINDS WILL GUST 30-35 KTS.
HIGH TEMPS ARE TOUGH WITH DRY SLOT/COOL FRONTAL PASSAGE/CAA.
MON: A VERY COOL DAY IN THE COLD SECTOR. HIGHS WON`T GEN OUT OF
THE 50S OVER S-CNTRL NEB. A POTENT SHORTWAVE TROF BUT MODELS ARE
CURRENTLY NOT INDICATING ENOUGH MOISTURE TO PRODUCE SHWRS. THE
COLD AIR ALOFT AND DEEP MIXING WILL RESULT IN ANOTHER WINDY DAY.
NW WINDS GUST 30-35 KTS. LOTS OF STRATOCU...ESPECIALLY N OF HWY 6.
MON NIGHT: NEED TO WATCH FROST/FREEZE POTENTIAL...ESPECIALLY N
AND W OF THE TRI-CITIES. THE PLATTE RIVER VALLEY IN DAWSON COUNTY
AND THE N AND MIDDLE LOUP RIVER VALLEY`S WILL BE MOST SUSCEPTIBLE.
TUE: A NICE DAY WITH GOOD TEMP RECOVERY AND LIGHTER WINDS.
WED-FRI: UNCERTAINTY WITH NO SIGNIFICANT LOW PRES...BUT
DIFFERENTIAL ADVECTION WILL RESULT IN GULF MOISTURE AND THE
ELEVATED MIXED LAYER OVERTAKING THE AREA WED. SCT TSTMS WILL BE
PRIMARILY DRIVEN BY PULSES OF WAA/CONVERGENCE ASSOCIATED WITH THE
LOW-LVL JET AND/OR TSTMS THAT DEVELOP WITHIN THE LEE-SIDE TROF AND
MEANDER E INTO THE FCST AREA.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 111 PM CDT SAT MAY 9 2015
GIVEN THAT THE MAJORITY OF THE PERIOD IS EXPECTED TO FEATURE
SCATTERED TO WIDESPREAD SHOWER/THUNDERSTORM ACTIVITY AND MVFR/IFR
(MAYBE EVEN BRIEFLY LIFR) CEILING/VISIBILITY...THERE IS LOW
CONFIDENCE IN DETAILS ESPECIALLY BEYOND THE FIRST 6 HOURS. AS IT
CURRENTLY STANDS THOUGH...THERE APPEARS TO BE LITTLE CHANCE OF A
CONFIDENT RETURN TO OUTRIGHT-VFR CONDITIONS UNTIL THE MID-LATE
MORNING HOURS OF SUNDAY AS A COLD FRONT MOVES THROUGH.
FOCUSING FIRST ON THESE FIRST 4-6 HOURS...PREDOMINANTLY MVFR
CEILING/VISIBILITY WILL PREVAIL IN OFF-AND-ON RAIN SHOWERS...WITH
IFR CONDITIONS MORE LIKELY AT KEAR AS HANDLED IN A TEMPO GROUP.
FROM LATE THIS AFTERNOON INTO THIS EVENING...MORE WIDESPREAD
THUNDERSTORM ACTIVITY IS LIKELY...AND FOR NOW HAVE SIMPLY
BLANKETED THE 22Z-12Z TIME FRAME WITH A VICINITY THUNDERSTORM
(VCTS) MENTION...WITH A VICINITY SHOWER (VCSH) MENTION FOLLOWING
FROM 12Z-15Z. WILL DEFER TO LATER FORECASTS TO INSERT NECESSARY
MORE PREVAILING/TEMPO DETAILS AS NEEDED. ALTHOUGH THE RISK IS
FAIRLY MINIMAL...A MARGINALLY SEVERE STORM WITH HAIL TO AROUND
UP TO AROUND QUARTER SIZE AND GUSTY WINDS CANNOT BE RULED OUT.
WIND-WISE...SUSTAINED SPEEDS WILL LARGELY AVERAGE 10-15KT WITH
SLIGHTLY HIGHER GUSTS THROUGH THE PERIOD...AS DIRECTION
GRADUALLY TRANSITIONS FROM EAST...TO SOUTHEAST...TO SOUTH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...BRYANT
LONG TERM...HALBLAUB
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1055 AM CDT SAT MAY 9 2015
.UPDATE...
ISSUED AT 1052 AM CDT SAT MAY 9 2015
BEEN TRYING TO GET A BETTER HANDLE ON TODAY/TONIGHT`S SOMEWHAT
COMPLEX SEVERE WEATHER THREAT SINCE WALKING IN THE DOOR 4 HOURS
AGO...AND JUST ISSUED A NEW HAZARDOUS WEATHER OUTLOOK (HWOGID) TO
REFLECT THAT LATEST THINKING. WANT TO MAKE IT CLEAR THOUGH THAT
THE OVERALL EXPECTATIONS FROM THE OVERNIGHT SHIFT AS DISCUSSED
SEVERAL HOURS AGO (AND SEEN BELOW) REMAIN LARGELY ON TRACK.
HERE ARE THE LATEST "RANDOM THOUGHTS" SO FAR THIS MORNING:
1) PER THE SPC 13Z DAY 1 OUTLOOK...THE OVERALL POTENTIAL FOR
WIDESPREAD SEVERE DURING THE NEXT 12-18 HOURS HAS SEEMINGLY
DIMINISHED SOME...AND AGREE WITH THEIR MOVE TO SHUNT THE FORMER
ENHANCED RISK AREA OFF TO THE SOUTHWEST OF THE CWA. GIVEN THAT
WIDESPREAD LOW CLOUDS AND SCATTERED SHOWERS/SOME MAINLY NON-SEVERE
STORMS ARE EXPECTED TO DOMINATE THE AREA THROUGH THE MAJORITY OF
THE DAY...IT WILL BE VERY DIFFICULT TO DESTABILIZE MUCH...AND NOT
SURPRISINGLY THE LATEST RAP 13 INDICATES NEARLY THE ENTIRE CWA
MAKING IT THROUGH AT LEAST THE 4-6 PM TIME FRAME WITH NO MORE THAN
500 J/KG CAPE TO WORK WITH...AND EVEN VALUES THAT HIGH MAINLY
CONFINED TO KS ZONES ONLY.
2) THE MAIN QUESTION FOR THE DAYTIME HOURS WILL BE WHETHER OR NOT
THE EXPANSIVE LINE OF SHOWERS/STORMS CURRENTLY ORIENTED NW-SE
ACROSS WESTERN KS WILL HOLD TOGETHER AS IT EVENTUALLY ENTERS THE
CWA FROM MID-DAY ONWARD. WHILE THIS APPEARS FAIRLY LIKELY TO HOLD
TOGETHER AND PROVIDE SOME GOOD RAIN CHANCES FOR THE
AFTERNOON...ANY SEVERE THREAT WOULD SEEMINGLY BE PRETTY LIMITED
BARRING SOME UNEXPECTED CHANGES.
3) IT STILL APPEARS THE MAIN WINDOW OF OPPORTUNITY FOR POTENTIAL
SEVERE ACTIVITY WILL PROBABLY FOCUS THIS EVENING/TONIGHT MAINLY
BETWEEN THE 7PM-2AM TIME FRAME AND MAINLY ONLY AS FAR NORTH AS THE
I-80 CORRIDOR...AS THE MAIN BATCH OF UPPER LEVEL ENERGY FINALLY
STARTS TO PUSH OUT OF EASTERN COLORADO AND THE LOW-LEVEL
INSTABILITY AXIS AND SURFACE WARM FRONT STARTS TO SHIFT NORTH INTO
THE CWA. EVEN SO...THE RAP13 SUGGESTS THAT CAPE VALUES WILL
PROBABLY STRUGGLE TO EXCEED 1000 J/KG IN MOST AREAS.
HOWEVER...GIVEN THE IMPRESSIVE SHEAR EVEN AFTER NIGHTFALL (DEEP
LAYER VALUES 40-50KT AND LOW- LEVEL 0-1KM VALUES GENERALLY
25-35KT)...THE POTENTIAL FOR AT LEAST BRIEF TORNADO POTENTIAL
COULD LAST A BIT LATER THAN USUAL INTO THE NIGHT...ESPECIALLY
NEAR/SOUTH OF THE STATE LINE. OF COURSE...MUCH OF THIS POSSIBLE
TORNADO POTENTIAL DEPENDS ON MODE...AND WHETHER WE SEE A FEW SEMI-
DISCRETE SUPERCELLS (MORE FAVORABLE) OR WHETHER IT IS MAINLY A
"MESSY" LINEAR OR CLUSTER MODE (LESS FAVORABLE).
4) TEMPERATURE-WISE...NUDGED DOWN HIGHS GENERALLY 3-4 DEGREES IN
MOST AREAS AND POTENTIALLY NOT ENOUGH...BUT NOW GENERALLY CALLING
FOR A RANGE FROM ONLY UPPER 50S NORTHWEST TO POSSIBLY UPPER 60S
SOUTHEAST. OBVIOUSLY NOT A GREAT WARMING SETUP UNDER THE
WIDESPREAD LOW CLOUDS AND EASTERLY FLOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 338 AM CDT SAT MAY 9 2015
MAP ANALYSIS INDICATES AN UPPER TROPOSPHERIC LOW OVER THE
SOUTHWESTERN CONUS...CURRENTLY APPROACHING THE FOUR CORNERS
REGION. UPPER TROPOSPHERIC RIDGING IS ALSO NOTED OVER THE EASTERN
CONUS. ENHANCED UPPER TROPOSPHERIC FLOW EXTENDS FORM THE SOUTHERN
ROCKIES...NORTHEAST INTO SOUTHEASTERN CANADA. UPPER TROPOSPHERIC
FLOW OVER OUR AREA MAXES OUT AT AROUND 80KTS NEAR 34000FT AGL PER
00Z SOUNDING DATA FROM KOAX AND KLBF. AT THE SURFACE...AN AREA OF
HIGH BAROMETRIC PRESSURE IS NOTED OVER THE NORTHERN PLAINS...AND
AN AREA OF LOW BAROMETRIC PRESSURE EXISTS OVER EASTERN NEW MEXICO.
AS A RESULT...THE BOUNDARY-LAYER WIND FIELD ACROSS OUR AREA
REMAINS FROM THE EAST/NORTHEAST.
GUIDANCE SUGGESTS THE UPPER TROPOSPHERIC LOW OVER THE
SOUTHWESTERN CONUS WILL MOVE NORTHEAST THROUGH THE NEXT 24
HOURS...LIKELY RESIDING OVER THE CENTRAL HIGH PLAINS BY 00Z THIS
EVENING...AND OVER THE CENTRAL PLAINS BY 12Z SUNDAY. THIS WILL
HELP MAINTAIN UPPER TROPOSPHERIC FLOW ON THE ORDER OF ~80KTS
ACROSS THE REGION THROUGH TONIGHT. AT THE SURFACE...THE AREA OF
LOW BAROMETRIC PRESSURE OVER EASTERN NEW MEXICO IS EXPECTED MOVE
NORTHEAST...ALONG WITH THE UPPER TROPOSPHERIC LOW...THROUGH THE
NEXT 24 HOURS. THIS SURFACE LOW IS EXPECTED TO RESIDE OVER EASTERN
COLORADO BY 00Z THIS EVENING...AND OVER CENTRAL NEBRASKA BY 12Z
SUNDAY. THIS SHOULD ALLOW A WARM FRONT AT THE SURFACE TO EXTEND
EAST FROM THE LOW INTO NORTHERN KANSAS BY 00Z THIS EVENING...WITH
THIS WARM FRONT THEN EXPECTED TO SURGE NORTH INTO THE MISSOURI
RIVER VALLEY OVERNIGHT TONIGHT. THIS SHOULD PROMOTE INCREASED
SOUTH/SOUTHEASTERLY BOUNDARY-LAYER FLOW ACROSS OKLAHOMA AND KANSAS
TODAY...WITH THIS SOUTH/SOUTHEASTERLY BOUNDARY-LAYER FLOW MOVING
INTO SOUTHERN AND EASTERN PORTIONS OF NEBRASKA TONIGHT.
SEVERE WEATHER REMAINS POSSIBLE ACROSS PORTIONS OF THE CWA LATER
TODAY...BUT AT THIS TIME IT APPEARS THE PRIMARY SEVERE WEATHER
THREAT FOR OUR AREA WILL HOLD OFF UNTIL CLOSER TO 00Z THIS EVENING
BEFORE CONTINUING INTO THE OVERNIGHT HOURS TONIGHT.
GUIDANCE SUGGESTS INCREASED THERMAL ADVECTION AND RESULTANT OMEGA
AHEAD OF THE APPROACHING UPPER TROPOSPHERIC LOW WILL PROMOTE
PRECIPITATION PRODUCTION ACROSS OUR AREA STARTING THIS
MORNING...SPREADING FROM SOUTHWEST TO NORTHEAST. THIS IS A
SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL GFS
AND EC...AS WELL AS SIMULATED REFLECTIVITY FROM THE 4KM WRF-NMM
AND HRRR. IT REMAINS UNCLEAR HOWEVER JUST HOW ROBUST THIS DAYTIME
CONVECTION WILL BE ACROSS OUR AREA. WITH GUIDANCE KEEPING THE WARM
FRONT TO OUR SOUTH FOR THE MOST PART THROUGH TODAY...LOWER
TROPOSPHERIC MOISTURE WILL BE RELATIVELY LIMITED. ADD TO THAT A
SOLID SHIELD OF STRATUS IS EXPECTED TO PERSIST OVER OUR AREA NORTH
OF THE WARM FRONT...WHICH WILL CERTAINLY KEEP TEMPERATURE READINGS
COOLER. GIVEN ALL THIS...POTENTIAL ENERGY VALUES ACROSS OUR AREA
THROUGH THIS AFTERNOON ARE EXPECTED TO REMAIN UNDER 1000J/KG
THROUGH 00Z...WITH ANYTHING NEAR 1000J/KG EXPECTED TO REMAIN SOUTH
OF HIGHWAY-6. IT IS WORTH MENTIONING THAT THE AFOREMENTIONED
ENHANCED UPPER TROPOSPHERIC FLOW WILL HELP PROMOTE DEEP-LAYER BULK
SHEAR VALUES OF 40-50KTS ACROSS MUCH OF OUR AREA THIS
AFTERNOON...BUT THE SOMEWHAT LIMITED POTENTIAL ENERGY VALUES
SHOULD KEEP THE THREAT OF SEVERE HAIL AND STRONG STRAIGHT-LINE
WIND ACROSS ANY PORTION OF OUR AREA TO AN ISOLATED BASIS THROUGH
THIS AFTERNOON...AND AGAIN SHOULD BE CONFINED TO LOCATIONS
PRIMARILY SOUTH OF HIGHWAY-6. AS FOR THE TORNADIC THREAT THROUGH
THIS AFTERNOON...WITH THE WARM FRONT REMAINING TO OUR SOUTH FOR
THE MOST PART AND THE LOWER-TROPOSPHERIC WIND FIELD REMAINING MORE
FROM THE EAST ACROSS OUR AREA...ITS HARD TO GET OVERLY EXCITED
ABOUT THE TREAT FOR TORNADOES THROUGH 00Z. THE ONLY EXCEPTION IS
ACROSS OUR EXTREME SOUTH IN THE VICINITY OF THE WARM FRONT WHERE
LOWER TROPOSPHERIC HORIZONTAL VORTICITY WILL BE LOCALLY MAXIMIZED
FOR ANY STORM TRACKING NORTHEAST ACROSS IT.
THINGS DO TURN MORE INTERESTING THIS EVENING AND INTO THE
OVERNIGHT HOURS AS THE WARM FRONT SURGES NORTHWARD...THUS
RESULTING IN NOTICEABLE LOWER TROPOSPHERIC MOISTURE FLUX ACROSS
THE AREA. IN ADDITION...UPPER TROPOSPHERIC LAPSE RATES SHOULD ALSO
INCREASE DRAMATICALLY AS THE UPPER TROPOSPHERIC LOW MOVES
OVERHEAD. GUIDANCE RESPONDS BY PROVIDING POTENTIAL ENERGY VALUES
OF 1000-2000J/KG AS FAR NORTH AS I-80. IN ADDITION...DEEP-LAYER
SHEAR IN EXCESS OF 50KTS IS EXPECTED TO PERSIST OVER MOST ALL OF
THE CWA TONIGHT. ADD TO THAT A 40-50KT LOW LEVEL AXIS JUST ABOVE
THE BOUNDARY LAYER IS EXPECTED TO DEVELOP AND PERSIST ACROSS
SOUTHERN PORTIONS OF THE CWA AROUND AND AFTER 00Z...THUS ALLOWING
FOR A SPIKE IN LOWER TROPOSPHERIC HORIZONTAL VORTICITY AND
RESULTANT SRH OF 200-250M^2^-2. GIVEN THIS...IT APPEARS THE THREAT
FOR LARGE HAIL...STRONG STRAIGHT-LINE WIND AND TORNADIC ACTIVITY
WILL INCREASE ACROSS PORTIONS OF OUR AREA AROUND OR AFTER
00Z...PRIMARILY SOUTH OF I-80.
PERSISTENT THERMAL ADVECTION ALONG THE AFOREMENTIONED LOW LEVEL
JET AXIS SHOULD THEN HELP MAINTAIN CONVECTION THROUGH MUCH OF THE
OVERNIGHT HOURS...WITH CONVECTION LIKELY CONGEALING INTO A LINEAR
MCS ACROSS OUR EAST/SOUTHEASTERN CWA BEFORE MARCHING EAST INTO THE
MISSOURI RIVER VALLEY AROUND SUNRISE SUNDAY. SO ALTHOUGH THE
TORNADIC THREAT SHOULD DIMINISH TOWARDS 03Z AS THE CONVECTION
BECOMES INCREASINGLY ELEVATED...THE THREAT FOR LARGE HAIL AND
STRONG STRAIGHT-LINE WIND COULD PERSIST THROUGH EARLY SUNDAY
MORNING UNTIL DEEP CONVECTION CLEARS OUR AREA TO THE EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 338 AM CDT SAT MAY 9 2015
ALOFT: THE WRN USA TROF WILL REMAIN LOCKED IN. LOW PRES WILL BE
OVER WRN NEB AT 12Z/SUN WITH THE DRY SLOT ALREADY OVER THE FCST
AREA. A TROF WILL LINGER INTO MON AS THIS LOW DEPARTS FOR THE UPR
MIDWEST. HEIGHTS WILL RISE TUE AS A SHORTWAVE RIDGE OVERTAKES THE
REGION. DEEP SW FLOW WILL DEVELOP WED AND THEN PERSIST FOR SEVERAL
DAYS THE WRN USA TROF RELOADS. EXPECT MULTIPLE LOW-AMPLITUDE
SHORTWAVE TROFS TO EJECT OUT OF THE MEAN TROF...MODULATING TSTM
POTENTIAL. THE LOW- AMPLITUDE NATURE RESULTS IN LOW PREDICTABILITY
AND CONFIDENCE THIS FAR OUT.
SURFACE: LOW PRES WILL BE CROSSING NEB SUN MORNING WITH A STRONG
COOL FRONT SWEEPING THRU THE REGION. THIS LOW WILL HEAD FOR THE
UPR MIDWEST SUN-MON. HIGH PRES FORMS AND EXPANDS OVER THE CNTRL
PLAINS MON INTO MON NIGHT. THIS HIGH WILL SHIFT E OF THE REGION
TUE WITH RETURN FLOW AND A NEW LEE-SIDE TROF DEVELOPING.
UNCERTAINTY INCREASES TUE THRU THE REST OF THE FCST. IT CURRENTLY
LOOKS LIKE A WARM FRONT WILL FORM AND LIFT N OF THE FCST AREA TUE
OR WED. THE STRONG FRONT THAT MOVES THRU SUN WILL BECOME
STATIONARY FROM THE GULF COAST INTO THE SRN PLAINS. THE TAIL END
OF THIS FRONT MAY ALSO LIFT N. BOTTOM LINE IS HIGH PRES WILL
DOMINATE THE ERN USA FOR SEVERAL DAYS WITH LOW PRES OVER THE W. SO
EXPECT GULF MOISTURE TO RETURN N WITH MULTIPLE CHANCES FOR TSTMS.
SOME DAILY DETAILS...
SUN: A CHANGEABLE DAY. THE MOST SUN WILL BE S AND E OF THE TRI-
CITIES. CAN`T RULE OUT A LITTLE LIGHT RAIN N AND W OF THE TRI-
CITIES ON THE SE FRINGE OF THE COMMAHEAD PRECIP SHIELD. BECOMING
WINDY. W WINDS WILL GUST 30-35 KTS.
HIGH TEMPS ARE TOUGH WITH DRY SLOT/COOL FRONTAL PASSAGE/CAA.
MON: A VERY COOL DAY IN THE COLD SECTOR. HIGHS WON`T GEN OUT OF
THE 50S OVER S-CNTRL NEB. A POTENT SHORTWAVE TROF BUT MODELS ARE
CURRENTLY NOT INDICATING ENOUGH MOISTURE TO PRODUCE SHWRS. THE
COLD AIR ALOFT AND DEEP MIXING WILL RESULT IN ANOTHER WINDY DAY.
NW WINDS GUST 30-35 KTS. LOTS OF STRATOCU...ESPECIALLY N OF HWY 6.
MON NIGHT: NEED TO WATCH FROST/FREEZE POTENTIAL...ESPECIALLY N
AND W OF THE TRI-CITIES. THE PLATTE RIVER VALLEY IN DAWSON COUNTY
AND THE N AND MIDDLE LOUP RIVER VALLEY`S WILL BE MOST SUSCEPTIBLE.
TUE: A NICE DAY WITH GOOD TEMP RECOVERY AND LIGHTER WINDS.
WED-FRI: UNCERTAINTY WITH NO SIGNIFICANT LOW PRES...BUT
DIFFERENTIAL ADVECTION WILL RESULT IN GULF MOISTURE AND THE
ELEVATED MIXED LAYER OVERTAKING THE AREA WED. SCT TSTMS WILL BE
PRIMARILY DRIVEN BY PULSES OF WAA/CONVERGENCE ASSOCIATED WITH THE
LOW-LVL JET AND/OR TSTMS THAT DEVELOP WITHIN THE LEE-SIDE TROF AND
MEANDER E INTO THE FCST AREA.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 546 AM CDT SAT MAY 9 2015
MVFR CONDITIONS EXPECTED DURING MUCH OF THE TAF PERIOD.
STRATUS...WITH A BASE IN THE 1000-2000FT AGL RANGE...PERSISTS
ACROSS THE REGION AS OF THIS WRITING...AND GUIDANCE SUGGESTS THIS
STRATUS WILL CONTINUE IMPACTING THE AREA THROUGH MUCH OF TODAY AND
INTO THIS EVENING. GIVEN THIS...WENT AHEAD WITH WITH A CEILING IN
THE 1500-2000FT AGL RANGE IN BOTH TAFS UNTIL 05Z. VFR CONDITIONS
ARE THEN FORECAST 05Z ONWARD. WEAK CONVECTION HAS DEVELOPED OVER
SOUTH-CENTRAL NEBRASKA...AND THIS ACTIVITY WILL BRING AT LEAST A
CHANCE FOR THUNDERSTORMS AND MEASURABLE PRECIPITATION AT BOTH TAF
SITES THROUGH 13Z. WENT AHEAD WITH VCTS THROUGH 13Z AS A RESULT.
ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY APPEARS LIKELY THIS
AFTERNOON INTO THIS EVENING AND AS A RESULT...WENT AHEAD WITH VCTS
21-05Z. THE SURFACE WIND WILL REMAIN FROM THE EAST/NORTHEAST
THROUGH TODAY...BEFORE BECOMING MORE SOUTHEASTERLY TONIGHT.
VISIBILITY RESTRICTION IS NOT CURRENTLY EXPECTED DURING THE TAF
PERIOD...ALTHOUGH IT IS WORTH MENTIONING THAT LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE THIS AFTERNOON INTO TONIGHT AND IF
REALIZED...COULD CERTAINLY PROMOTE PERIODIC VISIBILITY
RESTRICTION.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...BRYANT
LONG TERM...HALBLAUB
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
910 AM PDT SAT MAY 9 2015
.SYNOPSIS...LINGERING MOISTURE ON THE BACK SIDE OF A DEPARTING STORM
SYSTEM WILL RESULT IN SHOWERS AND A FEW THUNDERSTORMS AROUND THE
AREA TODAY AND TONIGHT ESPECIALLY ACROSS SOUTHERN NEVADA AND FAR
NORTHERN MOHAVE COUNTY. OTHERWISE EXPECT A WARMING TREND TO START
TODAY AND LAST THROUGH MONDAY. A DRY SYSTEM WILL CROSS THE AREA ON
TUESDAY BRINGING BREEZY CONDITIONS. ANOTHER SYSTEM MAY IMPACT THE
AREA ON THURSDAY WITH MORE WIND AND POSSIBLY RESULT IN A SHOWER IN
THE SOUTHERN SIERRA.
&&
.UPDATE...QUICK UPDATE THIS MORNING TO ADJUST POPS AND SKY COVER TO
ACCOUNT FOR THE BAND OF CLOUDS AND LIGHT SHOWERS CURRENTLY MOVING
SOUTHEAST OVER OVERTON TOWARD SOUTH COVE. THIS WILL WANE, YET STILL
EXPECT ADDITIONAL DEVELOPMENT LATER THIS AFTERNOON AND EARLY
EVENING. THE LAST FEW RUNS OF THE HRRR HAVE HAD A DECENT HANDLE ON
THE CURRENT CONDITIONS AND CONTINUE TO INDICATE REDEVELOPMENT LATER
THIS AFTERNOON. SHOULD SEE SHOWERS AND PERHAPS A FEW STORMS DEVELOP
ACROSS SOUTHERN NEVADA, WITH LESSER DEVELOPMENT EXPECTED FARTHER
WEST INTO INYO COUNTY. AS MENTIONED IN THE PREVIOUS DISCUSSION,
DEVELOPMENT ON THE SPRING MOUNTAINS AND SHEEP RANGE WOULD TEND TO
TRACK TOWARD THE LAS VEGAS VALLEY ON A GENERAL NORTHWEST STEERING
FLOW LATER THIS AFTERNOON AND EVENING. HAVE KEPT THIS CHANCE
MENTIONED GIVEN THE LATEST MODEL TRENDS. COULD ALSO EXPECT GUSTY
WINDS NEAR ANY ACTIVITY, SIMILAR TO YESTERDAY, FAVORING A NORTHWEST
COMPONENT.
&&
.AVIATION...FOR MCCARRAN...WINDS WILL GENERALLY TREND TOWARD TYPICAL
DIURNAL DIRECTIONS AT 4-8 KTS THROUGH THIS AFTERNOON. CLOUDS WILL
ADVANCE INTO THE VALLEY AND BECOME BKN AOA 6-8K FEET BY THIS
AFTERNOON. THERE IS THE POSSIBILITY THAT FEW SHRA OR EVEN A TSRA
COULD MOVE OFF THE SPRING MTS AND SHEEP RANGE INTO THE VALLEY THIS
EVENING, ESPECIALLY WEST AND NORTH OF KLAS. IF ANYTHING CROSSES THE
AIRPORT COMPLEX ITSELF THE MOST LIKELY TIME LOOKS TO BE BETWEEN 00Z
AND 03Z SUNDAY WHEN BASES COULD LOWER TO 5K-7K FEET AND WILL CARRY A
TEMPO GROUP FOR THIS. THIS WOULD ALSO FAVOR A WEST TO NORTHWEST
WIND. DEPENDING ON THE PROXIMITY OF THE SHOWERS, WINDS COULD BE
GUSTY. ONCE THIS LINE OF ENHANCED CLOUDS AND ANY SHRA PASS THROUGH
WINDS WOULD FAVOR A NORTHERLY (PERHAPS NORTHEAST) WIND AT 5-10 KTS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WINDS WILL MAINLY FOLLOW TYPICAL DIURNAL DIRECTIONAL
TRENDS AT 6-12 KTS WITH LOCAL GUSTS OF 15-20 KTS AT KDAG. NORTH
WINDS WILL INCREASE IN THE OWENS VALLEY THIS AFTERNOON AND EARLY
EVENING TO 15-22 KTS WITH GUSTS TO 30 KTS. SHRA AND ISOLATED TSRA
CAN BE EXPECTED ACROSS LINCOLN, ESMERALDA, CENTRAL NYE, CLARK, AND
NORTHERN MOHAVE COUNTIES TODAY. ISOLATED SHRA/TSRA WILL ALSO BE
AROUND IN THE HIGHER TERRAIN OF INYO COUNTY THROUGH THIS EVENING.
GUSTY AND ERRATIC WINDS ARE POSSIBLE NEAR ANY SHRA/TSRA. SCT-BKN
CLOUDS AOA 4K-8K FEET. WINDS WILL SHIFT TO THE WEST TO NORTHWEST AND
EVENTUALLY NORTH AT 5-10 KTS ACROSS MUCH OF THE AREA LATER TONIGHT.
&&
.PREVIOUS DISCUSSION...
311 AM PDT SAT MAY 9 2015
.SHORT TERM...TODAY THROUGH MONDAY NIGHT.
THE CENTER OF THE COLD MID/UPPER LEVEL LOW THAT MOVED ACROSS THE
AREA YESTERDAY WAS OVER THE CENTER OF NORTHERN ARIZONA EARLY THIS
MORNING NEAR FLAGSTAFF. THE BROAD CIRCULATION AROUND THIS LOW WILL
RESULT IN ENERGY AND MOISTURE (ESPECIALLY IN THE MID-LEVELS)
WRAPPING SOUTH TO SOUTHEAST ACROSS OUR AREA TODAY. THE LATEST
INFRARED SATELLITE SHOWS CLOUD TOPS HAVE COOLED ACROSS NORTHERN
LINCOLN COUNTY AS A BAND OF PRECIPITATION SPREADS SOUTH INTO THERE
FROM WHITE PINE COUNTY AND ADJACENT AREAS OF SOUTHWEST UTAH. LIGHT
RAIN WAS REPORTED AT ELY FROM THIS BAND AND GIVEN RADAR COVERAGE IN
THIS PART OF THE AREA IS NOT THE BEST TO BEGIN WITH AND WHATEVER THE
RADAR BEAMS CAN SEE IS BEING OVERSHOT, I WILL ASSUME MORE PLACES ARE
SEEING PRECIPITATION THAN NOT. THE HRRR SEEMS TO HAVE A GOOD HANDLE
ON THIS AREA AS DO THE OPERATIONAL RUNS OF THE ECMWF, WRF AND GFS
AND THE NMM AND ARW LOCAL MODELS. THUS I INCREASED POPS FOR LINCOLN
COUNTY THIS MORNING. THIS BAND OF PRECIPITATION SHOULD SPREAD SOUTH
TOWARD CLARK AND CENTRAL NYE COUNTIES BY LATER THIS MORNING. SNOW
LEVELS WILL BE AROUND 7000-7500 FEET IN THESE AREAS EARLY THIS
MORNING BUT RISE TO NEAR 9000 FEET BY THIS AFTERNOON AS WARMER AIR
STARTS TO WORK ON IN FROM THE WEST. SO ANY SNOW AMOUNTS WILL BE
LIGHT IN ANY AREAS ON THE UPPER FRINGES OF WHERE FOLKS LIVE AT.
LINGERING ENERGY AND MOISTURE WILL CONTINUE TO ROTATE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING AND WITH THE HEATING OF THE
DAY WE SHOULD SEE SHOWER ACTIVITY BECOME A LITTLE MORE EXTENSIVE
THIS AFTERNOON ESPECIALLY OVER THE HIGHER ELEVATIONS OF SOUTHERN
NEVADA AND INYO COUNTY. A FEW THUNDERSTORMS ARE POSSIBLE AS WELL.
FORECAST SOUNDINGS SHOW DRY LOW-LEVELS WITH AN INVERTED V LOOK SO
GUSTY WINDS WILL BE A CONCERN. FOR THE LAS VEGAS VALLEY, THE ARW AND
NMM AND HINTS OFF OPERATIONAL MODELS ARE THAT WE SHOULD SEE THINGS
CLOUD UP MORE BY LATE THIS MORNING AND AFTERNOON WITH THE POTENTIAL
FOR ANY SHOWERS OR THUNDERSTORMS THAT FORM OVER THE SPRING MTS AND
SHEEP RANGE TO MOVE INTO THE VALLEY LATE THIS AFTERNOON OR VERY
EARLY THIS EVENING ESPECIALLY ON THE WEST AND NORTH SIDES AS THE
STEERING FLOW PUSHES THEM IN. THUS I HAVE KEPT A SLIGHT CHANCE OF
ACTIVITY IN FOR THESE TIME PERIODS. TEMPS TODAY WILL BE MUCH WARMER
AREA-WIDE WITH THE COLD LOW HAVING DEPARTED WITH HIGHS A GOOD 12-18
DEGREES ABOVE NORMAL. SHOWERS MAY WORK INTO FAR NORTHERN MOHAVE
COUNTY BY THIS EVENING BUT MOST AREAS SHOULD SEE SHOWERS END BY
LATER THIS EVENING.
LINGERING ENERGY AND MOISTURE IN THE CYCLONIC FLOW AROUND THE
DEPARTING LOW MAY STILL BRING A FEW SHOWERS ON SUNDAY TO FAR EASTERN
LINCOLN AND FAR NORTHEAST MOHAVE COUNTIES. OTHERWISE, A SHORTWAVE
MID/UPPER LEVEL RIDGE AXIS BUILDS IN AND WILL ALLOW FOR FURTHER
WARMING WITH TEMPS CLIMBING TO OR JUST A FEW DEGREES BELOW NORMAL.
FURTHER WARMING WILL TAKE PLACE ON MONDAY AHEAD OF THE NEXT
MID/UPPER LEVEL TROUGH AXIS WHICH MOVES INTO NORCAL BY THE EVENING.
A SOUTHWEST FLOW ALOFT AND AT THE SURFACE BY THE AFTERNOON SHOULD
MIX THINGS UP GOOD AND RESULT IN HIGHS A FEW DEGREES ABOVE NORMAL. I
SIDED WITH THE WARMER END OF GUIDANCE. AFTER THE RECENT CHILL, THE
HIGHS OF 90 TO 100 IN THE LOWER ELEVATIONS OF THE MOJAVE DESERT MAY
FEEL A BIT TOASTY TO SOME. THE SPRING SWING WILL BE IN FULL FORCE.
GUSTS IN THE AFTERNOON AND EVENING OF 15-25 MPH ARE POSSIBLE
ESPECIALLY IN FAVORED SPOTS UNDER ADVANCING CIRRUS CLOUDS.
.LONG TERM...TUESDAY THROUGH FRIDAY.
BY TUESDAY MORNING MODELS AGREE ON THE EXISTENCE OF LOW PRESSURE
SOMEWHERE NORTHWEST OF OUR CWA...BUT ALREADY DISAGREE ON STRENGTH
AND PLACEMENT...SO CONFIDENCE IN THIS FORECAST IS BELOW AVERAGE.
MAIN CONCERN FOR TUESDAY APPEARS TO BE WIND SPEED. FORECAST REFLECTS
BREEZY CONDITIONS BUT WELL BELOW WIND ADVISORY LEVEL...BUT IF MODELS
TREND TOWARD THE OPERATIONAL ECMWF WINDS COULD BE STRONGER.
WEDNESDAY LOOKS LIKE SOME FLAVOR OF DRY SOUTHWEST FLOW AS THE NEXT
LOW PRESSURE SYSTEM CONSOLIDATES OFF THE WEST COAST. BY THURSDAY
THIS LOW DRAWS NEAR ENOUGH TO JUSTIFY PRECIP CHANCES IN THE
SIERRA...AND THEN SPREADING ACROSS THE HIGHER TERRAIN MAINLY NEAR
AND NORTH OF LAS VEGAS ON FRIDAY AS THE LOW SWINGS INLAND.
TEMPERATURES START OFF SLIGHTLY ABOVE NORMAL TUESDAY...DROP TO NEAR
NORMAL WEDNESDAY AND THURSDAY...THEN BELOW NORMAL FRIDAY AS THE LOW
MOVES IN.
&&
.SPOTTER INFORMATION STATEMENT....SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...PADDOCK
SHORT TERM...STACHELSKI
LONG TERM...MORGAN
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
311 AM PDT SAT MAY 9 2015
.SYNOPSIS...LINGERING MOISTURE ON THE BACK SIDE OF A DEPARTING STORM
SYSTEM WILL RESULT IN SHOWERS AND A FEW THUNDERSTORMS AROUND THE
AREA TODAY AND TONIGHT ESPECIALLY ACROSS SOUTHERN NEVADA AND FAR
NORTHERN MOHAVE COUNTY. OTHERWISE EXPECT A WARMING TREND TO START
TODAY AND LAST THROUGH MONDAY. A DRY SYSTEM WILL CROSS THE AREA ON
TUESDAY BRINGING BREEZY CONDITIONS. ANOTHER SYSTEM MAY IMPACT THE
AREA ON THURSDAY WITH MORE WIND AND POSSIBLY RESULT IN A SHOWER IN
THE SOUTHERN SIERRA.
&&
.SHORT TERM...TODAY THROUGH MONDAY NIGHT.
THE CENTER OF THE COLD MID/UPPER LEVEL LOW THAT MOVED ACROSS THE
AREA YESTERDAY WAS OVER THE CENTER OF NORTHERN ARIZONA EARLY THIS
MORNING NEAR FLAGSTAFF. THE BROAD CIRCULATION AROUND THIS LOW WILL
RESULT IN ENERGY AND MOISTURE (ESPECIALLY IN THE MID-LEVELS)
WRAPPING SOUTH TO SOUTHEAST ACROSS OUR AREA TODAY. THE LATEST
INFRARED SATELLITE SHOWS CLOUD TOPS HAVE COOLED ACROSS NORTHERN
LINCOLN COUNTY AS A BAND OF PRECIPITATION SPREADS SOUTH INTO THERE
FROM WHITE PINE COUNTY AND ADJACENT AREAS OF SOUTHWEST UTAH. LIGHT
RAIN WAS REPORTED AT ELY FROM THIS BAND AND GIVEN RADAR COVERAGE IN
THIS PART OF THE AREA IS NOT THE BEST TO BEGIN WITH AND WHATEVER THE
RADAR BEAMS CAN SEE IS BEING OVERSHOT, I WILL ASSUME MORE PLACES ARE
SEEING PRECIPITATION THAN NOT. THE HRRR SEEMS TO HAVE A GOOD HANDLE
ON THIS AREA AS DO THE OPERATIONAL RUNS OF THE ECMWF, WRF AND GFS
AND THE NMM AND ARW LOCAL MODELS. THUS I INCREASED POPS FOR LINCOLN
COUNTY THIS MORNING. THIS BAND OF PRECIPITATION SHOULD SPREAD SOUTH
TOWARD CLARK AND CENTRAL NYE COUNTIES BY LATER THIS MORNING. SNOW
LEVELS WILL BE AROUND 7000-7500 FEET IN THESE AREAS EARLY THIS
MORNING BUT RISE TO NEAR 9000 FEET BY THIS AFTERNOON AS WARMER AIR
STARTS TO WORK ON IN FROM THE WEST. SO ANY SNOW AMOUNTS WILL BE
LIGHT IN ANY AREAS ON THE UPPER FRINGES OF WHERE FOLKS LIVE AT.
LINGERING ENERGY AND MOISTURE WILL CONTINUE TO ROTATE ACROSS THE
AREA THIS AFTERNOON INTO THIS EVENING AND WITH THE HEATING OF THE
DAY WE SHOULD SEE SHOWER ACTIVITY BECOME A LITTLE MORE EXTENSIVE
THIS AFTERNOON ESPECIALLY OVER THE HIGHER ELEVATIONS OF SOUTHERN
NEVADA AND INYO COUNTY. A FEW THUNDERSTORMS ARE POSSIBLE AS WELL.
FORECAST SOUNDINGS SHOW DRY LOW-LEVELS WITH AN INVERTED V LOOK SO
GUSTY WINDS WILL BE A CONCERN. FOR THE LAS VEGAS VALLEY, THE ARW AND
NMM AND HINTS OFF OPERATIONAL MODELS ARE THAT WE SHOULD SEE THINGS
CLOUD UP MORE BY LATE THIS MORNING AND AFTERNOON WITH THE POTENTIAL
FOR ANY SHOWERS OR THUNDERSTORMS THAT FORM OVER THE SPRING MTS AND
SHEEP RANGE TO MOVE INTO THE VALLEY LATE THIS AFTERNOON OR VERY
EARLY THIS EVENING ESPECIALLY ON THE WEST AND NORTH SIDES AS THE
STEERING FLOW PUSHES THEM IN. THUS I HAVE KEPT A SLIGHT CHANCE OF
ACTIVITY IN FOR THESE TIME PERIODS. TEMPS TODAY WILL BE MUCH WARMER
AREA-WIDE WITH THE COLD LOW HAVING DEPARTED WITH HIGHS A GOOD 12-18
DEGREES ABOVE NORMAL. SHOWERS MAY WORK INTO FAR NORTHERN MOHAVE
COUNTY BY THIS EVENING BUT MOST AREAS SHOULD SEE SHOWERS END BY
LATER THIS EVENING.
LINGERING ENERGY AND MOISTURE IN THE CYCLONIC FLOW AROUND THE
DEPARTING LOW MAY STILL BRING A FEW SHOWERS ON SUNDAY TO FAR EASTERN
LINCOLN AND FAR NORTHEAST MOHAVE COUNTIES. OTHERWISE, A SHORTWAVE
MID/UPPER LEVEL RIDGE AXIS BUILDS IN AND WILL ALLOW FOR FURTHER
WARMING WITH TEMPS CLIMBING TO OR JUST A FEW DEGREES BELOW NORMAL.
FURTHER WARMING WILL TAKE PLACE ON MONDAY AHEAD OF THE NEXT
MID/UPPER LEVEL TROUGH AXIS WHICH MOVES INTO NORCAL BY THE EVENING.
A SOUTHWEST FLOW ALOFT AND AT THE SURFACE BY THE AFTERNOON SHOULD
MIX THINGS UP GOOD AND RESULT IN HIGHS A FEW DEGREES ABOVE NORMAL. I
SIDED WITH THE WARMER END OF GUIDANCE. AFTER THE RECENT CHILL, THE
HIGHS OF 90 TO 100 IN THE LOWER ELEVATIONS OF THE MOJAVE DESERT MAY
FEEL A BIT TOASTY TO SOME. THE SPRING SWING WILL BE IN FULL FORCE.
GUSTS IN THE AFTERNOON AND EVENING OF 15-25 MPH ARE POSSIBLE
ESPECIALLY IN FAVORED SPOTS UNDER ADVANCING CIRRUS CLOUDS.
.LONG TERM...TUESDAY THROUGH FRIDAY.
BY TUESDAY MORNING MODELS AGREE ON THE EXISTENCE OF LOW PRESSURE
SOMEWHERE NORTHWEST OF OUR CWA...BUT ALREADY DISAGREE ON STRENGTH
AND PLACEMENT...SO CONFIDENCE IN THIS FORECAST IS BELOW AVERAGE.
MAIN CONCERN FOR TUESDAY APPEARS TO BE WIND SPEED. FORECAST REFLECTS
BREEZY CONDITIONS BUT WELL BELOW WIND ADVISORY LEVEL...BUT IF MODELS
TREND TOWARD THE OPERATIONAL ECMWF WINDS COULD BE STRONGER.
WEDNESDAY LOOKS LIKE SOME FLAVOR OF DRY SOUTHWEST FLOW AS THE NEXT
LOW PRESSURE SYSTEM CONSOLIDATES OFF THE WEST COAST. BY THURSDAY
THIS LOW DRAWS NEAR ENOUGH TO JUSTIFY PRECIP CHANCES IN THE
SIERRA...AND THEN SPREADING ACROSS THE HIGHER TERRAIN MAINLY NEAR
AND NORTH OF LAS VEGAS ON FRIDAY AS THE LOW SWINGS INLAND.
TEMPERATURES START OFF SLIGHTLY ABOVE NORMAL TUESDAY...DROP TO NEAR
NORMAL WEDNESDAY AND THURSDAY...THEN BELOW NORMAL FRIDAY AS THE LOW
MOVES IN.
&&
.AVIATION...FOR MCCARRAN...WINDS WILL GENERALLY TREND TOWARD TYPICAL
DIURNAL DIRECTIONS AT 4-8 KTS THROUGH THIS AFTERNOON. CLOUDS WILL
ADVANCE INTO THE VALLEY AND BECOME BKN AOA 6-8K FEET BY THIS
AFTERNOON. THERE IS THE POSSIBILITY THAT FEW SHRA OR EVEN A TSRA
COULD MOVE OFF THE SPRING MTS AND SHEEP RANGE INTO THE VALLEY THIS
EVENING...ESPECIALLY WEST AND NORTH OF KLAS. IF ANYTHING CROSSES THE
AIRPORT COMPLEX ITSELF THE MOST LIKELY TIME LOOKS TO BE BETWEEN 00Z
AND 03Z SUNDAY WHEN BASES COULD LOWER TO 5K-7K FEET AND WILL CARRY A
TEMPO GROUP FOR THIS. ONCE THIS LINE OF ENHANCED CLOUDS AND ANY SHRA
PASS THROUGH WINDS SHOULD TURN MORE TO THE SOUTHWEST OR WEST AND
EVENTUALLY NORTHWEST AT 5-10 KTS. CLOUDS WILL SLOWLY DECREASE LATER
THIS EVENING AS NORTHWEST TO NORTH WINDS PREVAIL AT 5-10 KTS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WINDS WILL MAINLY FOLLOW TYPICAL DIURNAL DIRECTIONAL
TRENDS AT 6-12 KTS WITH LOCAL GUSTS OF 15-20 KTS AT KDAG. NORTH
WINDS WILL INCREASE IN THE OWENS VALLEY THIS AFTERNOON AND EARLY
EVENING TO 15-22 KTS WITH GUSTS TO 30 KTS. SHRA AND ISOLATED TSRA
WILL BE AROUND MAINLY ACROSS LINCOLN, ESMERALDA AND CENTRAL NYE
COUNTIES THIS MORNING THEN SPREAD INTO CLARK AND FAR NORTHERN MOHAVE
COUNTIES BY LATE THIS MORNING INTO EARLY THIS EVENING. ISOLATED
SHRA/TSRA WILL ALSO BE AROUND IN THE HIGHER TERRAIN OF INYO COUNTY
THROUGH THIS EVENING. GUSTY AND ERRATIC WINDS ARE POSSIBLE NEAR ANY
SHRA/TSRA. SCT-BKN CLOUDS AOA 4K-8K FEET. WINDS WILL SHIFT TO THE
WEST TO NORTHWEST AND EVENTUALLY NORTH AT 5-10 KTS ACROSS MUCH OF
THE AREA LATER TONIGHT.
&&
.SPOTTER INFORMATION STATEMENT....SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...STACHELSKI
LONG TERM...MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BUFFALO NY
937 PM EDT SUN MAY 10 2015
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL REMAIN NEAR THE AREA TONIGHT THROUGH
MONDAY NIGHT AND ACT AS A PATHWAY FOR SEVERAL ROUNDS OF SHOWERS AND
THUNDERSTORMS. THE FRONT WILL FINALLY SWEEP THROUGH THE AREA TUESDAY
AND BRING AN END TO MOST OF THE RAIN...ALTHOUGH A FEW BRIEF LIGHT
SHOWERS WILL STILL BE POSSIBLE THROUGH WEDNESDAY. WARM AND HUMID
WEATHER WILL PERSIST INTO MONDAY BEFORE DRAMATICALLY COOLER AIR
ARRIVES BEHIND THE FRONT BY MIDWEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
OUR ATTENTION TURNS TO A MORE WELL DEFINED MID LEVEL SHORTWAVE SEEN
IN WATER VAPOR IMAGERY AND OBJECTIVE RUC ANALYSIS OVER WESTERN OHIO
AND WESTERN LAKE ERIE. CONVECTION IS EXPANDING IN THE LARGE SCALE
ASCENT AHEAD OF THIS FEATURE...AND WILL SPREAD NORTHEASTWARD ACROSS
LAKE ERIE THROUGH THE EVENING. THERE IS THE EXPECTED SPREAD IN
DEALING WITH THIS CONVECTION IN VARIOUS MODEL GUIDANCE...BUT A
DECENT SIGNAL EXISTS IN THE 00Z/10 SSEO MESOSCALE ENSEMBLE DATA AND
THE NEWER 12Z WRF-ARW AND TO SOME EXTENT THE OPERATIONAL NAM/GFS
RUNS. FOLLOWING A MESOSCALE MODEL CONSENSUS EXPECT AN AREA OF
CONVECTION TO REACH WESTERN NY DURING THE MID TO LATE EVENING...THEN
SPREAD NORTHEASTWARD ACROSS LAKE ONTARIO AND INTO THE NORTH COUNTRY
LATE TONIGHT. AT THE SAME TIME...A LOW LEVEL BOUNDARY WILL SINK
SOUTH INTO THE AREA WITH SURFACE WINDS BECOMING NORTH TO NORTHEAST.
THIS DIFFERENTIAL TEMPERATURE ADVECTION REGIME WILL ENHANCE
ISENTROPIC UPGLIDE ACROSS THE BOUNDARY AND SUPPORT SOMEWHAT MORE
WIDESPREAD SHOWERS AND EMBEDDED CONVECTION AS THE SHORTWAVE MOVES
NORTHEAST ACROSS THE AREA.
PWAT VALUES REMAIN AT 1.5 INCHES OR HIGHER OVERNIGHT...SO ANY OF THE
STRONGER CONVECTION WILL PRODUCE LOCALLY HEAVY RAINFALL. DRY
ANTECEDENT CONDITIONS AND PROGRESSIVE STORM MOTION SHOULD PRECLUDE
ANY FLOODING CONCERNS. SEVERE WEATHER POTENTIAL REMAINS MINIMAL
GIVEN THE WEAK SHEAR...MARGINAL INSTABILITY...AND POOR DIURNAL
TIMING.
IT WILL REMAIN VERY WARM AND HUMID OVERNIGHT WITH LOWS ONLY IN THE
MID TO UPPER 60S ON THE LAKE PLAINS AND LOWER 60S ACROSS THE
SOUTHERN TIER VALLEYS. THE NORTH COUNTRY WILL DROP INTO THE UPPER
50S BEHIND THE WEAK FRONTAL BOUNDARY.
MONDAY MORNING EXPECT A RELATIVE LULL IN RAIN COVERAGE...ALTHOUGH A
FEW PASSING LIGHT SHOWERS CANNOT BE RULED OUT WITH THE WEAK LOW
LEVEL FRONTAL ZONE DRAPED OVER THE AREA. CONVECTION WILL BREAK OUT
AGAIN DURING THE AFTERNOON WITH DIURNAL DESTABILIZATION. EXPECT THE
BULK OF THE CONVECTION TO INITIALLY ASSOCIATE WITH THE LAKE BREEZE
BOUNDARIES...THEN SPREAD INLAND ACROSS THE GENESEE VALLEY...FINGER
LAKES...AND CENTRAL NY DURING THE MID TO LATE AFTERNOON. RAIN
COVERAGE SHOULD BE LOWEST NORTHEAST OF LAKES ERIE AND ONTARIO
INCLUDING BUFFALO AND WATERTOWN AS LAKE SHADOWS ATTEMPT TO FORM...
ALTHOUGH WITH SOME SYNOPTIC SCALE ASCENT IT MAY NOT REMAIN
COMPLETELY DRY IN THE LAKE SHADOWS.
PWAT VALUES REMAIN GREATER THAN 1.5 INCHES...SO AGAIN ANY STORMS MAY
PRODUCE LOCALLY HEAVY RAINFALL. MOST OF THE STORMS WILL REMAIN
PROGRESSIVE ENOUGH TO KEEP ANY FLOODING RISK LOW...ALTHOUGH IF
TRAINING DEVELOPS ALONG LAKE BREEZE BOUNDARIES SOME LOCAL FLOOD RISK
MAY DEVELOP. SEVERE WEATHER POTENTIAL REMAINS LOW...WITH RELATIVELY
WEAK INSTABILITY FEATURING TALL/SKINNY CAPE MORE FAVORABLE FOR HEAVY
RAIN. SHEAR REMAINS RELATIVELY WEAK AS WELL WITH MAX WIND SPEEDS OF
ONLY AROUND 30 KNOTS IN THE LOWEST 20K FEET OF THE COLUMN.
PERIODS OF CLOUD COVER MIXED WITH BREAKS OF SUN SHOULD ALLOW HIGHS
TO REACH THE LOWER 80S IN MOST AREAS MONDAY...WITH ONSHORE FLOW
KEEPING THE LAKESHORES MUCH COOLER. THE NORTH COUNTRY WILL REMAIN
NORTH OF THE STALLED FRONTAL BOUNDARY...WITH TEMPS ONLY IN THE 60S
NEAR THE SAINT LAWRENCE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
NO MAJOR CHANGES TO THE FORECAST PACKAGE ON THE EVENING UPDATE.
PREVIOUS DISCO BELOW...
AFTER SEVERAL DAYS OF ABOVE NORMAL TEMPERATURES AND HUMIDITY WE WILL
SEE A SHARP TURN TO COOLER AND DRIER WEATHER AS AN ARCTIC COLD FRONT
SHIFTS EAST ACROSS WESTERN AND CENTRAL NEW YORK. LOW PRESSURE WILL
BE CENTERED EARLY MONDAY EVENING OVER NORTHERN WISCONSIN WITH THE
FRONT DROPPING SOUTH ACROSS MICHIGAN. STORMS WILL SHIFT EAST ACROSS
LAKE ERIE THEN WESTERN NEW YORK ALONG A PRE-FRONTAL TROUGH AND
50KNOT LOW LEVEL JET. THE ACTUAL FRONT APPEARS TO BE DELAYED BEHIND
THE STORMS BY A FEW HOURS. FORECAST CAPE AND SHEAR VALUES APPEAR TOO
LOW FOR ANY SEVERE THREAT BUT GUSTY WINDS FROM THE LLJ MAY BE PULLED
DOWN BY THE SHOWERS. PWATS AROUND 1.5 INCHES WHICH IS NEAR CLIMO MAX
FOR MID MAY WILL ALSO BRING A THREAT OF HEAVY RAIN WITH THE STORMS.
TEMPERATURES WILL ONLY SLIDE BACK TO AROUND 60 MONDAY NIGHT.
THE TURN TO COLDER WEATHER COMES TUESDAY AS THE ARCTIC FRONT SLIDES
EAST ACROSS THE REGION. 850MB TEMPS WILL SLIDE BACK TO NEAR 0C BY
TUESDAY EVENING AS THE 500MB TROUGH SHIFTS OVER THE LOWER GREAT
LAKES. SURFACE TEMPS NEAR 60F TO START THE DAY WILL DROP TO 50F BY
EVENING THEN 40F TUESDAY NIGHT. THE COOLING TEMPERATURES AND DRIER
AIR ALOFT BEHIND THE FRONT WILL STEEPEN LOW LEVEL LAPSE RATES
ALLOWING GUSTS FROM A 50KT 850MB JET TO MIX TO THE SURFACE.
SUSTAINED WINDS OF 20-30 WITH GUSTS 30-40 WILL BE POSSIBLE.
SCATTERED INSTABILITY SHOWERS MAY ALSO POP UP BEHIND THE FRONT
TUESDAY AND TUESDAY NIGHT.
WEDNESDAY AND WEDNESDAY NIGHT EXPANSIVE ARCTIC SOURCED HIGH PRESSURE
WILL BUILD EAST ACROSS THE GREAT LAKES WITH A NORTH WEST FLOW OF DRY
MODIFIED-ARCTIC AIR CONTINUING TO WORK ACROSS THE FORECAST AREA.
850MB TEMPS OF 0C WHICH IS ABOUT 6 DEGREES BELOW NORMAL WILL KEEP
HIGHS STRUGGLING TO REACH INTO THE 50S DESPITE THE STRONG MAY SUN.
WINDS SHOULD SLACKEN WITH ANOTHER CHANCE OF INLAND DIURNAL SHOWERS
IF ENOUGH SYNOPTIC MOISTURE REMAINS. TEMPERATURES WEDNESDAY NIGHT
WILL SLIP INTO THE 30S AND LOW 40S SO FROST MAY BECOME A CONCERN
WITH CLEAR SKIES AND LIGHT WINDS. THIS HAS BEEN HIGHLIGHTED IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE SURFACE HIGH CENTERS OVERHEAD ON THURSDAY WITH ANOTHER COOL DAY
EXPECTED THEN SHIFTS TO THE EAST COAST FRIDAY WITH A SOUTHERLY FLOW
WARMING TEMPERATURES BACK TOWARD NORMAL. ADVECTION OF EVEN WARMER
AND MORE MOIST AIR NEXT WEEKEND BRINGS BACK CHANCES OF SHOWERS LATER
FRIDAY INTO SATURDAY AS GLOBAL MODELS FORECAST A WAVE OF LOW
PRESSURE AND 500MB SHORTWAVE CUTTING EAST ACROSS PENNSYLVANIA.
TEMPERATURES THEN LOOK TO RISE ABOVE NORMAL BY NEXT SUNDAY AS THE
12Z GFS AND ECMWF BOTH SHOW EAST COAST 500MB RIDGING DEVELOPING
AGAIN
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
WHILE MAINLY VFR CONDITIONS WILL PREVAIL OVERNIGHT...THERE WILL BE A
COUPLE BATCHES OF SHOWERS AND THUNDERSTORMS THAT WILL WORK ACROSS
THE AREA FROM SOUTHWEST TO NORTHEAST OVERNIGHT. IN THE HEAVIEST
SHOWERS/THUNDERSTORMS CIGS/VIS COULD BECOME LIMITED TO MVFR/IFR
CONDITIONS...HOWEVER THESE REDUCTIONS WILL BE FAIRLY SHORT LIVED
WITH THE TRANSIENT/SCATTERED NATURE OF THE SHOWERS/THUNDERSTORMS.
THE ONE EXCEPTION TO THE WIDELY VFR CONDITIONS WILL BE LATE TONIGHT
AND MONDAY MORNING ACROSS THE SAINT LAWRENCE VALLEY...INCLUDING
KART. A COLD FRONT OVER SOUTHERN ONTARIO WILL SAG SOUTHWARD...WITH
AREAS OF LOW MVFR CIGS DEVELOPING BEHIND IT.
ON MONDAY EXPECT A RELATIVE LULL IN CONVECTION DURING THE MORNING...
ALTHOUGH A FEW PASSING LIGHT SHOWERS CANNOT BE RULED OUT. EXPECT
MORE CONVECTION DURING THE AFTERNOON WITH THE BULK OF IT FORMING
ALONG AND INLAND OF THE LAKE BREEZE BOUNDARIES. THESE STORMS WILL
PRODUCE AREAS OF BRIEF MVFR/IFR SIMILAR TO TODAY...WITH MAINLY VFR
BETWEEN THE MORE ORGANIZED AREAS OF CONVECTION.
OUTLOOK...
MONDAY NIGHT...VFR WITH BRIEF MVFR/IFR IN SCATTERED SHOWERS AND
THUNDERSTORMS.
TUESDAY AND WEDNESDAY...MAINLY VFR WITH A CHANCE OF A SHOWER.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
WINDS WILL REMAIN RELATIVELY LIGHT INTO MONDAY ON BOTH LAKES AS A
WARM AIRMASS AND RELATIVELY WEAK PRESSURE GRADIENT REMAINS IN PLACE.
ANY SCATTERED THUNDERSTORMS WHICH CROSS THE AREA WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY GUSTY WINDS AND HIGHER WAVES.
A COLD FRONT WILL CROSS THE AREA LATE MONDAY NIGHT AND TUESDAY.
BEHIND THIS FRONT MUCH COOLER AIR WILL SURGE INTO THE LOWER LAKES
WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS POSSIBLE TUESDAY
THROUGH WEDNESDAY AS WINDS INCREASE ALONG AND BEHIND THE COLD FRONT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...CHURCH/HITCHCOCK
SHORT TERM...SMITH/THOMAS
LONG TERM...SMITH
AVIATION...CHURCH/HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
844 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE FOR THE NEXT COUPLE OF
DAYS ACROSS CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TOMORROW. A
STORM SYSTEM WILL MOVE THROUGH THE AREA WEDNESDAY BRINGING THE
CHANCE FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ALONG WITH
AND COOLER AIR.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
845 PM UPDATE...
FRONT CONTINUES TO HANG ACROSS NORTHERN AND WESTERN NY, WITH
SHOWERS AND EMBEDDED THUNDER SLIDING NORTHEASTWARD FROM THE
CENTRAL SO TIER TO THE WESTERN MOHAWK VALLEY. NAM12 TRIES TO BREAK
THIS ACTIVITY UP OVER THE NEXT 1-2 HOURS. HOWEVER THE HRRR KEEPS
THE ACTIVITY GOING THROUGH 8Z OR SO, AND AS OF NOW THE HRRR PROG
LOOKS TO BE HANDLING THE SITUATION BETTER.
INCREASED POPS FOR THE OVERNIGHT ALONG THE PRECIP STREAM.
245 PM EDT UPDATE... THE BACKDOOR FRONT DID MAKE IT INTO CENTRAL
NY TODAY AND IS NOW STATIONARY ALONG CENTRAL NY. BELIEVE THIS IS
AS FAR SOUTH AS IT WILL MOVE THIS AFTERNOON AS 2HR SFC PRESSURE
CHANGES ARE VERY WEAK AND SYNOPTICALLY THERE ISN`T MUCH IN THE WAY
OF FORCING TO PUSH IT FURTHER SOUTH. CONVECTION IS CURRENTLY ON-
GOING ALONG THIS BOUNDARY AND IT APPEARS THAT THEY ARE LOOSELY
DEVELOPED THUNDERSTORMS... IN THE SENSE OF 0-6 KM BULK SHEAR IS
NOT IMPRESSIVE AND THESE OUT DOWNDRAFT DOMINANT. THESE SHOWERS MAY
PRODUCE SOME GUSTY WINDS AND AT BEST SMALL NON-SEVERE SIZE HAIL
ALONG WITH BRIEF HEAVY RAINFALL. FREQUENT LIGHTNING MAY BE
POSSIBLE WITH THESE SHOWERS.
EXPECT COVERAGE OF THE SHOWERS TO INCREASE THIS AFTERNOON AS
INSTABILITY WILL INCREASE. THESE STORMS WILL MOVE TO THE NE
AROUND 20-25 MPH. THE INTENSITY OF THESE STORMS WILL WEAKEN AFTER
SUNSET AS SHOWERS ALONG THE FRONT ARE DIURNALLY DRIVEN. SOME
ISOLATED SHOWERS MAY LINGER AS WEAK INSTABILITY WILL STILL LINGER
THRU THE OVERNIGHT. THIS FRONT WILL LIFT NORTHWARD TONIGHT AND
TRANSITION INTO A PSEUDO-WARM FRONT.
TEMPS THIS AFTERNOON WILL AGAIN BE WELL ABOVE THE SEASONAL NORM.
TEMPS WILL RISE INTO THE 80S... AND MAYBE PEAK INTO THE 90S. TEMPS
ARE EXPECTED TO FALL INTO THE LOWER 60S BY SUNRISE ON MONDAY.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH WEDNESDAY/...
330 PM EDT UPDATE...
MONDAY AFTERNOON WILL BECOME UNSTABLE AGAIN AS WE REMAIN WITHIN
THE WARM SECTOR AND PLENTY OF MOISTURE WILL BE PRESENT. TEMPS
WILL REACH THE LOW 80S RESULTING IN ANOTHER UNUSUALLY WARM DAY. A
POTENT UPPR LVL TROUGH WILL MOVE INTO THE GREAT LAKES REGION
MONDAY AND PUSH A SFC LOW PRESSURE SYSTEM ACROSS THE MIDWEST.
THIS SFC LOW WILL EVENTUALLY DRAG A COLD FRONT OVER THE REGION BY
MID WEEK.
SCATTERED SHOWERS ARE EXPECTED TO DEVELOP QUICKLY LATE MONDAY MORNING
ACROSS MUCH OF THE AREA. THERE MAY BE A SLIGHT LULL IN ACTIVITY
MONDAY EVENING BEFORE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
MOVES INTO THE CWA AHEAD OF AN APPROACHING COLD FRONT.THE COLD
FRONT IS EXPECTED TO MOVE THROUGH THE AREA TUESDAY MORNING. WINDS
WILL BE BREEZY BEHIND THE FROPA. SHOWERS AND THUNDERSTORMS MAY
LINGER THRU WED AFTERNOON. ENVIRONMENTAL CONDITIONS DO NOT LOOK
FAVORABLE TO SEVERE WITH ALONG THE COLD FRONT.
THE FRONT WILL BRING A COLDER AIRMASS OVER THE REGION. THIS WILL
RESULT IN TEMPS SLOWLY FALLING DURING THE AFTERNOON. TEMPS WILL
FALL INTO THE LOW TO MID 40S BY WED MORNING. DUE TO THE MUCH
COOLER AIRMASS TEMPS ARE ONLY EXPECTED TO RISE INTO THE 50S ACROSS
MUCH OF THE AREA WED AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
430 PM UPDATE...
FAIRLY QUIET OVERALL WITH HIGH PRESSURE BUILDING IN WEDNESDAY
NIGHT AND IN CHARGE TO FRIDAY. PATCHY FROST A POSSIBILITY IN OUR
MORE PRONE COLD SPOTS WEDNESDAY NIGHT IF WINDS DECOUPLE FAST
ENOUGH FOR A PERIOD OF GOOD RADIATIONAL COOLING. TO A LESSER
DEGREE...THURSDAY NIGHT AS WELL IF HIGH THIN CLOUDS DO NOT SPREAD
IN ON TIME AHEAD OF NEXT WAVE. THIS WAVE TRANSLATES THROUGH
ROUGHLY ZONAL FLOW...WHICH BRING A BATCH OF SHOWERS LATE FRIDAY
NIGHT INTO SATURDAY /BETTER FOCUS IS TO OUR SOUTH/. AFTER COOL
TEMPERATURES THROUGH LATE WEEK...TEMPERATURES WILL TREND BACK TO
NORMAL OR EVEN SLIGHTLY ABOVE BY LATE IN THE WEEKEND.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
00Z MON UPDATE... PERSISTENT SHWRS/EMBEDDED TSTMS THIS EVE OVER
PTNS OF CNY...WILL LEAD TO A PD OF RESTRICTIVE CONDS AT OUR NY
TERMINAL SITES (KRME/KSYR/KITH HAVE THE BEST CHC AT PERIODIC
IFR/BLO ALT MIN VSBY`S).
LTR TNT...ALTHOUGH SHWRS/TSTMS SHOULD DIMINISH...THE COMBINATION
OF MOIST LOW-LVL CONDS AND LGT FLOW ARE EXPECTED TO LEAD TO LWR
CLD DEVELOPMENT/PATCHY FOG AFTER 06-08Z (KBGM/KITH HAVE THE BEST
CHC AT IFR/BLO ALT MIN CONDS).
ON MON...VFR SHOULD PREVAIL MUCH OF THE DAY...AS LWR EARLY MRNG
CLDS TRANSITION TO A BKN CU FIELD (CIG BASES OF 3500-4500 FT AGL).
LATE IN THE DAY (MAINLY AFTER 20Z)...SHWRS/TSTMS ARE EXPECTED TO
RE-DVLP...SO A PROB30 GROUP WAS INSERTED AT THIS JUNCTURE.
LGT SFC WINDS OVERNIGHT (AOB 5 KT)...SHOULD BECOME SWLY AT ARND 10
KT MON.
.OUTLOOK...
MON NGT INTO TUE...RESTRICTIONS ARE POSSIBLE IN SHWRS/TSTMS.
WED-FRI...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KAH
NEAR TERM...DJP/KAH
SHORT TERM...KAH
LONG TERM...MDP
AVIATION...MLJ/MDP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
815 PM EDT SUN MAY 10 2015
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL REMAIN NEAR THE AREA TONIGHT THROUGH
MONDAY NIGHT AND ACT AS A PATHWAY FOR SEVERAL ROUNDS OF SHOWERS AND
THUNDERSTORMS. THE FRONT WILL FINALLY SWEEP THROUGH THE AREA TUESDAY
AND BRING AN END TO MOST OF THE RAIN...ALTHOUGH A FEW BRIEF LIGHT
SHOWERS WILL STILL BE POSSIBLE THROUGH WEDNESDAY. WARM AND HUMID
WEATHER WILL PERSIST INTO MONDAY BEFORE DRAMATICALLY COOLER AIR
ARRIVES BEHIND THE FRONT BY MIDWEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
OUR ATTENTION TURNS TO A MORE WELL DEFINED MID LEVEL SHORTWAVE SEEN
IN WATER VAPOR IMAGERY AND OBJECTIVE RUC ANALYSIS OVER WESTERN OHIO
AND WESTERN LAKE ERIE. CONVECTION IS EXPANDING IN THE LARGE SCALE
ASCENT AHEAD OF THIS FEATURE...AND WILL SPREAD NORTHEASTWARD ACROSS
LAKE ERIE THROUGH THE EVENING. THERE IS THE EXPECTED SPREAD IN
DEALING WITH THIS CONVECTION IN VARIOUS MODEL GUIDANCE...BUT A
DECENT SIGNAL EXISTS IN THE 00Z/10 SSEO MESOSCALE ENSEMBLE DATA AND
THE NEWER 12Z WRF-ARW AND TO SOME EXTENT THE OPERATIONAL NAM/GFS
RUNS. FOLLOWING A MESOSCALE MODEL CONSENSUS EXPECT AN AREA OF
CONVECTION TO REACH WESTERN NY DURING THE MID TO LATE EVENING...THEN
SPREAD NORTHEASTWARD ACROSS LAKE ONTARIO AND INTO THE NORTH COUNTRY
LATE TONIGHT. AT THE SAME TIME...A LOW LEVEL BOUNDARY WILL SINK
SOUTH INTO THE AREA WITH SURFACE WINDS BECOMING NORTH TO NORTHEAST.
THIS DIFFERENTIAL TEMPERATURE ADVECTION REGIME WILL ENHANCE
ISENTROPIC UPGLIDE ACROSS THE BOUNDARY AND SUPPORT SOMEWHAT MORE
WIDESPREAD SHOWERS AND EMBEDDED CONVECTION AS THE SHORTWAVE MOVES
NORTHEAST ACROSS THE AREA.
PWAT VALUES REMAIN AT 1.5 INCHES OR HIGHER OVERNIGHT...SO ANY OF THE
STRONGER CONVECTION WILL PRODUCE LOCALLY HEAVY RAINFALL. DRY
ANTECEDENT CONDITIONS AND PROGRESSIVE STORM MOTION SHOULD PRECLUDE
ANY FLOODING CONCERNS. SEVERE WEATHER POTENTIAL REMAINS MINIMAL
GIVEN THE WEAK SHEAR...MARGINAL INSTABILITY...AND POOR DIURNAL
TIMING.
IT WILL REMAIN VERY WARM AND HUMID OVERNIGHT WITH LOWS ONLY IN THE
MID TO UPPER 60S ON THE LAKE PLAINS AND LOWER 60S ACROSS THE
SOUTHERN TIER VALLEYS. THE NORTH COUNTRY WILL DROP INTO THE UPPER
50S BEHIND THE WEAK FRONTAL BOUNDARY.
MONDAY MORNING EXPECT A RELATIVE LULL IN RAIN COVERAGE...ALTHOUGH A
FEW PASSING LIGHT SHOWERS CANNOT BE RULED OUT WITH THE WEAK LOW
LEVEL FRONTAL ZONE DRAPED OVER THE AREA. CONVECTION WILL BREAK OUT
AGAIN DURING THE AFTERNOON WITH DIURNAL DESTABILIZATION. EXPECT THE
BULK OF THE CONVECTION TO INITIALLY ASSOCIATE WITH THE LAKE BREEZE
BOUNDARIES...THEN SPREAD INLAND ACROSS THE GENESEE VALLEY...FINGER
LAKES...AND CENTRAL NY DURING THE MID TO LATE AFTERNOON. RAIN
COVERAGE SHOULD BE LOWEST NORTHEAST OF LAKES ERIE AND ONTARIO
INCLUDING BUFFALO AND WATERTOWN AS LAKE SHADOWS ATTEMPT TO FORM...
ALTHOUGH WITH SOME SYNOPTIC SCALE ASCENT IT MAY NOT REMAIN
COMPLETELY DRY IN THE LAKE SHADOWS.
PWAT VALUES REMAIN GREATER THAN 1.5 INCHES...SO AGAIN ANY STORMS MAY
PRODUCE LOCALLY HEAVY RAINFALL. MOST OF THE STORMS WILL REMAIN
PROGRESSIVE ENOUGH TO KEEP ANY FLOODING RISK LOW...ALTHOUGH IF
TRAINING DEVELOPS ALONG LAKE BREEZE BOUNDARIES SOME LOCAL FLOOD RISK
MAY DEVELOP. SEVERE WEATHER POTENTIAL REMAINS LOW...WITH RELATIVELY
WEAK INSTABILITY FEATURING TALL/SKINNY CAPE MORE FAVORABLE FOR HEAVY
RAIN. SHEAR REMAINS RELATIVELY WEAK AS WELL WITH MAX WIND SPEEDS OF
ONLY AROUND 30 KNOTS IN THE LOWEST 20K FEET OF THE COLUMN.
PERIODS OF CLOUD COVER MIXED WITH BREAKS OF SUN SHOULD ALLOW HIGHS
TO REACH THE LOWER 80S IN MOST AREAS MONDAY...WITH ONSHORE FLOW
KEEPING THE LAKESHORES MUCH COOLER. THE NORTH COUNTRY WILL REMAIN
NORTH OF THE STALLED FRONTAL BOUNDARY...WITH TEMPS ONLY IN THE 60S
NEAR THE SAINT LAWRENCE.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AFTER SEVERAL DAYS OF ABOVE NORMAL TEMPERATURES AND HUMIDITY WE WILL
SEE A SHARP TURN TO COOLER AND DRIER WEATHER AS AN ARCTIC COLD FRONT
SHIFTS EAST ACROSS WESTERN AND CENTRAL NEW YORK. LOW PRESSURE WILL
BE CENTERED EARLY MONDAY EVENING OVER NORTHERN WISCONSIN WITH THE
FRONT DROPPING SOUTH ACROSS MICHIGAN. STORMS WILL SHIFT EAST ACROSS
LAKE ERIE THEN WESTERN NEW YORK ALONG A PRE-FRONTAL TROUGH AND
50KNOT LOW LEVEL JET. THE ACTUAL FRONT APPEARS TO BE DELAYED BEHIND
THE STORMS BY A FEW HOURS. FORECAST CAPE AND SHEAR VALUES APPEAR TOO
LOW FOR ANY SEVERE THREAT BUT GUSTY WINDS FROM THE LLJ MAY BE PULLED
DOWN BY THE SHOWERS. PWATS AROUND 1.5 INCHES WHICH IS NEAR CLIMO MAX
FOR MID MAY WILL ALSO BRING A THREAT OF HEAVY RAIN WITH THE STORMS.
TEMPERATURES WILL ONLY SLIDE BACK TO AROUND 60 MONDAY NIGHT.
THE TURN TO COLDER WEATHER COMES TUESDAY AS THE ARCTIC FRONT SLIDES
EAST ACROSS THE REGION. 850MB TEMPS WILL SLIDE BACK TO NEAR 0C BY
TUESDAY EVENING AS THE 500MB TROUGH SHIFTS OVER THE LOWER GREAT
LAKES. SURFACE TEMPS NEAR 60F TO START THE DAY WILL DROP TO 50F BY
EVENING THEN 40F TUESDAY NIGHT. THE COOLING TEMPERATURES AND DRIER
AIR ALOFT BEHIND THE FRONT WILL STEEPEN LOW LEVEL LAPSE RATES
ALLOWING GUSTS FROM A 50KT 850MB JET TO MIX TO THE SURFACE.
SUSTAINED WINDS OF 20-30 WITH GUSTS 30-40 WILL BE POSSIBLE.
SCATTERED INSTABILITY SHOWERS MAY ALSO POP UP BEHIND THE FRONT
TUESDAY AND TUESDAY NIGHT.
WEDNESDAY AND WEDNESDAY NIGHT EXPANSIVE ARCTIC SOURCED HIGH PRESSURE
WILL BUILD EAST ACROSS THE GREAT LAKES WITH A NORTH WEST FLOW OF DRY
MODIFIED-ARCTIC AIR CONTINUING TO WORK ACROSS THE FORECAST AREA.
850MB TEMPS OF 0C WHICH IS ABOUT 6 DEGREES BELOW NORMAL WILL KEEP
HIGHS STRUGGLING TO REACH INTO THE 50S DESPITE THE STRONG MAY SUN.
WINDS SHOULD SLACKEN WITH ANOTHER CHANCE OF INLAND DIURNAL SHOWERS
IF ENOUGH SYNOPTIC MOISTURE REMAINS. TEMPERATURES WEDNESDAY NIGHT
WILL SLIP INTO THE 30S AND LOW 40S SO FROST MAY BECOME A CONCERN
WITH CLEAR SKIES AND LIGHT WINDS. THIS HAS BEEN HIGHLIGHTED IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE SURFACE HIGH CENTERS OVERHEAD ON THURSDAY WITH ANOTHER COOL DAY
EXPECTED THEN SHIFTS TO THE EAST COAST FRIDAY WITH A SOUTHERLY FLOW
WARMING TEMPERATURES BACK TOWARD NORMAL. ADVECTION OF EVEN WARMER
AND MORE MOIST AIR NEXT WEEKEND BRINGS BACK CHANCES OF SHOWERS LATER
FRIDAY INTO SATURDAY AS GLOBAL MODELS FORECAST A WAVE OF LOW
PRESSURE AND 500MB SHORTWAVE CUTTING EAST ACROSS PENNSYLVANIA.
TEMPERATURES THEN LOOK TO RISE ABOVE NORMAL BY NEXT SUNDAY AS THE
12Z GFS AND ECMWF BOTH SHOW EAST COAST 500MB RIDGING DEVELOPING
AGAIN
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
WHILE MAINLY VFR CONDITIONS WILL PREVAIL OVERNIGHT...THERE WILL BE A
COUPLE BATCHES OF SHOWERS AND THUNDERSTORMS THAT WILL WORK ACROSS
THE AREA FROM SOUTHWEST TO NORTHEAST OVERNIGHT. IN THE HEAVIEST
SHOWERS/THUNDERSTORMS CIGS/VIS COULD BECOME LIMITED TO MVFR/IFR
CONDITIONS...HOWEVER THESE REDUCTIONS WILL BE FAIRLY SHORT LIVED
WITH THE TRANSIENT/SCATTERED NATURE OF THE SHOWERS/THUNDERSTORMS.
THE ONE EXCEPTION TO THE WIDELY VFR CONDITIONS WILL BE LATE TONIGHT
AND MONDAY MORNING ACROSS THE SAINT LAWRENCE VALLEY...INCLUDING
KART. A COLD FRONT OVER SOUTHERN ONTARIO WILL SAG SOUTHWARD...WITH
AREAS OF LOW MVFR CIGS DEVELOPING BEHIND IT.
ON MONDAY EXPECT A RELATIVE LULL IN CONVECTION DURING THE MORNING...
ALTHOUGH A FEW PASSING LIGHT SHOWERS CANNOT BE RULED OUT. EXPECT
MORE CONVECTION DURING THE AFTERNOON WITH THE BULK OF IT FORMING
ALONG AND INLAND OF THE LAKE BREEZE BOUNDARIES. THESE STORMS WILL
PRODUCE AREAS OF BRIEF MVFR/IFR SIMILAR TO TODAY...WITH MAINLY VFR
BETWEEN THE MORE ORGANIZED AREAS OF CONVECTION.
OUTLOOK...
MONDAY NIGHT...VFR WITH BRIEF MVFR/IFR IN SCATTERED SHOWERS AND
THUNDERSTORMS.
TUESDAY AND WEDNESDAY...MAINLY VFR WITH A CHANCE OF A SHOWER.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
WINDS WILL REMAIN RELATIVELY LIGHT INTO MONDAY ON BOTH LAKES AS A
WARM AIRMASS AND RELATIVELY WEAK PRESSURE GRADIENT REMAINS IN PLACE.
ANY SCATTERED THUNDERSTORMS WHICH CROSS THE AREA WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY GUSTY WINDS AND HIGHER WAVES.
A COLD FRONT WILL CROSS THE AREA LATE MONDAY NIGHT AND TUESDAY.
BEHIND THIS FRONT MUCH COOLER AIR WILL SURGE INTO THE LOWER LAKES
WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS POSSIBLE TUESDAY
THROUGH WEDNESDAY AS WINDS INCREASE ALONG AND BEHIND THE COLD FRONT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...CHURCH/HITCHCOCK
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...CHURCH/HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1007 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL
PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE
NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL
THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 10 PM SUN...RAIN THIS EVENING HAS MOSTLY BEEN IN THE
SOUTHWEST COUNTIES. HOWEVER...AS REMNANTS OF ANA MOVE NORTH
NORTHEAST OVERNIGHT RAIN WILL SPREAD INTO THE REMAINING COUNTIES.
THEREFORE WILL LEAVE POPS AS IS. REMNANTS OF ANA CURRENTLY OVER
SE NC SLOWLY LIFTING NORTH NORTHEAST. CONVECTIVE BANDS OF RAIN
SHOWERS WITH EMBEDDED THUNDER...HEAVY AT TIMES...EXPECTED
OVERNIGHT PER MESOSCALE CONVECTIVE INITIATING MODELS. WILL LEAVE
FLOOD WATCH INTACT. ALSO...ISOLATED TOR THREAT MAY DEVELOP AS
FAVORABLE LOW LEVEL SHEAR VALUES INCRS OVERNIGHT AS CENTER OF ANA
MOVES THROUGH THE COASTAL PLAIN/INTERSTATE 95 CORRIDOR. HIGH RES
MODELS INDICATE AN UPTICK IN UPDRAFT HELICITY AFTER AROUND
04Z...AND WITH SFC WINDS STILL BACKED SSE...THIS WOULD YIELD INC
LOW LEVEL HELICITY AS H85MB WINDS VEER SWRLY. WILL CONTINUE TO
HIGHLIGHT THESE THREATS IN HWO. MUGGY OVERNIGHT LOWS WITH MOST
AREAS DROPPING NOW LOWER THAN 70 OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH 6 PM MONDAY/...
AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END
THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY
TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT
MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE
NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN
AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK
OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT.
HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD OF
SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR
SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLOUDY
SKIES THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING
ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY AFTERNOON.
DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF STRONG TO
SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING.
COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE
BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE
STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY
AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP
MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE.
MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED
SFC BNDRY LINGER OVER THE AREA.
AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO
NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE
SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT
SFC FRONT.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
AS OF 7 PM SUN...IFR/MVFR CONDITIONS OVER EASTERN NORTH CAROLINA
TAFS AS REMNANTS OF ANA OVER SE NORTH CAROLINA MOVES NORTH
NORTHEAST. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON
RAIN BANDS MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF
BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS REMNANTS OF ANA
BECOME MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED
PRECIPITATION WILL BECOME MORE STRATIFORM WITH LOWER CEILINGS. AS
ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING
AFTER 12Z.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT,
HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED PRECIPITATION MAY
SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING. MIXING WILL SCATTER
OUT CLOUD COVER BY MIDDAY TUESDAY THEN SCATTERED SHOWER AND
THUNDERSTORMS (SOME OF WHICH CUD BE STRONG/SEVERE) AFFECT THE AREA
TUESDAY AFTERNOON AND EVENING. DRYING AIRMASS BUILDS IN AFTER A COLD
FRONT PASSAGE LATE TUESDAY NIGHT WITH PREDOMINATE VFR EXPECTED
THEREAFTER.
&&
.MARINE...
AS OF 10 PM SUNDAY...LAND/BUOY OBS SHOW SOUTH TO SOUTHEAST FLOW
ACROSS THE MARINE ZONES...GENERALLY 15-20 KTS NORTH AND 20-25 KTS
SOUTH. SEAS RUNNING 3-6 FT. THE REMNANTS OF ANA WILL LIFT
NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING
SOUTHERLY AND INCRSG ACROSS ALL WATERS AND THE PAMLICO SOUND.
CURRENT SCA LOOKS IN GOOD SHAPE.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF
THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL KEEP
SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A COLD
FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A LULL
IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER POST
FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY. WINDS/SEAS
GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT DECREASES AT
THE COAST WITH HIGH BUILDING IN FROM THE NORTH.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF
HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER
SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST
RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH UNTIL 8 AM EDT MONDAY FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...HSA/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...HSA/BTC
MARINE...HSA/BTC/TL
HYDROLOGY...RF/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
712 PM EDT SUN MAY 10 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL
PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE
NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL
THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 7 PM SUN...CURRENT FORECAST ON TRACK AND WILL LEAVE AS IS.
REMNANTS OF ANA CURRENTLY OVER SE NC SLOWLY LIFTING NORTH
NORTHEAST. CONVECTIVE BANDS OF RAIN SHOWERS WITH EMBEDDED
THUNDER...HEAVY AT TIMES...EXPECTED OVERNIGHT PER MESOSCALE
CONVECTIVE INITIATING MODELS. WILL LEAVE FLOOD WATCH INTACT.
ALSO...ISOLATED TOR THREAT MAY DEVELOP AS FAVORABLE LOW LEVEL
SHEAR VALUES INCRS OVERNIGHT AS CENTER OF ANA MOVES THROUGH THE
COASTAL PLAIN/INTERSTATE 95 CORRIDOR. HIGH RES MODELS INDICATE AN
UPTICK IN UPDRAFT HELICITY AFTER AROUND 04Z...AND WITH SFC WINDS
STILL BACKED SSE...THIS WOULD YIELD INC LOW LEVEL HELICITY AS
H85MB WINDS VEER SWRLY. WILL CONTINUE TO HIGHLIGHT THESE THREATS
IN HWO. MUGGY OVERNIGHT LOWS WITH MOST AREAS DROPPING NOW LOWER
THAN 70 OVERNIGHT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH 6 PM MONDAY/...
AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END
THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY
TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT
MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE
NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN
AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK
OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT.
HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD OF
SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR
SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLOUDY
SKIES THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING
ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY AFTERNOON.
DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF STRONG TO
SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING.
COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE
BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE
STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY
AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP
MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE.
MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED
SFC BNDRY LINGER OVER THE AREA.
AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO
NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE
SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT
SFC FRONT.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
AS OF 7 PM SUN...IFR/MVFR CONDITIONS OVER EASTERN NORTH CAROLINA
TAFS AS REMNANTS OF ANA OVER SE NORTH CAROLINA MOVES NORTH
NORTHEAST. HRRR AND HIRESW-ARW MODEL HAVE A GOOD HANDLING ON
RAIN BANDS MOVING ACROSS THE REGION THROUGH TONIGHT. TIMING OF
BANDS WILL BE DIFFICULT TO ACCURATELY PREDICT BUT AS REMNANTS OF ANA
BECOME MORE EXTRATROPICAL THIS EVENING AND TONIGHT BANDED
PRECIPITATION WILL BECOME MORE STRATIFORM WITH LOWER CEILINGS. AS
ANA PULLS AWAY WINDS WILL SHIFT TO THE SW THEN W IN THE MORNING
AFTER 12Z.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY NIGHT,
HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED PRECIPITATION MAY
SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING. MIXING WILL SCATTER
OUT CLOUD COVER BY MIDDAY TUESDAY THEN SCATTERED SHOWER AND
THUNDERSTORMS (SOME OF WHICH CUD BE STRONG/SEVERE) AFFECT THE AREA
TUESDAY AFTERNOON AND EVENING. DRYING AIRMASS BUILDS IN AFTER A COLD
FRONT PASSAGE LATE TUESDAY NIGHT WITH PREDOMINATE VFR EXPECTED
THEREAFTER.
&&
.MARINE...
AS OF 7 PM SUNDAY...LAND/BUOY OBS SHOW SOUTH TO SOUTHEAST FLOW
ACROSS THE MARINE ZONES...GENERALLY 10-15 KTS NORTH AND 20-25 KTS
SOUTH. SEAS RUNNING 3-6 FT. THE REMNANTS OF ANA WILL LIFT
NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING
SOUTHERLY AND INCRSG ACROSS ALL WATERS AND THE PAMLICO SOUND.
CURRENT SCA LOOKS IN GOOD SHAPE.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF
THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL KEEP
SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A COLD
FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A LULL
IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER POST
FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY. WINDS/SEAS
GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT DECREASES AT
THE COAST WITH HIGH BUILDING IN FROM THE NORTH.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF
HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER
SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST
RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH MONDAY MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...HSA/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...HSA/BTC
MARINE...HSA/BTC/TL
HYDROLOGY...TL/RF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1035 AM EDT SAT MAY 9 2015
.SYNOPSIS...SUBTROPICAL STORM ANA WILL CONTINUE TO MEANDER OFF THE
SOUTH CAROLINA COAST THIS MORNING... THEN BEGIN TO DRIFT SLOWLY TO
THE NORTHWEST THIS AFTERNOON AND TONIGHT...REACHING THE COAST OF
SOUTH AND NORTH CAROLINA EARLY SUNDAY. THE STORM WILL WEAKEN AS IT
DRIFTS NORTHWARD OVER EASTERN NORTH CAROLINA SUNDAY AFTERNOON
THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1035 AM SATURDAY...
LATEST VISIBLE SAT AND SFC OBS CONTINUE TO SHOW STRATUS ACROSS OUR
N/NW ZONES ASSOC WITH THE MOIST MARINE LAYER THAT WAS ADVECTED IN
OVERNIGHT ON LOW LEVEL ENE FLOW. WHILE THIS STRATUS HAS DIMINISHED
IN COVERAGE SOME SINCE SUNRISE...IT MAY TAKE ANOTHER HOUR OR TWO
BEFORE IT COMPLETELY DISSIPATES. OTHERWISE...LATEST RADAR SHOWS
SPOTTY SPRINKLES APPROACHING THE COASTAL PLAIN AND A BAND OF SHOWERS
MOVING ONSHORE NORTH OF CAPE FEAR. MEANWHILE...LATEST MESO ANALYSIS
IS VERY SIMILAR TO YESTERDAY`S ANALYSIS...SHOWING A DECREASING TREND
IN MOISTURE AND INSTABILITY AS YOU HEAD WEST FROM THE COAST. IN
FACT...PWAT ON 12Z GSO SOUNDING WAS BELOW 1 INCH...WITH AVAILABLE
MOISTURE CONFINED TO THE LOWER LEVELS IN THE SHALLOW MARINE LAYER.
AS SUCH...LATEST HRRR APPEARS TO BE ON TRACK SHOWING THE
AFOREMENTIONED SPOTTY SHOWERS AND RAIN SHOWER BANDS GRADUALLY
DECREASING IN COVERAGE AND INTENSITY AS THEY MOVE WESTWARD. THE BEST
CHANCE FOR SAID SHOWERS IN OUR CWA APPEARS TO BE MAINLY EAST OF I-95
AND SOUTH OF THE HWY 64 CORRIDOR. FORECAST SOUNDINGS SUGGEST THAT BY
LATER THIS AFTERNOON AND THIS EVENING...THERE MAY BE ENOUGH MOISTURE
ADVECTION WESTWARD TO SUPPORT A SLIGHTLY IMPROVED RAIN CHANCES
ACROSS OUR W/NW ZONES...INCLUDING THE TRIAD. SO WHILE THE BEST RAIN
CHANCES WILL BE SOUTH AND EAST OF THE TRIANGLE TODAY...WE CAN`T
TOTALLY RULE OUT AN ISOLATED SHOWER OR TWO ANYWHERE IN OUR CWA LATER
TODAY.
PREV DISC AS OF 355 AM SATURDAY...WHILE SUBTROPICAL STORM ANA WILL
HAVE AN INFLUENCE ON OUR WEATHER ACROSS CENTRAL NC...BULK OF THE
EFFECTS WILL BE CONFINED TO THE FAR SE-EASTERN SECTIONS OF THE
FORECAST AREA.
ANA EXPECTED TO BEGIN A DRIFT TO THE NORTH NORTHWEST LATER TODAY IN
RESPONSE TO THE APPROACH OF A S/W CROSSING THE MID MS VALLEY. THIS
WILL WILL TEND TO SHIFT BETTER/DEEPER MOISTURE NWD INTO CENTRAL NC.
SPOKES OF VORTICITY ROTATING AROUND ANA COUPLED WITH AFTERNOON
HEATING SHOULD TRIGGER SCATTERED-NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS OVER THE EASTERN HALF OF THE FORECAST AREA WITH THE
BEST COVERAGE OF SHOWERS EAST AND SE OF THE TRIANGLE.
HIGH TEMPS THIS AFTERNOON WILL BE DICTATED BY THE AMOUNT OF SUN THAT
OCCURS LATE THIS MORNING-AFTERNOON. FAVOR MAX TEMPS NEAR 80-LOWER
80S THOUGH IF SHOWER COVERAGE SPOTTY AND LOW CLOUDS DEPART SOONER
THAN EXPECTED...LOW-MID 80S WILL BE THE NORM.
TONIGHT...ANA MOVES CLOSER TO THE COAST AND SHOULD BEGIN TO WEAKEN
AS IT INTERACTS MORE WITH LAND AND THE COOLER SHELF WATER CLOSER TO
SHORE. HIGHEST THREAT FOR SHOWERS WILL REMAIN OVER THE SE COUNTIES
THOUGH COULD SEE SHOWERS INCREASE IN COVERAGE OVERNIGHT FOR
LOCATIONS IMMEDIATELY SOUTH AND EAST OF THE TRIANGLE. SHOWERS
COVERAGE STILL APPEARS SPOTTY ENOUGH THAT HEAVY RAIN/LOCALIZED
FLOODING DOES NOT APPEAR TO BE A THREAT. MIN TEMPS IN THE 60S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 355 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT...ANA AND/OR THE REMNANTS OF ANA WILL BEGIN
A NORTHWARD TRACK ACROSS NE SC-EASTERN NC THIS PERIOD. BULK OF THE
MODERATE-BRIEFLY HEAVY RAIN ASSOCIATED WITH THIS SYSTEM SHOULD OCCUR
ALONG AND RIGHT OF THE TRACK. THUS...AREAS EAST OF I-95 HAVE THE
BEST CHANCE OF SEEING RAINFALL AMOUNTS BETWEEN A QUARTER AND A HALF
INCH WHILE LOCATIONS WEST OF I-95 WILL SEE MUCH LIGHTER TOTALS AND
AREAS WEST OF HIGHWAY 1 MAY SEE LITTLE IF ANY RAIN WITH THIS SYSTEM.
HAVE INCREASED POPS TO HIGH LIKELY-LOW END CATEGORICAL ALONG OUR FAR
SE-EASTERN PERIPHERY. THIS MAY NEED TO BE ADJUSTED FARTHER UPWARD AS
MODEL GUIDANCE COMES INTO BETTER CONSENSUS. SINCE BULK OF HEAVY OR
LOCALLY EXCESSIVE RAINFALL EXPECTED EAST OF OUR REGION... A FLASH
FLOOD WATCH IS NOT NEEDED AT THIS TIME.
BASED ON CURRENT TRACK OF THE SYSTEM...THERE MAY BE A MINIMAL
TORNADO THREAT OVER OUR FAR SE COUNTIES SUNDAY AFTERNOON...AND ALONG
OR EAST OF THE I-95 CORRIDOR SUNDAY NIGHT. IF SYSTEM TRACKS FARTHER
TO THE EAST(CLOSER TO THE COAST)...THEN TORNADO RISK WILL DIMINISH
APPRECIABLY. OTHERWISE EXPECT STRONGEST GUSTS ASSOCIATED WITH ANA TO
AFFECT OUR FAR SOUTHERN-SE LOCATIONS LATE TONIGHT-SUNDAY MORNING
WITH GUSTS 35-40 MPH CONFINED TO AREAS SOUTH OF A FAYETTEVILLE-
CLINTON-GOLDSBORO LINE.
MAX TEMPS SUNDAY DEPENDENT ON EXTENT/TIMING OF RAIN SHOWERS. EXPECT
HIGH TEMPS TO VARY FROM THE LOWER 80S WEST WHERE PARTIAL SUNSHINE
MAY OCCUR TO THE UPPER 70S/NEAR 80 CLOSER TO THE I-95 CORRIDOR. -WSS
MONDAY AND MONDAY NIGHT...STEERING FLOW WILL BE INCREASING AND ANA
WILL BEGIN TO ACCELERATE NORTH UP THE COASTAL PLAIN ON MONDAY...AND
OUT OF THE AREA EARLY MONDAY NIGHT. WIDESPREAD AND HEAVIER
CONVECTION WILL LIE ALONG AND EAST OF THE TRACK WHICH WILL GENERALLY
PARALLEL I-95...SHIFTED MORE TOWARDS THE NORTHERN COASTAL PLAIN
LATER IN THE DAY. WILL HAVE POPS GRADUATED WITH LOWER CHANCES WEST
TO HIGH CHANCES EAST WITH PRECIP ESTIMATES FROM A QUARTER INCH WEST
TO 5 OR 6 TENTHS OF AN INCH IN THE FAR EAST. PRECIP ESTIMATES IN THE
EAST COULD EASILY BE ON THE LOW SIDE GIVEN THE CHANCE FOR HEAVY
SHOWERS IN THE HIGH PW...~2 INCHES...AND STRONGLY CONVERGENT
CONDITIONS ALONG AND EAST OF THE LOW TRACK. WINDS IN THE WEST WILL
BE GENERALLY LESS THAN 10 MPH...AND 10 TO 15 MPH IN THE EAST WITH
GUSTS TO 20 MPH. THE WINDS WILL BE MAINLY FROM THE NORTHERLY
QUADRANTS EITHER SIDE OF THE LOW EARLY...BACKING AROUND AS THE DAY
PROGRESSES AND FINALLY SETTLING TO SOUTHWEST BY LATE DAY ONCE THE
LOW HAS LIFTED OUT. ONGOING HIGH TEMPERATURE FORECAST IN THE 82-85
RANGE LOOKS SPOT ON. POPS WILL FALL OFF TO LOW CHANCE OVERNIGHT AS
NVA INCREASES BEHIND THE SYSTEM ALONG WITH DRYING ALOFT IN WESTERLY
FLOW. MINS WILL BE MILD IN SOUTHWEST FLOW...65 TO 70.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 330 AM SATURDAY...
STILL LOOKING AT A DECENT CHANCE FOR AT LEAST SCATTERED CONVECTIVE
COVERAGE ON TUESDAY. WILL HAVE A LINGERING VERY MOIST AND WARM
AIRMASS IN PLACE AHEAD OF AN APPROACHING FRONT...WITH MID LEVEL
DRYING AND LAPSE RATES OF >6.0C/KM...RESULTING IN CAPE OF AROUND
1000 JOULES IN THE EAST DURING PEAK HEATING. SOME MIXED SIGNALS WITH
THE LATEST GFS...WHICH SHOWS MUCH FASTER PROGRESSION OF THE
DRYING...WHICH WOULD LIMIT INSTABILITY IN THE WEST EARLY IN THE DAY.
WHILE IN THE EAST...THE MAIN LIMITING FACTOR WILL BE RELATIVELY WEAK
LOW LEVEL FORCING. AT THIS POINT...WILL MAINTAIN ONGOING 30 POPS
WITH HIGHS IN THE MID TO UPPER 80S.
DRY AND MORE SEASONABLE WEATHER IS ON TAP FOR MID TO LATE WEEK AS
HIGH PRESSURE MIGRATES ACROSS THE OHIO VALLEY. ASSOCIATED NORTHERLY
FLOW AND COOL AIR ADVECTION WILL RESULT IN HIGHS AROUND 80 ON
WEDNESDAY...AND IN THE 75 TO 80 RANGE ON THURSDAY. INCREASING
MOISTURE IN RETURN FLOW AS THE HIGH MOVES OFFSHORE WILL BEGIN TO
PRODUCE UPSLOPE PRECIP IN THE MOUNTAIN LATE THURSDAY NIGHT...WHICH
WILL GRADUALLY SPREAD EAST INTO CENTRAL NC DURING THE DAY FRIDAY.
HIGHS FRIDAY WILL BE A LITTLE COOLER WITH RESULTING HEAVIER
CLOUDINESS...MAINLY MID 70S. LOWS EACH MORNING WILL BE IN THE LOWER
60S WEDNESDAY MORNING...AND MID AND UPPER 50S THURSDAY AND
FRIDAY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...
WIDESPREAD LIFR/IFR CONDITIONS DUE TO CEILINGS WILL SLOWLY
IMPROVE THROUGH 15Z. EXPECT LOW CLOUDS TO EVENTUALLY LIFT INTO A
SCATTERED CU FIELD BY MID DAY. ADDITIONAL HEATING WILL LIKELY CAUSE
AREAS OF BROKEN CEILINGS BETWEEN 3500-4500 FT...ESPECIALLY IN
VICINITY OF KRDU...KRWI AND KFAY. IN ADDITION...THE AFTERNOON
HEATING WILL LIKELY INITIATE THE DEVELOPMENT OF SCATTERED SHOWERS
OVER THE EASTERN HALF OF THE FORECAST AREA. IMPACTS...HOWEVER... AT
ANY PARTICULAR TERMINAL DIFFICULT TO PINPOINT AT THIS TIME THOUGH
THINK THE BEST CHANCE IS IN THE VICINITY OF KFAY. WITH LOSS OF
HEATING THE BULK OF THE SCATTERED SHOWERS WILL DIMINISH/DISSIPATE.
CIRCULATION AROUND TROPICAL STORM ANA WILL MAINTAIN A STEADY NE
BREEZE ACROSS THE REGION WITH SUSTAINED WINDS NEAR 15 MPH HIGHLY
PROBABLE NEAR KFAY AND KRWI.
ANA EXPECTED TO MOVE NORTH TONIGHT AND SUNDAY...BRINGING AN
INCREASING CHANCE FOR WIDESPREAD MVFR/IFR CEILINGS ALONG WITH
SCATTERED-NUMEROUS SHOWERS. THESE IMPACTS APPEAR MOST LIKELY LATE
TONIGHT AND SUNDAY IN VICINITY OF KFAY AND KRWI...AND LESS LIKELY IN
THE TRIAD. THE THREAT FOR ADVERSE AVIATION CONDITIONS WILL PERSIST
THROUGH MONDAY MORNING IN THE EAST..THEN GRADUALLY IMPROVE MONDAY
AFTERNOON. SUSTAINED WINDS CLOSE TO 20 MPH WITH GUSTS 30-40 MPH WILL
IMPACT AREAS CLOSE TO KFAY AND KGSB LATE TONIGHT THROUGH SUNDAY
MORNING. SFC WINDS WILL SLOWLY SUBSIDE SUNDAY AFTERNOON.
MOST OF THE REGION WILL SEE PERIODS OF MVFR CONDITIONS MONDAY NIGHT
INTO TUESDAY AS A FRONTAL SYSTEM APPROACHES FROM THE WEST...CROSSING
OUR REGION TUESDAY. A RETURN TO WIDESPREAD VFR CONDITIONS EXPECTED
BY WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...RAH/WSS
SHORT TERM...WSS/MLM
LONG TERM...MLM
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
937 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 932 PM CDT SUN MAY 10 2015
CONSIDERED BRIEFLY EXPANDING THE WARNING EAST A FEW COUNTIES. AFTER
CLOSE SCRUTINY OF SURFACE REPORTS WHICH ARE ALL RAIN AT THIS
TIME...CANNOT SEE ENOUGH REASON TO EXPAND THE WARNING EAST AND
NORTH. WILL LEAVE AS IS. CURRENT HRRR TRENDS DEFINITELY SHOW
INCREASING MOISTURE. BUT NAM ALSO HAS H850 TEMPS INCREASING A
DEGREE OR SO. SO DO NOT THINK THE PRECIP WILL TURN OVER TO SNOW
EARLY ENOUGH TO WARRANT EXPANSION OF THE WARNING. THINK THE
ADVISORY SHOULD COVER. CURRENT FORECAST HEADLINES LOOK GOOD. WILL
SEE RAIN CHANGE TO SNOW AFTER MIDNIGHT.
UPDATE ISSUED AT 719 PM CDT SUN MAY 10 2015
LATEST RADAR TRENDS SHOW A MOISTURE CONVEYOR FROM NORTHEAST SOUTH
DAKOTA INTO CENTRAL NORTH DAKOTA. HRRR MODEL FORECASTS A H700 LOW
TO DEEPEN AND CLOSE OFF AS IT MOVES NORTHEAST INTO SOUTHEAST
NORTH DAKOTA DURING THE NEXT 9 HOURS. THIS SHOULD SET UP
INCREASING PRECIPITATION ACROSS SOUTH CENTRAL THROUGH THE JAMES
RIVER VALLEY. WILL HAVE TO MONITOR SNOW AND RAIN AREAS CLOSELY.
NO CHANGES AT THIS TIME.
UPDATE ISSUED AT 412 PM CDT SUN MAY 10 2015
ADDED A SLIGHT CHANCE OF THUNDERSTORMS TO LAMOURE AND DICKEY
COUNTIES. SEVERAL CELLS ARE MOVING NORTH FROM NORTHEAST SOUTH
DAKOTA. THIS SHOULD LAST THROUGH 7 PM.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN MAY 10 2015
WINTER STORM MAIN HIGHLIGHT FOR THE SHORT TERM PERIOD.
CURRENTLY...INITIAL DEFORMATION ZONE CONTINUES BUT HAS SHOWN
SIGNS OF DISSIPATION THE LAST HOUR OR TWO ACROSS SOUTH CENTRAL
NORTH DAKOTA. DRY SLOT WORKING NORTH INTO MY SOUTHEAST WITH ONLY
ISOLATED RADAR RETURNS NOW. PRECIP TYPE HAS BEEN BOUNCING AROUND
FROM RAIN OR SNOW MANY PLACES. THE EXCEPTION WAS ACROSS PARTS OF
THE SOUTH CENTRAL WHERE 8 INCHES WAS REPORTED EARLIER IN SELFRIDGE
AND 3-5 FROM HAZELTON...WISHEK...NAPOLEON AND STRASBURG.
ALL MODELS DEPICT ANOTHER DEFORMATION ZONE AND MOISTURE SURGE
ACROSS MY SOUTHEASTERN THIRD...MAINLY EAST AND SOUTHEAST OF
BISMARCK. QUESTION IS THE EXACT PLACEMENT OF THIS FEATURE AND HOW
MUCH QPF AND/OR SNOW WILL FALL TONIGHT. CURRENTLY HAVE ANOTHER 5
INCHES FORECAST ON TOP OF THE 3-5 WHICH ALREADY OCCURRED...BUT
EVEN THIS IS QUESTIONABLE WITH THE GREAT UNCERTAINTY WITH
TEMPERATURES. OVERALL DID NOT FEEL CONFIDENT ENOUGH TO UPGRADE
KIDDER...EMMONS...LOGAN...AND MCINTOSH TO A WARNING AND WILL LEAVE
THEM IN AN ADVISORY. THE EVENING SHIFT WILL CLOSELY MONITOR SO AN
UPGRADE IS STILL POSSIBLE OVER THE NEXT SEVERAL HOURS.
NOT MUCH AT ALL OCCURRED IN THE SOUTHWEST TODAY SO REMOVED
BOWMAN...SLOPE...AND STARK FROM HEADLINES...AND TRANSITIONED ADAMS
AND HETTINGER INTO AN ADVISORY WITH ONLY 3-4 INCHES REPORTS AND
ZERO IMPACTS.
WRAP AROUND RAIN/SNOW SLOWLY MOVES EAST TONIGHT INTO MONDAY
MORNING...EXITING OFF TO OUR EAST LATE MONDAY INTO MONDAY EVENING.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN MAY 10 2015
ACTIVE FLOW ALOFT WILL PRODUCE FREQUENT CHANCES FOR WIDESPREAD
PRECIPITATION THROUGH THE EXTENDED.
CHANCES FOR RAIN AND SNOW ARE EXPECTED TO LINGER OVER EASTERN AREAS
OF THE STATE THROUGH MONDAY NIGHT...AS A BROAD UPPER LEVEL TROUGH
CONTINUES TO SLOWLY MOVE EASTWARD ACROSS THE NORTHERN PLAINS.
THE CURRENT DETERMINISTIC AND ENSEMBLE MODELS ARE PROJECTING
SOUTHWEST FLOW ALOFT BY WEDNESDAY AND CONTINUING INTO SATURDAY. AS A
RESULT...LEE TROUGHING IS EXPECTED AT THE SURFACE WITH MOISTURE
TRANSPORT AND ATMOSPHERIC INSTABILITY CREATING NUMEROUS CHANCES FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS.
CONTINUED CHANCES FOR WIDESPREAD PRECIPITATION ARE POSSIBLE...AS
ANOTHER UPPER LEVEL LOW IS PROJECTED OVER THE NORTHERN PLAINS BY
THE END OF THE PERIOD...MODELS ARE VARIED ON TIMING/LOCATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 719 PM CDT SUN MAY 10 2015
LARGE SPRING STORM PRODUCING WIDESPREAD IFR CONDITIONS ACROSS
SOUTH CENTRAL AND SOUTHEAST NORTH DAKOTA. KBIS-KJMS WILL GENERALLY
REMAIN IFR IN RAIN AND SNOW CHANGING TO ALL SNOW THROUGH THE
NIGHT. CONDITIONS IMPROVING TO MVFR MONDAY. KISN-KMOT WILL REMAIN
NORTH OF THE STORM WITH VFR. KDIK WILL SEE MVFR IMPROVING TO VFR
AFTER 09Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR
NDZ020-041-044.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT MONDAY FOR NDZ022-023-025-
035>037-046-047-050.
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ034-
042-045.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...AC
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
729 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 719 PM CDT SUN MAY 10 2015
LATEST RADAR TRENDS SHOW A MOISTURE CONVEYOR FROM NORTHEAST SOUTH
DAKOTA INTO CENTRAL NORTH DAKOTA. HRRR MODEL FORECASTS A H700 LOW
TO DEEPEN AND CLOSE OFF AS IT MOVES NORTHEAST INTO SOUTHEAST
NORTH DAKOTA DURING THE NEXT 9 HOURS. THIS SHOULD SET UP
INCREASING PRECIPITATION ACROSS SOUTH CENTRAL THROUGH THE JAMES
RIVER VALLEY. WILL HAVE TO MONITOR SNOW AND RAIN AREAS CLOSELY.
NO CHANGES AT THIS TIME.
UPDATE ISSUED AT 412 PM CDT SUN MAY 10 2015
ADDED A SLIGHT CHANCE OF THUNDERSTORMS TO LAMOURE AND DICKEY
COUNTIES. SEVERAL CELLS ARE MOVING NORTH FROM NORTHEAST SOUTH
DAKOTA. THIS SHOULD LAST THROUGH 7 PM.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN MAY 10 2015
WINTER STORM MAIN HIGHLIGHT FOR THE SHORT TERM PERIOD.
CURRENTLY...INITIAL DEFORMATION ZONE CONTINUES BUT HAS SHOWN
SIGNS OF DISSIPATION THE LAST HOUR OR TWO ACROSS SOUTH CENTRAL
NORTH DAKOTA. DRY SLOT WORKING NORTH INTO MY SOUTHEAST WITH ONLY
ISOLATED RADAR RETURNS NOW. PRECIP TYPE HAS BEEN BOUNCING AROUND
FROM RAIN OR SNOW MANY PLACES. THE EXCEPTION WAS ACROSS PARTS OF
THE SOUTH CENTRAL WHERE 8 INCHES WAS REPORTED EARLIER IN SELFRIDGE
AND 3-5 FROM HAZELTON...WISHEK...NAPOLEON AND STRASBURG.
ALL MODELS DEPICT ANOTHER DEFORMATION ZONE AND MOISTURE SURGE
ACROSS MY SOUTHEASTERN THIRD...MAINLY EAST AND SOUTHEAST OF
BISMARCK. QUESTION IS THE EXACT PLACEMENT OF THIS FEATURE AND HOW
MUCH QPF AND/OR SNOW WILL FALL TONIGHT. CURRENTLY HAVE ANOTHER 5
INCHES FORECAST ON TOP OF THE 3-5 WHICH ALREADY OCCURRED...BUT
EVEN THIS IS QUESTIONABLE WITH THE GREAT UNCERTAINTY WITH
TEMPERATURES. OVERALL DID NOT FEEL CONFIDENT ENOUGH TO UPGRADE
KIDDER...EMMONS...LOGAN...AND MCINTOSH TO A WARNING AND WILL LEAVE
THEM IN AN ADVISORY. THE EVENING SHIFT WILL CLOSELY MONITOR SO AN
UPGRADE IS STILL POSSIBLE OVER THE NEXT SEVERAL HOURS.
NOT MUCH AT ALL OCCURRED IN THE SOUTHWEST TODAY SO REMOVED
BOWMAN...SLOPE...AND STARK FROM HEADLINES...AND TRANSITIONED ADAMS
AND HETTINGER INTO AN ADVISORY WITH ONLY 3-4 INCHES REPORTS AND
ZERO IMPACTS.
WRAP AROUND RAIN/SNOW SLOWLY MOVES EAST TONIGHT INTO MONDAY
MORNING...EXITING OFF TO OUR EAST LATE MONDAY INTO MONDAY EVENING.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN MAY 10 2015
ACTIVE FLOW ALOFT WILL PRODUCE FREQUENT CHANCES FOR WIDESPREAD
PRECIPITATION THROUGH THE EXTENDED.
CHANCES FOR RAIN AND SNOW ARE EXPECTED TO LINGER OVER EASTERN AREAS
OF THE STATE THROUGH MONDAY NIGHT...AS A BROAD UPPER LEVEL TROUGH
CONTINUES TO SLOWLY MOVE EASTWARD ACROSS THE NORTHERN PLAINS.
THE CURRENT DETERMINISTIC AND ENSEMBLE MODELS ARE PROJECTING
SOUTHWEST FLOW ALOFT BY WEDNESDAY AND CONTINUING INTO SATURDAY. AS A
RESULT...LEE TROUGHING IS EXPECTED AT THE SURFACE WITH MOISTURE
TRANSPORT AND ATMOSPHERIC INSTABILITY CREATING NUMEROUS CHANCES FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS.
CONTINUED CHANCES FOR WIDESPREAD PRECIPITATION ARE POSSIBLE...AS
ANOTHER UPPER LEVEL LOW IS PROJECTED OVER THE NORTHERN PLAINS BY
THE END OF THE PERIOD...MODELS ARE VARIED ON TIMING/LOCATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 719 PM CDT SUN MAY 10 2015
LARGE SPRING STORM PRODUCING WIDESPREAD IFR CONDITIONS ACROSS
SOUTH CENTRAL AND SOUTHEAST NORTH DAKOTA. KBIS-KJMS WILL GENERALLY
REMAIN IFR IN RAIN AND SNOW CHANGING TO ALL SNOW THROUGH THE
NIGHT. CONDITIONS IMPROVING TO MVFR MONDAY. KISN-KMOT WILL REMAIN
NORTH OF THE STORM WITH VFR. KDIK WILL SEE MVFR IMPROVING TO VFR
AFTER 09Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR
NDZ020-041-044.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT MONDAY FOR NDZ022-023-025-
035>037-046-047-050.
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ MONDAY FOR NDZ034-
042-045.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...AC
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 1143 PM CDT FRI MAY 8 2015
KEPT FCST CLOUD COVER AND TEMPS FROM 10 PM UPDATE AS IS. STILL
HAVE CLEARING AREA TRYING TO EDGE SOUTH HALLOCK TO CROOKSTON AND A
TAD WEST INTO GRAFTON/GRAND FORKS. OTHER LARGER CLEAR AREA REMAINS
PARK RAPIDS TO FARGO SOUTHWARD AND A SMALLER AREA AROUND LAKE OF
THE WOODS. LATEST HRRR SHOWS ABOUT STEADY IN TERMS OF CLOUD
COVER. TEMPS A FEW UPPER 20S IN CLEARER AREAS....BUT OTHERWISE LOW
TO MID 30S AS ADVERTISED. KEPT FROST ADVISORY BUT DO THINK WITH
SOME WIND AND MANY CLOUD AREAS AN ACTUAL FROST IS NOT LIKELY...BUT
TEMPS CERTAINLY IN THE COLD RANGE WHERE TENDER PLANTS NEED PROTECTION.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 250 PM CDT FRI MAY 8 2015
THE MAIN CHALLENGE WILL BE FROST CONCERNS TONIGHT THEN THE LARGE
STORM SYSTEM AND QPF POTENTIAL LATE SAT NIGHT THROUGH MONDAY. THE
GFS/ECWMF ARE IN VERY GOOD AGREEMENT AND WILL FOLLOW...WITH THE
NAM FURTHER SOUTH BUT FOR NOW WILL DISCOUNT FOR THE MOST PART
SINCE ITS THE ODD MODEL OUT.
FOR TONIGHT...WE WILL ISSUE A FROST ADVISORY FOR THE ENTIRE REGION
WITH A COLD AIRMASS IN PLACE. SOME CLEARING SHOULD ALLOW TEMPS TO
DROP TO AROUND 30 NORTH AND LOW/MID 30S ELSEWHERE. IF WINDS
DECOUPLE...THEN WE COULD BE CLOSE TO A FREEZE WARNING AND THE
EVENING CREW WILL HAVE TO MONITOR.
ON SATURDAY...IT SHOULD BE DRY WITH CLOUDS INCREASING LATER IN THE
AFTERNOON IN THE SOUTH. IT WILL REMAIN COOL AND COULD BE EVEN
COLDER IF CLOUDS HANG AROUND LONGER OR INCREASE QUICKER THAN EXPECTED.
FOR SAT NIGHT...MOISTURE CONVERGENCE INCREASES AHEAD OF DEEP LOW
THAT WILL DEVELOP IN THE CENTRAL PLAINS. THE CHANCE FOR RAIN WILL
INCREASE INTO THE SOUTHERN FORECAST AREA BY 6Z SUNDAY...AND WILL
INCREASE POPS TO CATEGORICAL THEREAFTER.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 PM CDT FRI MAY 8 2015
ON SUNDAY...EXPECT RAIN...PERHAPS MODERATE TO HEAVY AT TIMES TO
SPREAD FROM SOUTH TO NORTH BY LATE MORNING OR EARLY AFTERNOON.
THERE WILL BE STRONG SYNOPTIC/DYNAMIC LIFTING PER QG/MID LEVEL
FGEN AND ISENTROPIC FIELDS. THERE WILL BE ABOUT 1 INCH PWATS VERY
CLOSE TO THE SOUTHERN FA...THAT WILL FORM A LARGE DEFORMATION RAIN
BAND. TEMPS WILL ALSO BE COOL...AND IT WILL BE WINDY WITH 40-50KT
TO MIX FROM 925-850MB. WE MAY NEED A WIND ADVISORY FOR AT LEAST
THE WESTERN AREAS...ALTHOUGH WITH EASTERLY SFC WINDS THIS USUALLY
IS NOT A FAVORABLE DIRECTION FOR HIGH WINDS...BUT THEY WILL BE
NEAR WIND ADVISORY LEVELS FOR SURE AT LEAST. TEMPS WILL CONTINUE
TO BE COOL AND PROBABLY REMAIN IN THE 40S GIVEN CLOUDS AND PRECIP.
FOR SUNDAY NIGHT...THE COLUMN COULD COOL SUFFICIENTLY IN AT LEAST
THE WESTERN AREAS FOR SOME SNOW TO MIX IN. WE WILL HAVE TO MONITOR
THIS THREAT SINCE TODAYS MODELS HAVE GOTTEN A BIT COOLER...SO
CAN/T RULE OUT SOME WET SNOW MIXING IN LATE AT NIGHT IF HEAVIER
BANDS OF PRECIP DEVELOP. GIVEN THERE IS STRONG MID LEVEL
FGEN...BANDED PRECIP COULD ALSO OCCUR.
ON MONDAY...THE LOW SHOULD SLOWLY PULL AWAY FROM THE REGION...BUT
A LARGE WRAPAROUND/DEFORMATION RAIN BAND WILL PERSIST MOST OF THE
DAY. QPF AMOUNTS FROM LATE SAT NIGHT THROUGH MONDAY WILL LIKELY
TOTAL AROUND 2 INCHES IN THE SOUTH TO AROUND 0.50 INCHES IN THE
NORTH. THIS COULD CHANGE BASED ON THE EVENTUAL TRACK OF THE
LOW...BUT SOME HIGHER QPF TOTALS APPEAR MORE LIKELY THROUGH THE
EVENT. TEMPS WILL CONTINUE ON THE COLD SIDE.
FOR MON NIGHT THROUGH FRI...WE SHOULD SEE A BREAK WITH DRIER BUT
COOL WEATHER TUESDAY INTO TUESDAY NIGHT...BUT THIS BREAK BETWEEN
SYSTEMS WILL BE SHORT LIVED. ANOTHER CENTRAL PLAINS LOW WILL LIFT
INTO THE NORTHERN TIER MID WEEK AND BRING MORE RAIN SHOWERS TO THE
REGION. BOTH MODELS AGREE WITH THIS...HOVER THE GFS IS SLIGHTLY
FASTER. CHANCES DECREASE FOR THE LATTER PART OF THE WEEK HOWEVER
THERE IS A SLIGHT CHANCE FOR LINGERING SHOWERS IN THE AREA ON BOTH
THURSDAY AND FRIDAY. HOWEVER...TEMPERATURES WILL RISE INTO THE 70S
BY FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1143 PM CDT FRI MAY 8 2015
TOUGH AVIATION FCST FOR THE NEXT 12 HOURS AS UNSURE HOW STRATOCU
CLOUDS WILL BEHAVE. DID KEEP FARGO SCATTERED CLOUDS THRU MID
MORNING THEN SOME HIGHER VFR TYPE CLDS MIDDAY SATURDAY INTO THE
AFTN/EVE. GRAND FORKS AND TVF TRIED TO SCATTER OUT OVERNIGHT. KEPT
BEMIDJI AND DEVILS LAKE IN CLOUDS. WINDS NORTHERLY 5-10 KTS
OVERNIGHT TURNING A BIT MORE NORTHEAST AT 10-15 KTS SATURDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FROST ADVISORY UNTIL 9 AM CDT SATURDAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
MN...FROST ADVISORY UNTIL 9 AM CDT SATURDAY FOR MNZ001>009-013>017-
022>024-027>032-040.
&&
$$
UPDATE...RIDDLE
SHORT TERM...DK
LONG TERM...DK/SPEICHER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1221 PM EDT SAT MAY 9 2015
.SYNOPSIS...
A COLD FRONT OVER THE CENTRAL GREAT LAKES WILL STALL NEAR LAKE
ERIE BY SUNDAY. LOW PRESSURE DEVELOPING OVER THE PLAINS STATES
WILL TRACK ACROSS THE GREAT LAKES MONDAY AND THE ASSOCIATED COLD
FRONT WILL PUSH ACROSS THE AREA MONDAY NIGHT. COOLER WEATHER WILL
RETURN BY TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID LEVEL DEBRIS CLOUDS FROM THE MORNING SHOWERS WORKING EAST
ACROSS THE FORECAST AREA. THE CLOUD PATCH SHOULD SHRINK AND SHIFT
EAST THIS AFTERNOON. LOTS OF RIDGING ALOFT AND DECIDED THAT THE
"LIKELY" WORDING IN THE EARLIER FORECAST WAS PROBABLY A LITTLE TOO
AGGRESSIVE. CANNOT RULE OUT SOME SHOWERS/THUNDERSTORMS THIS
AFTERNOON BUT WITH THE FRONT STILL WELL TO THE NORTH THERE IS NOT
MUCH OF A TRIGGER. THE MOISTURE IS SLIGHTLY DEEPER ACROSS
NORTHWEST OHIO WHICH WILL HELP IN THE DEVELOPMENT AND THE CLOUD
PATCH COULD CREATE A DIFFERENTIAL HEATING SITUATION ACROSS EXTREME
NORTHEAST OHIO AND NORTHWEST PA WHICH COULD TRIGGER SOME
SHOWERS/STORM. WENT WITH A "CHANCE" IN MOST AREAS.
HIGHS IN THE MID TO UPPER 80S. THE BEST CHANCE FOR A RECORD HIGH
MIGHT BE AT ERIE PA (OLD RECORD 86 1880). ELSEWHERE MAYBE TOO MANY
CLOUDS TO GET QUITE AS WARM AS YESTERDAY...PERHAPS JUST A DEGREE
OR TWO SHY OF THE RECORDS WHICH ARE MOSTLY IN THE UPPER 80S?
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
EXPECT FIRST WAVE OF CONVECTION TO MOVE EAST OF THE AREA TOWARD
MIDNIGHT LOCAL...THEN A DRY PERIOD UNTIL THE SECOND WAVE OF
CONVECTION DEVELOPS SOMETIME SUNDAY AFTERNOON. MODELS NOT IN GOOD
AGREEMENT ON TIMING OR LOCATION. BASICALLY WENT WITH LIKELY POPS
AWAY FROM THE LAKESHORE LATE SUNDAY AFTERNOON AND EVENING. MODELS
CONTINUE TO BE IN REASONABLE AGREEMENT MOVING ANOTHER LOW PRESSURE
SYSTEM INTO THE CENTRAL LAKES MONDAY NIGHT...DRAGGING COLD FRONT
ACROSS THE FORECAST AREA. SO BEST CHANCE OF CONVECTION REMAINS
MONDAY AFTERNOON INTO THE OVERNIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THOSE PEOPLE WANTING COOLER WEATHER WILL GET THEIR WISH DURING THE
LONG TERM PERIOD. STRONG CANADIAN HIGH PRESSURE WILL BUILD OVER THE
REGION FROM THE NORTHWEST FOR THE SECOND HALF OF THE WORKWEEK.
THERE WILL BE A DISTINCT AIR MASS CHANGE WITH HIGHS STRUGGLING TO
REACH 60 ON WEDNESDAY. BY FRIDAY TEMPS WILL BE BACK CLOSE TO
NORMAL. WILL CONTINUE WITH A DRY FORECAST FOR THE ENTIRE THREE DAY
PERIOD BUT PRECIP COULD BE KNOCKING ON THE DOOR TO THE SOUTHWEST
FRIDAY NIGHT. HAVE USED A BLEND OF GUIDANCE TEMPS FOR THE PERIOD.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SOME RADAR RETURNS SHOWING UP ALONG THE I-75 CORRIDOR. MOST OF
THIS IS VERY LIGHT RAIN IF IT IS REACHING THE GROUND AT ALL. THE
LATEST HRRR SUGGESTS THIS ACTIVITY WILL MOVE OFF TO THE NNE AND
DISSIPATE THE NEXT COUPLE OF HOURS. STILL EXPECTING ANOTHER ROUND
OF SHOWERS AND STORMS LATER TODAY. BASED ON NEW GUIDANCE HAVE
SLOWED DOWN THE START AN HOUR OR TWO MOST AREAS. GIVEN LACK OF
FORCING AND UPPER SORT ANY STORMS THAT DO DEVELOP WITH BE OF THE
GARDEN VARIETY. THE PRECIP SHOULD QUICKLY END FROM WEST TO EAST
AFTER 00Z. LIGHT FLOW WILL BECOME S TO SW BY MIDDAY. SOME GUSTS
OVER 20 KNOTS ARE POSSIBLE LATER TODAY.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS THROUGH
MONDAY NIGHT.
&&
.MARINE...
MAINLY SOUTH TO SOUTHWEST FLOW UNDER 15 KNOTS IS EXPECTED ON THE
LAKE INTO MONDAY. A COLD FRONT WILL EVENTUALLY CROSS THE LAKE
SOMETIME EARLY TUESDAY AS LOW PRESSURE MOVES ACROSS THE CENTRAL
LAKES. THIS WILL CAUSE THE FLOW TO BECOME MORE WESTERLY. SMALL
CRAFT HEADLINES MAY BE NEEDED AT THAT TIME. TILL THEN EXPECT
WEAK LAKE/LAND BREEZE CIRCULATIONS IN THE NEARSHORE. HIGH PRESSURE
WILL RETURN FOR THE SECOND HALF OF NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KOSARIK
SHORT TERM...DJB
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
935 AM EDT SAT MAY 9 2015
.SYNOPSIS...
A COLD FRONT OVER THE CENTRAL GREAT LAKES WILL STALL NEAR LAKE
ERIE BY SUNDAY. LOW PRESSURE DEVELOPING OVER THE PLAINS STATES
WILL TRACK ACROSS THE GREAT LAKES MONDAY AND THE ASSOCIATED COLD
FRONT WILL PUSH ACROSS THE AREA MONDAY NIGHT. COOLER WEATHER WILL
RETURN BY TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOTS GOING ON THIS MORNING BUT NONE OF IT ALL THAT SIGNIFICANT.
THE RIDGE ALOFT IS PROGGED TO CONTINUE TO BUILD TODAY...MAINLY
ACROSS NORTHEAST OHIO AND NORTHWEST PA. DISSIPATING SHOWERS ACROSS
NORTHWEST OHIO WILL CONTINUE TO DRY UP. THE MORNING SOUNDINGS ARE
PRETTY UNSTABLE BELOW 600 MB AND WIDELY SCATTERED SHOWERS HAVE
POPPED UP ACROSS NORTHEAST OHIO AND NORTHWEST PA. THIS WILL LIKELY
CONTINUE TO BE THE CASE UNTIL THE ATMOSPHERE GETS BETTER MIXED.
BELIEVE THESE STRAY SHOWERS WILL GO AWAY BY NOON.
THERE IS A LARGE AREA OF SHOWERS AND THUNDERSTORMS OVER THE
MISSISSIPPI VALLEY MOVING TOWARD THE LOWER OHIO VALLEY THAT COULD
INITIATE MORE CONVECTION AS THE OUTFLOW TRAVELS NORTHEAST THIS
AFTERNOON. THERE IS A FRONT DROPPING SOUTHEAST ACROSS THE
CENTRAL GREAT LAKES AND EXPECT MORE THUNDERSTORMS TO DEVELOP ALONG
THE FRONT. EVENTUALLY WE WILL GET SQUEEZED THIS AFTERNOON AND NEW
SHOWERS AND THUNDERSTORMS WILL DEVELOP. NOT SURE IF THE CURRENT
WORDING OF "LIKELY" IS THE BEST DESCRIPTOR. THE HEIGHTS ARE SO
HIGH JUST NOT VERY CONFIDENT OF HOW EXTENSIVE THE COVERAGE WILL
BE. WILL LEAVE THE FORECAST AS IS FOR NOW AND WILL CONTINUE TO TRY
TO REFINE THE FORECAST TODAY.
HIGHS IN THE 80S. THE BEST CHANCE FOR A RECORD HIGH MIGHT BE AT
ERIE PA (OLD RECORD 86 1880). ELSEWHERE MAYBE TOO MANY CLOUDS TO GET
QUITE AS WARM AS YESTERDAY...PERHAPS JUST A DEGREE OR TWO SHY OF
THE RECORDS WHICH ARE MOSTLY IN THE UPPER 80S?
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
EXPECT FIRST WAVE OF CONVECTION TO MOVE EAST OF THE AREA TOWARD
MIDNIGHT LOCAL...THEN A DRY PERIOD UNTIL THE SECOND WAVE OF
CONVECTION DEVELOPS SOMETIME SUNDAY AFTERNOON. MODELS NOT IN GOOD
AGREEMENT ON TIMING OR LOCATION. BASICALLY WENT WITH LIKELY POPS
AWAY FROM THE LAKESHORE LATE SUNDAY AFTERNOON AND EVENING. MODELS
CONTINUE TO BE IN REASONABLE AGREEMENT MOVING ANOTHER LOW PRESSURE
SYSTEM INTO THE CENTRAL LAKES MONDAY NIGHT...DRAGGING COLD FRONT
ACROSS THE FORECAST AREA. SO BEST CHANCE OF CONVECTION REMAINS
MONDAY AFTERNOON INTO THE OVERNIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THOSE PEOPLE WANTING COOLER WEATHER WILL GET THEIR WISH DURING THE
LONG TERM PERIOD. STRONG CANADIAN HIGH PRESSURE WILL BUILD OVER THE
REGION FROM THE NORTHWEST FOR THE SECOND HALF OF THE WORKWEEK.
THERE WILL BE A DISTINCT AIR MASS CHANGE WITH HIGHS STRUGGLING TO
REACH 60 ON WEDNESDAY. BY FRIDAY TEMPS WILL BE BACK CLOSE TO
NORMAL. WILL CONTINUE WITH A DRY FORECAST FOR THE ENTIRE THREE DAY
PERIOD BUT PRECIP COULD BE KNOCKING ON THE DOOR TO THE SOUTHWEST
FRIDAY NIGHT. HAVE USED A BLEND OF GUIDANCE TEMPS FOR THE PERIOD.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SOME RADAR RETURNS SHOWING UP ALONG THE I-75 CORRIDOR. MOST OF
THIS IS VERY LIGHT RAIN IF IT IS REACHING THE GROUND AT ALL. THE
LATEST HRRR SUGGESTS THIS ACTIVITY WILL MOVE OFF TO THE NNE AND
DISSIPATE THE NEXT COUPLE OF HOURS. STILL EXPECTING ANOTHER ROUND
OF SHOWERS AND STORMS LATER TODAY. BASED ON NEW GUIDANCE HAVE
SLOWED DOWN THE START AN HOUR OR TWO MOST AREAS. GIVEN LACK OF
FORCING AND UPPER SORT ANY STORMS THAT DO DEVELOP WITH BE OF THE
GARDEN VARIETY. THE PRECIP SHOULD QUICKLY END FROM WEST TO EAST
AFTER 00Z. LIGHT FLOW WILL BECOME S TO SW BY MIDDAY. SOME GUSTS
OVER 20 KNOTS ARE POSSIBLE LATER TODAY.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS THROUGH
MONDAY NIGHT.
&&
.MARINE...
MAINLY SOUTH TO SOUTHWEST FLOW UNDER 15 KNOTS IS EXPECTED ON THE
LAKE INTO MONDAY. A COLD FRONT WILL EVENTUALLY CROSS THE LAKE
SOMETIME EARLY TUESDAY AS LOW PRESSURE MOVES ACROSS THE CENTRAL
LAKES. THIS WILL CAUSE THE FLOW TO BECOME MORE WESTERLY. SMALL
CRAFT HEADLINES MAY BE NEEDED AT THAT TIME. TILL THEN EXPECT
WEAK LAKE/LAND BREEZE CIRCULATIONS IN THE NEARSHORE. HIGH PRESSURE
WILL RETURN FOR THE SECOND HALF OF NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK/DJB
NEAR TERM...KOSARIK/DJB
SHORT TERM...DJB
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
728 AM EDT SAT MAY 9 2015
.SYNOPSIS...
LOW PRESSURE OVER MICHIGAN WILL MOVE INTO NEW ENGLAND SUNDAY WITH
THE TRAILING FRONT STALLING NORTH OF THE FORECAST AREA. FRONT WILL
PUSH THROUGH AS A COLD FRONT MONDAY NIGHT AS WAVE OF LOW PRESSURE
TRACKS ACROSS THE CENTRAL LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A FEW STRAY SHOWERS COULD EFFECT NW OH EARLY THIS MORNING...AFTER
THAT SHOULD BE DRY UNTIL THIS AFTERNOON...SO TWEAKED HOURLY POPS
TO REFLECT THAT.
MORNING SHOULD BE RELATIVELY DRY AS LOW PRESSURE OVER MICHIGAN
CONTINUES TO MOVE AWAY FROM FORECAST AREA. EXPECT SCATTERED TSRA
TO DEVELOP THIS AFTERNOON. THIS AFTERNOON CAPES APPROACH 2000 J/KG
AND THE UPPER LEVEL RIDGE THAT HAS BEEN SHIELDING THE AREA WILL
SLIDE EAST...BUT NO TRIGGER THAT I CAN PIN POINT. GFS SEEMS TO BE
SUFFERING FROM CONVECTIVE FEEDBACK SO LEANED TOWARD THE 00Z ECMWF
FOR QPF.
AT THE SURFACE THE LOW PRESSURE SYSTEM OVER MICHIGAN WILL MOVE INTO
NEW ENGLAND BY DAYBREAK SUNDAY. AS THE LOW MOVES EAST THE TRAILING
COLD FRONT WILL STRETCH ACROSS THE CENTRAL LAKES JUST NORTH OF THE
FORECAST AREA AND STALL. OBVIOUSLY ENTIRE AREA WILL REMAIN IN THE
WARM SECTOR TODAY. FOR TEMPS WENT ABOVE GUIDANCE WITH TEMPS IN THE
MID TO UPPER 80S. DO EXPECT TEMPS TO BE A COUPLE OF DEGREES COOLER
THAN YESTERDAY WITH THE AFTERNOON CONVECTION. IT ALL DEPENDS ON
HOW MUCH CONVECTION DEVELOPS AND HOW SOON IT DEVELOPS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
EXPECT FIRST WAVE OF CONVECTION TO MOVE EAST OF THE AREA TOWARD
MIDNIGHT LOCAL...THEN A DRY PERIOD UNTIL THE SECOND WAVE OF
CONVECTION DEVELOPS SOMETIME SUNDAY AFTERNOON. MODELS NOT IN GOOD
AGREEMENT ON TIMING OR LOCATION. BASICALLY WENT WITH LIKELY POPS
AWAY FROM THE LAKESHORE LATE SUNDAY AFTERNOON AND EVENING. MODELS
CONTINUE TO BE IN REASONABLE AGREEMENT MOVING ANOTHER LOW PRESSURE
SYSTEM INTO THE CENTRAL LAKES MONDAY NIGHT...DRAGGING COLD FRONT
ACROSS THE FORECAST AREA. SO BEST CHANCE OF CONVECTION REMAINS
MONDAY AFTERNOON INTO THE OVERNIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THOSE PEOPLE WANTING COOLER WEATHER WILL GET THEIR WISH DURING THE
LONG TERM PERIOD. STRONG CANADIAN HIGH PRESSURE WILL BUILD OVER THE
REGION FROM THE NORTHWEST FOR THE SECOND HALF OF THE WORKWEEK.
THERE WILL BE A DISTINCT AIRMASS CHANGE WITH HIGHS STRUGGLING TO
REACH 60 ON WEDNESDAY. BY FRIDAY TEMPS WILL BE BACK CLOSE TO
NORMAL. WILL CONTINUE WITH A DRY FORECAST FOR THE ENTIRE THREE DAY
PERIOD BUT PRECIP COULD BE KNOCKING ON THE DOOR TO THE SOUTHWEST
FRIDAY NIGHT. HAVE USED A BLEND OF GUIDANCE TEMPS FOR THE PERIOD.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SOME RADAR RETURNS SHOWING UP ALONG THE I-75 CORRIDOR. MOST OF
THIS IS VERY LIGHT RAIN IF IT IS REACHING THE GROUND AT ALL. THE
LATEST HRRR SUGGESTS THIS ACTIVITY WILL MOVE OFF TO THE NNE AND
DISSIPATE THE NEXT COUPLE OF HOURS. STILL EXPECTING ANOTHER ROUND
OF SHOWERS AND STORMS LATER TODAY. BASED ON NEW GUIDANCE HAVE
SLOWED DOWN THE START AN HOUR OR TWO MOST AREAS. GIVEN LACK OF
FORCING AND UPPER SORT ANY STORMS THAT DO DEVELOP WITH BE OF THE
GARDEN VARIETY. THE PRECIP SHOULD QUICKLY END FROM WEST TO EAST
AFTER 00Z. LIGHT FLOW WILL BECOME S TO SW BY MIDDAY. SOME GUSTS
OVER 20 KNOTS ARE POSSIBLE LATER TODAY.
.OUTLOOK...NON VFR POSSIBLE IN SHOWERS AND THUNDERSTORMS THROUGH
MONDAY NIGHT.
&&
.MARINE...
MAINLY SOUTH TO SOUTHWEST FLOW UNDER 15 KNOTS IS EXPECTED ON THE
LAKE INTO MONDAY. A COLD FRONT WILL EVENTUALLY CROSS THE LAKE
SOMETIME EARLY TUESDAY AS LOW PRESSURE MOVES ACROSS THE CENTRAL
LAKES. THIS WILL CAUSE THE FLOW TO BECOME MORE WESTERLY. SMALL
CRAFT HEADLINES MAY BE NEEDED AT THAT TIME. TILL THEN EXPECT
WEAK LAKE/LAND BREEZE CIRCULATIONS IN THE NEARSHORE. HIGH PRESSURE
WILL RETURN FOR THE SECOND HALF OF NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DJB
NEAR TERM...DJB
SHORT TERM...DJB
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS TULSA OK
1244 AM CDT SAT MAY 9 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
BACK EDGE OF RAIN/THUNDER AT 06Z TAF VALID TIME VERY NEAR
TAF SITES KBVO KTUL KRVS KMLC. BACK EDGE RAIN/THUNDER TO
TAF SITES KXNA KFYV KROG KFSM AROUND 09Z. PERIOD VFR CEILINGS
HOWEVER MVFR/IFR FOG MAY FORM FROM HEAVY RAINFALL LATE TONIGHT
EARLY DAYLIGHT HOURS. NEXT ROUND OF SHOWERS/THUNDERSTORMS
LATE AFTERNOON AND EVENING HOURS.
&&
.PREV DISCUSSION... /ISSUED 645 PM CDT FRI MAY 8 2015/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
CENTRAL OK THUNDERSTORMS MOVING EAST ACROSS EASTERN OK AND
NORTHWEST AR OVERNIGHT. AFTER SEVERAL HOURS THUNDER WIDESPREAD
RESIDUAL SHOWERS...THEN RECHARGE AND MORE THUNDER SATURDAY.
PREV DISCUSSION... /ISSUED 253 PM CDT FRI MAY 8 2015/
DISCUSSION...
SIGNIFICANT FLOODING AND POTENTIAL SEVERE WEATHER CONCERNS ACROSS
EASTERN OKLAHOMA AND WESTERN ARKANSAS REMAIN ONGOING TODAY...AND
WILL PERSIST THROUGH THE WEEKEND.
AT PRESENT...A WARM FRONT IS EVIDENT IN SURFACE AND SATELLITE
OBSERVATIONS EXTENDING FROM SOUTHWEST OKLAHOMA...NORTHEASTWARD
INTO CENTRAL AND PARTS OF EAST CENTRAL OKLAHOMA...AND BACK
SOUTHEASTWARD THROUGH FAR SOUTHEAST OKLAHOMA. DESTABILIZATION IS
OCCURING TO THE SOUTH OF THE FRONT...WITH LOW TO MID 70S DEW
POINTS PREVALENT. 18Z SOUNDINGS FROM OUN AND FWD ARE INDICATIVE OF
A HIGHLY UNSTABLE ATMOSPHERE...AND MESOANALYSES SHOW A TONGUE OF
THIS INSTABILITY EXTENDING NORTHWARD INTO PORTIONS OF NORTHEAST
AND NORTH CENTRAL OKLAHOMA ROUGHLY BETWEEN THE INTERSTATE 35 AND
HIGHWAY 75 TO 69 CORRIDORS. AS SUCH...ONGOING ACTIVITY IN
SOUTHWEST OKLAHOMA /ASSOCIATED WITH AN UPPER LEVEL SPEED MAX/ MAY
HAVE A TENDENCY TO MOVE/SPREAD TO THE NORTHEAST TOWARD PARTS OF
EAST CENTRAL AND PERHAPS NORTHEAST OKLAHOMA AS OPPOSED TO SIMPLY
THE EAST NEAR THE RED RIVER. THE LOCAL WRF AND THE LATEST
INFORMATION FROM THE HRRR SUPPORT THIS SCENARIO...WITH ADDITIONAL
STORMS LIKELY TO MAKE A MID TO LATE EVENING RUN ALONG THE RED
RIVER IN RESPONSE TO AN INCREASE IN THE LOW LEVEL JET. THE OVERALL
TORNADO THREAT SHOULD BE FAIRLY LOW ACROSS MUCH OF THE FORECAST
AREA...ALTHOUGH A LOCALLY HIGHER THREAT WILL EXIST NEAR THE WARM
FRONT AND ALSO ACROSS FAR SOUTHEAST OKLAHOMA WITH THE INCREASE IN
THE LOW LEVEL JET.
WITH WELL ABOVE NORMAL PRECIPITABLE WATER VALUES AND HIGHLY
EFFICIENT RAINFALL PROCESSES LIKELY TO CONTINUE ACROSS THE
FORECAST AREA...SIGNIFICANT FLOODING CONCERNS WILL
PERSIST...ESPECIALLY IN AREAS THAT HAVE OVERLY WET ANTECEDENT
CONDITIONS. THROUGH THE NEXT 12 TO 18 HOURS...IT APPEARS THAT
SOUTHEAST OKLAHOMA WILL HAVE THE BEST CHANCE OF
FLOODING...ALTHOUGH IT IS BY NO MEANS ZERO IN OTHER PARTS OF
EASTERN OKLAHOMA AND WESTERN ARKANSAS.
AS HAS BEEN SAID A LOT IN THE LAST FEW DAYS...SATURDAY/S SEVERE
THREAT WILL BE VERY DEPENDENT ON WHAT HAPPENS LATER TONIGHT AND
INTO SATURDAY MORNING. STORMS COULD LINGER ACROSS PARTS OF
NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS INTO SATURDAY
MORNING...BEFORE MOVING OUT BY MID MORNING. ADDITIONAL
THUNDERSTORMS SHOULD DEVELOP TO THE WEST...AHEAD OF THE DRYLINE...
EARLY TO MID MORNING...AND BEGIN TO MOVE INTO SOUTHEAST OKLAHOMA
LATE MORNING TO EARLY AFTERNOON. THESE STORMS WILL SPREAD TO THE
EAST AND NORTHEAST FROM THERE. IF SUFFICIENT INSTABILITY CAN
DEVELOP BEHIND THE EARLY MORNING STORMS AND IN ADVANCE OF THE
LATER ROUND...A SEVERE THREAT WILL EXIST IN EASTERN OKLAHOMA
BEGINNING AS SOON AS EARLY AFTERNOON...ALTHOUGH MODEST DEEP LAYER
SHEAR COULD LIMIT THE SEVERITY UNTIL LATER IN THE DAY. A VEERED
LOW LEVEL JET LOOKS TO MOVE INTO PARTS OF EASTERN OKLAHOMA MID TO
LATE AFTERNOON WHICH WOULD LEAD TO AN INCREASE IN THE TORNADO
THREAT.
THE COLD FRONT AND DRYLINE WILL FINALLY MAKE A PUSH TOWARD THE
EAST AND SOUTHEAST LATE SATURDAY AND SATURDAY NIGHT...AS THE MAIN
UPPER LOW FINALLY EJECTS INTO THE CENTRAL PLAINS. THIS SHOULD
BRING ANOTHER CHANCE OF WIDESPREAD THUNDERSTORMS AND HEAVY
RAINFALL...WITH THIS SAME RISK PERSISTING INTO SUNDAY AND SUNDAY
NIGHT UNTIL THE BOUNDARIES FINALLY CLEAR THE REGION. STILL THINK
THE BEST CHANCE OF WIDESPREAD SEVERE WEATHER IN THE FORECAST AREA
MAY BE SUNDAY...ALTHOUGH THE IMPACT MAY NOT BE AS GREAT AS THE
POTENTIAL FOR LATER TODAY AND TOMORROW.
ON THE RAINFALL FRONT...A WIDESPREAD 3 TO 6 INCHES OF RAINFALL
SHOULD OCCUR BEFORE ALL IS SAID AND DONE MONDAY MORNING...WITH
LOCAL AMOUNTS APPROACHING 10 INCHES. WIDESPREAD RIVER FLOODING AND
FLASH FLOOD POTENTIAL MAY VERY WELL END UP BEING THE BIG STORY
FROM THIS EVENT.
EARLY NEXT WEEK THERE SHOULD BE A DAY OR TWO WHERE SURFACE HIGH
PRESSURE LEADS TO A COOL AND DRY PERIOD...BUT MOISTURE MAKES A
QUICK RETURN TOWARD THE MIDDLE PART OF NEXT WEEK...BRINGING MORE
THUNDERSTORMS AND RAINFALL TO THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 68 78 52 70 / 70 80 60 10
FSM 66 79 60 75 / 60 80 80 30
MLC 69 76 57 71 / 70 80 80 10
BVO 65 78 51 69 / 70 60 60 10
FYV 64 74 57 70 / 60 80 80 20
BYV 65 76 57 72 / 60 80 80 30
MKO 66 76 54 70 / 70 80 80 10
MIO 66 77 53 69 / 70 80 70 10
F10 67 76 54 70 / 70 80 80 10
HHW 68 78 62 75 / 60 80 80 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH UNTIL 7 AM MONDAY FOR OKZ049-OKZ053-OKZ054-
OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-
OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-
OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...FLASH FLOOD WATCH UNTIL 7 AM MONDAY FOR ARZ001-ARZ002-ARZ010-
ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...06
LONG TERM....18
AVIATION...21
AREA FORECAST DISCUSSION
NWS NORMAN OK
1201 AM CDT SAT MAY 9 2015
.DISCUSSION...
STORMS CONTINUE TO WEAKEN OVER SOUTHEASTERN OKLAHOMA. DO NOT
THINK ANY OF THESE STORMS WILL BE SEVERE FOR THE REST OF TONIGHT.
HOWEVER...ADDITIONAL ELEVATED THUNDERSTORMS MAY INCREASE IN
COVERAGE AND PERHAPS INTENSITY OVER THE NEXT SEVERAL HOURS IN
WESTERN NORTH TEXAS AS THE LOW LEVEL JET INCREASES. CANNOT
COMPLETELY RULE OUT SEVERE HAIL AND ADDITIONAL HEAVY RAINFALL WITH
THIS ACTIVITY IN WESTERN NORTH TEXAS. DAMAGING WIND AND TORNADO
THREAT REMAINS VERY LOW HOWEVER AS THE LOW LEVELS SHOULD REMAIN
STABLE.
LATEST HRRR RUNS HAVE BEEN CONSISTENT WITH DEVELOPING ANOTHER
ROUND OF STORMS SATURDAY MORNING INTO EARLY AFTERNOON...MAINLY IN
THE 6 AM TO 2 PM TIME FRAME...MOVING SOUTHWEST TO NORTHEAST. SOME
OF THESE STORMS MAY BE SEVERE WITH LARGE HAIL. ADDITIONAL HEAVY
RAINFALL MAY OCCUR AS WELL. THE TORNADO AND DAMAGING WIND THREAT
WITH THIS ACTIVITY SEEMS TO BE RATHER LOW.
SIGNFICANT SEVERE STORMS MAY FORM SATURDAY AFTERNOON AND EVENING
CAPABLE OF GIANT HAIL AND TORNADOES...THOUGH NOT SURE THIS WILL
OCCUR AS THE MORNING STORMS MAY SOMEWHAT STABILIZE THE ATMOSPHERE.
WILL CLOSELY MONITOR.
AVIATION DISCUSSION FOR THE 06Z TAFS IS BELOW.
MBS
&&
.AVIATION...
LOW CONFIDENCE CONTINUES WITH THE TAFS.
WIDESPREAD MVFR/IFR CONDITIONS WILL LIKELY FORM 08-18Z. KEPT
MENTION OF THESE CONDITIONS IN TAFS...THOUGH NOT COMPLETELY SURE
THESE LOWER CONDITIONS WILL OCCUR. CONDITIONS WILL LIKELY IMPROVE
TO VFR AT MOST SITES AFTER 18Z.
ADDITIONAL TSRA MAY OCCUR NEARLY ANY TIME AND ANYWHERE. KEPT VCTS
MENTION AT MANY SITES...MAINLY 12-18Z...THEN AFTER 21Z...AS
TWO ROUNDS OF TSRA MAY OCCUR ACROSS THE AREA. BRIEF VARIABLE
GUSTY WINDS AND MVFR OR LOWER CONDITIONS ARE POSSIBLE. STORM
COVERAGE AND LOCATIONS REMAIN VERY UNCERTAIN.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 77 63 75 / 10 70 50 50
HOBART OK 59 78 57 78 / 20 70 30 20
WICHITA FALLS TX 62 80 63 78 / 20 70 60 60
GAGE OK 59 78 51 74 / 20 70 20 10
PONCA CITY OK 63 77 63 76 / 10 70 60 40
DURANT OK 64 79 66 76 / 100 70 70 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLOOD WATCH THROUGH SUNDAY EVENING FOR OKZ006>008-011>013-
015>048-050>052.
TX...FLOOD WATCH THROUGH SUNDAY EVENING FOR TXZ083>090.
&&
$$
17
AREA FORECAST DISCUSSION
NWS MEDFORD OR
824 PM PDT SUN MAY 10 2015
.DISCUSSION...SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED LATE
THIS AFTERNOON ALONG A COLD FRONT AND AN AXIS OF INSTABILITY FROM
SOUTHERN SISKIYOU COUNTY NORTHEASTWARD TO KLAMATH AND NORTHWEST
LAKE COUNTIES. THE COLD FRONT IS CURRENTLY SHIFTING TO THE EAST OF
THE CASCADES AND WILL EXIT THE CWA OVERNIGHT INTO MONDAY MORNING.
OVERALL, EXPECT SHOWERS TO DECREASE IN COVERAGE ACROSS THE EAST
SIDE AS THE EVENING PROGRESSES, BUT STILL EXPECT ISOLATED SHOWERS
TO LINGER PAST MIDNIGHT. WEST OF THE CASCADES, THE REST OF THIS
EVENING SHOULD BE MAINLY DRY ASIDE FROM ISOLATED SHOWERS ALONG THE
IMMEDIATE COAST. AN UPPER LOW APPROACHING FROM THE PACIFIC WILL
WILL BRING MORE WIDESPREAD SHOWERS TO WEST SIDE AREAS ON MONDAY
WITH ISOLATED THUNDERSTORMS AGAIN FROM THE CASCADES TO THE EAST
SIDE. MONDAY WILL BE MUCH COOLER. MANY INLAND AREAS WILL HAVE
HIGH TEMPERATURES 15 TO 20 DEGREES LOWER THAN THEY WERE TODAY.
SPILDE
&&
.AVIATION...FOR THE 11/00Z TAF CYCLE...SHOWERS AND THUNDERSTORMS
WITH BRIEF MVFR CIGS/VIS WILL CONTINUE THIS EVENING FROM CENTRAL
SISKIYOU COUNTY INTO THE CASCADES AND PORTIONS OF THE EAST SIDE,
THEN DIMINISH OVERNIGHT. IFR CIGS AT THE COAST THIS EVENING WILL
LIFT TO MVFR TONIGHT AS A COLD FRONT MOVES THROUGH AND MIXES THINGS
UP. ELSEWHERE, CONDITIONS ARE EXPECTED TO BE MVFR OR BETTER THROUGH
MONDAY MORNING. AS AN UPPER LOW MOVES IN LATER MONDAY, SHOWERS WILL
REDEVELOP ON THE WEST SIDE WITH SHOWERS AND THUNDERSTORMS AGAIN EAST
OF THE CASCADES. CONDITIONS ARE EXPECTED TO BE VFR MONDAY EXCEPT FOR
OCCASIONAL MVFR CIGS/VIS IN SHOWERS. -WRIGHT
&&
.MARINE...UPDATED 145 PM PDT SUNDAY, MAY 10, 2015...A DRY COLD FRONT
MOVING THROUGH THE WATERS THIS AFTERNOON WILL CAUSE NORTH WINDS TO
INCREASE THROUGH EARLY MONDAY. THESE INCREASING NORTH WINDS WILL
RESULT IN STEEP SEAS FOR MOST OF THE WATERS BEYOND 10 MILES OF THE
COAST AND INNER WATERS SOUTH OF PORT ORFORD. THESE SMALL CRAFT
ADVISORY CONDITIONS ARE EXPECTED TO LINGER THROUGH MONDAY NIGHT.
SHOWERS ARE EXPECTED MONDAY EVENING THROUGH WEDNESDAY. WINDS AND
SEAS WILL DIMINISH ON TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY
LEVELS THROUGH THURSDAY. -SCHAAF
&&
.PREV DISCUSSION... /ISSUED 226 PM PDT SUN MAY 10 2015/
SHORT TERM...CURRENT VISIBLE IMAGE SHOWS CUMULUS ALREADY STARTING
TO BUILD UP ALONG THE CASCADES AND FROM THE SCOTT VALLEY TO THE
TRINITY ALPS AND AND SISKIYOUS IN NORTHERN CAL AND ARE MOVING
NORTHEAST. THE PAST SEVERAL RUNS OF THE HRRR MODEL (WHICH IS
UPDATED HOURLY) CONTINUES TO SHOW SOME CONVECTIVE SHOWERS IN THE
ABOVE MENTION AREAS IN ADDITION TO SOUTH THROUGH EASTERN JACKSON
COUNTY AND NORTHERN KLAMATH COUNTY. THE MODELS SUGGEST THERE`S
ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON
INTO THIS EVENING. THE 700 MB WINDS ARE FROM THE SOUTHWEST, SO
SHOWERS AND ISOLATED STORMS THAT DEVELOP WILL GENERALLY MOVE
NORTHEAST. ISOLATED STORMS WILL END THIS EVENING AS WE LOSE
DAYTIME HEATING, BUT INSTABILITY SHOWERS WILL CONTINUE OVERNIGHT
AS THE UPPER TROUGH CURRENTLY NEAR 45N/130W DIGS SOUTH TOWARDS THE
OREGON COAST.
THE UPPER TROUGH WILL EVOLVE INTO AN UPPER LOW AND THIS WILL BE
RESPONSIBLE FOR BRINGING MUCH COOLER TEMPERATURES...SCATTERED
SHOWERS JUST ABOUT ANYWHERE IN THE FORECAST AREA MONDAY AND TUESDAY.
IN ADDITION, ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF
THE CASCADES BOTH MONDAY AND TUESDAY AFTERNOON AND EARLY EVENING.
THE UPPER TROUGH WILL DIG SOUTH AND BECOME AND UPPER LOW MONDAY...
REACH THE OREGON COAST MONDAY AFTERNOON, THEN MOVE OVER THE AREA
MONDAY NIGHT INTO TUESDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE PLACEMENT OF THE UPPER LOW WHICH YIELDS HIGHER CONFIDENCE
WE`LL BE COOL AND WET FOR THE START OF NEXT WEEK. THE MODELS ALSO
SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES AND
PLENTY OF SHORTWAVES WILL MOVE OUT AHEAD OF THE UPPER LOW MONDAY
PROVIDING THE TRIGGER FOR ISOLATED STORMS TO FIRE UP.
THE UPPER LOW WILL MOVE OVERHEAD ON TUESDAY BRINGING COLD AIR ALOFT
WITH 500 MB TEMPERATURES BETWEEN -25 AND -28C. SHOWERS WILL OCCUR
JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE
AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED
TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER
SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE
HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. ISOLATED
THUNDERSTORMS REMAIN A CONCERN TUESDAY AFTERNOON ALONG AND EAST OF
THE CASCADES.
SHOWERS ARE EXPECTED TO GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW WEAKENS AND MOVES NORTH. HOWEVER THE NAM SHOW ANOTHER
SHORTWAVE ON THE HEALS OF THE UPPER TROUGH AND WE COULD SEE SHOWERS
INCREASE AGAIN EARLY WEDNESDAY MORNING. THE GFS IS SLOWER WITH THE
NEXT SHORTWAVE AND EC IS ALSO SLOWER AND WEAKER. EITHER ONE OF THESE
SOLUTIONS WILL RESULT IN A COOL AND UNSETTLED PATTERN ON WEDNESDAY.
-PETRUCELLI
LONG TERM...THURSDAY THROUGH SUNDAY...AN ACTIVE SHOWERY PATTERN
WITH A SLIGHT OF THUNDERSTORMS CONTINUES THROUGH THE EXTENDED
PERIOD AS AN UPPER LOW SHIFTS SOUTH AND THEN MOVES INLAND. ON
THURSDAY A STRONG UPPER LOW IS FORECAST TO SHIFT SOUTH OFF THE
CALIFORNIA COAST. SOUTHERLY MOISTURE IS FORECAST TO MOVE INTO THE
AREA AHEAD OF THIS LOW AND BRING SHOWERS ALONG WITH A SLIGHT
CHANCE OF THUNDERSTORMS ACROSS THE AREA. GIVEN THE SOUTH TO
SOUTHEAST FLOW ALOFT, HAVE EXTENDED THE SLIGHT RISK FOR
THUNDERSTORMS FURTHER WEST TO INCLUDE SOME WESTERN VALLEYS AS WELL
AS FROM THE CASCADES EAST. ON FRIDAY...THE UPPER LOW IS FORECAST
TO MOVE INTO SOUTHERN AND CENTRAL CALIFORNIA. MODELS CONTINUE TO
SHOW MOISTURE MOVING AROUND THE LOW INTO THE AREA ON FRIDAY WITH
INSTABILITY BRINGING A MIX OF SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS. ON FRIDAY, THE BEST CHANCE FOR ANY THUNDERSTORMS IS
EXPECTED FROM THE CASCADES EASTWARD ON FRIDAY BUT MAY EXTEND
FURTHER WEST ALONG THE WESTERN SLOPES OF THE CASCADES AND INTO
CENTRAL AND WESTERN SISKIYOU COUNTY. ON SATURDAY...AS THIS UPPER
LOW MOVES INLAND TO THE EAST- NORTHEAST...EXPECT SOME CONTINUED
SHOWER ACTIVITY OVER THE AREA. THE SLIGHT CHANCE OF THUNDERSTORMS
IS EXPECTED ONLY FOR FAR EASTERN ZONES IN LAKE AND MODOC COUNTIES.
LATE SATURDAY INTO SUNDAY...THE AREA MAY BE LOCATED BETWEEN THE
UPPER LOW WELL TO THE EAST AND A WEAK UPPER LOW OFF THE OREGON
COAST. DEPENDING ON THE POSITION OF THESE LOWS, MAY SEE SOME
CONTINUED SHOWERS OVER THE AREA. ALSO IF THE UPPER LOW OFF THE
COAST OF OREGON TRENDS STRONGER, MAY SEE ANOTHER CHANCE FOR
THUNDERSTORMS IN THE AREA ON SUNDAY. /CC
FIRE WEATHER...UPDATED 100 PM PDT SUNDAY, MAY 10, 2015...A WEAK
COLD FRONT WILL PERSIST OVER THE AREA THIS AFTERNOON AND EVENING
ALLOWING SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP FROM ABOUT
THE SHASTA AND SCOTT VALLEYS NORTHWARD TO THE SISKIYOUS AND INTO THE
CASCADES THIS AFTERNOON. STORMS ARE ALSO POSSIBLE ALONG THE WESTERN
SLOPES OF THE CASCADES AND INTO PORTIONS OF THE ROGUE VALLEY LATE
THIS AFTERNOON. THEN THIS EVENING...EXPECT ISOLATED THUNDERSTORMS
FROM THE CASCADES EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST
FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE
IN THESE AREAS AND MODELS CONTINUE TO SHOW INSTABILITY WITH THE
POTENTIAL FOR ISOLATED THUNDERSTORMS. STORMS SHOULD GENERALLY
PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE
AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM
SOUTHWEST TO NORTHEAST AT 10-20 KNOTS. THE STORMS WILL CAPABLE OF
GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY WEST TO
SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE
THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST
SIDE.
SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN
COVERAGE AND INTENSITY MONDAY MORNING THROUGH MONDAY EVENING AS AN
UPPER LOW MOVES INTO THE COAST. ISOLATED THUNDERSTORMS MIXED WITH
SHOWERS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND
EVENING, PRIMARILY FOR EASTERN SISKIYOU, MODOC, EASTERN KLAMATH
AND LAKE COUNTIES. THEN SHOWERS AND ISOLATED THUNDERSTORMS ARE
LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW
MOVES OVERHEAD. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM
11 PM THIS EVENING TO 11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
MAS/MAP/CC/TRW/BMS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1048 PM EDT SUN MAY 10 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL TURN NORTHEAST AND MOVE ACROSS EASTERN
NORTH CAROLINA TONIGHT INTO MONDAY...BEFORE MOVING OFF THE VIRGINIA
COAST. A COLD FRONT WILL CROSS OUR AREA ON TUESDAY. HIGH PRESSURE
WILL TRANSIT FROM THE GREAT LAKES WEDNESDAY TO OFF THE MID ATLANTIC
COAST BY NEXT WEEKEND AS MOISTURE FLOWS UP FROM THE GULF AND INTO
OUR AREA.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1030 PM EDT...ISOLD SRN PIEDMONT CONVECTION CONTINUES TO WANE
LATE THIS EVENING. THE LATEST HRRR RUNS ARE SUGGESTING LESS AND LESS
OVERNIGHT ACTIVITY AS BOUNDARY LAYER PARCELS STABILIZE. THE MAIN
EXCEPTION WILL BE OVER THE SW MTNS WHERE LIGHT UPSLOPE FLOW
TRIGGERING COULD CONTINUE TO PRODUCE ISOLD SHRA/TSRA DURING THE
EARLY MORNING HOURS. THE SW UPSLOPE FLOW BEGINS TO IMPROVE FURTHER
TOWARD DAYBREAK...BUT WITH ANY APPRECIABLLE CONVECTIVE COVERAGE
LIKELY RELEGATED UNTIL THE DAYLIGHT HOURS. SOME FOG DEVELOPMENT IS
LIKELY IN THE MTN VALLEYS AND AT LOCATIONS WHERE HEAVY RAIN FELL
TODAY...PARTICULARLY NEAR THE UPPER SAVANNAH RIVER REGION.
OTHERWISE...EXPECT PARTLY TO MOSTLY CLOUDY SKIES WITH SEVERAL RH
LAYERS LINGERING IN PROFILES...AND MIN TEMPS AROUND 10 DEGREES ABOVE
CLIMO OVERNIGHT.
MONDAY...500 MB HEIGHTS WILL BEGIN TO FALL ATOP THE CWFA...AS A
SLOWLY PHASING TROUGH EJECTS OUT INTO THE PLAINS. THE BOUNDARY LAYER
WILL BE QUITE MOIST...WITH DEWPOINTS GENERALLY IN THE MID 60S ACROSS
THE PIEDMONT...WHILE TEMPS WARM BACK INTO THE MID TO UPPER 80S. FCST
SOUNDINGS SHOW STRONG SBCAPE ON THE ORDER OF 1500 TO 2500 J/KG.
SHEAR WILL REMAIN VERY WEAK...AND DOWNBURST POTENTIAL LOOKS MUTED
GIVEN WET-BULB ZERO HEIGHTS OVER 10 KFT. SO EXPECT OVERALL BETTER
TSTM COVERAGE ACRS THE AREA (40-60 POP)...BUT SEVERE THREAT STILL
LOOKS MARGINAL. WILL PROBABLY SEE A FEW MARGINALLY SEVERE PULSE
STORMS GIVEN THE GOOD INSTABILITY. THERE WILL BE AN ISOLD FLASH
FLOOD THREAT AS WELL...AS STORMS WILL BE SLOW MOVING AND EFFICIENT
RAIN PRODUCERS IN THE MOIST ENVIRONMENT.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 150 PM SUNDAY...SHORT WAVE CROSSES THE AREA MONDAY NITE BEFORE
A DAMPENING UPPER TROF CROSSES ON TUE. AT THE SFC...THE ASSOCIATED
COLD FRONT CROSSES THE AREA ON TUESDAY. AHEAD OF THE FRONT...EXPECT
SOME LINGERING CONVECTION MONDAY NITE...THEN REDEVELOPING ON
TUE...MAINLY ALONG AND SOUTH OF I-85 WHERE BEST MOISTURE AND
INSTABILITY REMAIN. BULK SHEAR INCREASES SIGNIFICANTLY TUE AS WINDS
INCREASE WITH THE FRONT AND UPPER TROF. HOWEVER...INSTABILITY WILL
REMAIN WEAK AS INDICATED ON EVEN THE MOST ROBUST GUIDANCE.
THEREFORE...ONLY EXPECT THUNDER TO DEVELOP ALONG AND SOUTH OF I-85
WITH ONLY A VERY LOW SVR THREAT AT BEST. TEMPS REMAIN AROUND 10
DEGREES ABOVE NORMAL.
UPPER RIDGING BUILDS OVER THE CENTRAL CONUS WED WITH NWLY FLOW
DEVELOPING OVER THE AREA AS THE UPPER TROF MOVES EAST. AT THE SFC...
DRY AND COOLER HIGH PRESSURE BEGINS TO BUILD IN FROM THE NW. EXPECT
DRY CONDITIONS WITH TEMPS FROM NEAR NORMAL TO 5 DEGREES ABOVE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 255 PM SUNDAY...UPPER RIDGE BUILDS INTO THE AREA THU...THEN IS
KNOCKED DOWN FRI BY A SHORT WAVE MOVING OVER THE AREA. RIDGING
RETURNS FOR SAT AND SUN...ALTHOUGH A SHORT WAVE WILL MOVE THRU THE
RIDGE AND ACROSS THE AREA SUN.
DRY HIGH PRESSURE MOVES ACROSS THE AREA THU THEN OFF SHORE FRI. SLY
LOW LEVEL FLOW DEVELOPS FRI IN THE FLOW AROUND THE HIGH AND A LOW
PRESSURE MOVING ALONG A DEVELOPING WARM FRONT NEAR THE OH VALLEY.
THE MOIST SLY FLOW CONTINUES SAT. EXPECT INCREASING CHC OF SHOWERS
AND THUNDERSTORMS EACH DAY. THE MOIST AND UNSTABLE AIR MASS REMAINS
OVER THE AREA SUN WITH A CONTINUED CHC OF CONVECTION...BUT COULD
HAVE MORE OF A DIURNAL TREND. TEMPS START OUT NEAR NORMAL THU...
FALL A LITTLE BELOW NORMAL FRI...RETURN TO NEAR NORMAL SAT THEN BACK
ABOVE NORMAL SUN.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AT KCLT...NEARLY ALL LOWER LEVEL VFR CLOUDS HAVE SCATTERED ALONG THE
WRN PERIPHERY OF THE ANA REMNANTS THIS EVENING. ANY CIGS THROUGH THE
NIGHT SHOULD THUS BE HIGHER LEVEL VFR AT 6 TO 8 KFT OR HIGHER AS
VARIOUS NARROW MOIST LAYERS PIVOT TOWARD THE PIEDMONT. NE FLOW WILL
SLACKEN WITH TIME AND TOGGLE SW BY MID MORNING MONDAY. CONVECTIVE
CUMULUS WILL REDEVELOP QUICKLY THROUGH THE DAY...WITH SCATTERED
THUNDERSTORMS DEVELOPING FROM THE WEST THROUGH THE AFTN HOURS ALONG
WITH IMPROVING SW FLOW.
ELSEWHERE...MID TO LATE EVENING ISOLD CONVECTION SHOULD REMAIN
MAINLY S OF KAND AND OVER THE FAR SW MTNS...WITH ANY OVERNIGHT
THREAT TOO ISOLD TO MENTION IN THE TAF. EXPECT SCT TO BKN VFR CLOUD
LAYERS THROUGHOUT...WITH LIGHT FOG OVERNIGHT AT KAVL IN THE FRENCH
BROAD VALLEY AND NEAR KAND. THE SW MTN VALLEYS WILL SEE FOGGIER
CONDITIONS. LIGHT AND VARIABLE WINDS WILL START OFF SW ON MONDAY
MORNING AND INCREASE THROUGH THE DAY. EXPECT SCATTERED THUNDERSTORM
COVERAGE TO DEVELOP FROM THE WEST THROUGH THE AFTN HOURS...WITH THE
BEST CHANCE AT KAVL...BUT WITH PROB30 WARRANTED AT THE FOOTHILL
SITES AS WELL AFTER 18Z OR 19Z.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING
ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE IN ON
WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE SOUTH...POSSIBLY
ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA LATE IN THE WEEK.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-00Z
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% MED 79% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...ARK/HG
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARK/HG
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
320 PM CDT SAT MAY 9 2015
.DISCUSSION...SURFACE ANALYSIS THIS AFTERNOON PLACES A QUASI-
STATIONARY BOUNDARY OVER PORTIONS OF SOUTHERN MISSOURI AND BACK
INTO OKLAHOMA AND PORTIONS OF THE TEXAS/OKLAHOMA PANHANDLE.
SHOWERS AND THUNDERSTORM COVERAGE HAS DECREASED IN COVERAGE ACROSS
THE MID SOUTH THIS AFTERNOON AS THE ATMOSPHERE HAS STABILIZED
SOMEWHAT. A CLUSTER OF SHOWERS ARE LOCATED ACROSS PORTIONS OF
NORTH CENTRAL AND NORTHEAST ARKANSAS AS OF LATE THIS AFTERNOON.
TEMPERATURES AS OF 3 PM CDT ARE IN THE UPPER 70S TO LOWER 80S AT
MOST LOCATIONS.
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILES OVER THE PAST FEW
HOURS HAVE INDICATED ANOTHER MESOSCALE CONVECTIVE SYSTEM /MCS/ HAS
DEVELOPED ACROSS OKLAHOMA AND THE RED RIVER VALLEY OF TEXAS.
WRF/GFS/ECMWF MODELS INDICATE THIS ACTIVITY SHOULD REMAIN MAINLY
WEST OF THE FORECAST AREA THIS EVENING. INTERESTINGLY ENOUGH...THE
19Z HRRR INDICATES CONVECTIVE ACTIVITY OVER NORTHEAST
TEXAS/EASTERN OKLAHOMA...AND SOUTHWEST ARKANSAS MAY SPREAD INTO
PORTIONS OF THE MID SOUTH ALONG AND WEST OF THE RIVER BY EARLY TO
MIDDLE EVENING. THIS HIGH RESOLUTION MODEL/S OUTPUT MAY BE TRYING
TO SUGGEST A COLD POOL DEVELOPING UPSTREAM AND BRINGING THE
CONVECTION INTO THE FORECAST AREA. WILL GO WITH CHANCE POPS ALONG
AND WEST OF THE MISSISSIPPI RIVER TONIGHT. EVENING SHIFT WILL
MONITOR MESOSCALE TRENDS AND ADJUST FORECAST AS NECESSARY
ESPECIALLY IF THE OUTLYING HRRR ENDS UP BEING THE CORRECT SHORT
TERM FORECAST SOLUTION.
SHORT TERM MODELS INDICATE SOUTHWEST FLOW ALOFT WILL REMAIN IN
PLACE ACROSS THE MID SOUTH ON SUNDAY WITH MOST IF NOT ALL SHOWERS
AND THUNDERSTORMS OCCURING UPSTREAM OF THE MID SOUTH.
CONSEQUENTLY...HAVE KEPT POPS ISOLATED AT BEST DURING THE DAY WITH
THE EXCEPTION OF EXTREME NORTHEAST MISSISSIPPI. ADDITIONAL SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND SPREAD INTO THE MID SOUTH
SUNDAY NIGHT INTO MONDAY AS A COLD FRONT DROPS INTO THE MID SOUTH.
THE BEST UPPER LEVEL FORCING AND FAVORABLE WINDS WILL MOVE
NORTHEAST OF THE FORECAST AREA BY MONDAY. SUFFICIENT
INSTABILITY...0-6 KM BULK SHEAR AND THE APPROACHING FRONT MAY BE
ENOUGH TO PRODUCE A CONDITIONAL THREAT FOR A FEW STRONG TO
PERHAPS SEVERE THUNDERSTORMS ACROSS THE MID SOUTH LATE SUNDAY
NIGHT INTO MONDAY.
THIS FRONT IS EXPECTED TO PUSH SOUTH OF THE FORECAST AREA BY
TUESDAY AFTERNOON/TUESDAY NIGHT AND BRING MAINLY RAIN FREE WEATHER
THROUGH WEDNESDAY NIGHT. SHOWER/THUNDERSTORM CHANCES WILL RETURN
LATE NEXT WEEK AS THE FRONT RETURNS BACK NORTH ACROSS THE MID
SOUTH.
CJC
&&
.AVIATION...
18Z TAFS
BEST EFFORT AT TIMING THE NEXT ROUND OF SHOWERS HAS THEM ARRIVING
IN THE VICINITY OF MEM AROUND 19Z...JBR AROUND 20Z AND MKL AROUND
22Z. ADDITIONAL DEVELOPMENT AHEAD OF THE LINE IS POSSIBLE...AS
WELL AS DEVELOPMENT OF THUNDERSTORMS...BUT ANY ATTEMPT AT
PREDICTING THAT WOULD BE NOTHING MORE THAN A GUESS. WILL HANDEL
ANY NEW DEVELOPMENT AND THUNDER WITH AMENDMENTS. STORMS WILL
GRADUALLY TAPER OFF AFTER SUNSET AREA WIDE. TUP WILL CONTINUE TO
HAVE ONLY LITE RAIN SHOWERS FOR THE REMAINDER OF THE AFTERNOON.
VFR CONDS SHOULD PREVAIL MOST OF THE OVERNIGHT HOURS...AND THROUGH
THE END OF THE FORECAST PERIOD.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1023 PM CDT SUN MAY 10 2015
.UPDATE...
SCATTERED SHOWERS /WITH AN ISOLATED EMBEDDED THUNDERSTORM OR TWO/
CONTINUE TO STREAM ACROSS THE REGION THIS EVENING AS WARM...MOIST
AIR FLOWS INTO A LINE OF THUNDERSTORMS MOVING EAST ACROSS CENTRAL
TEXAS. CONVECTIVE ACTIVITY ACROSS SOUTHEAST TEXAS HAS BEEN LARGELY
SUPPRESSED TODAY /21Z SOUNDING OUT OF COLLEGE STATION SHOWING A
CAPPING INVERSION AROUND 700 MB/... BUT HAVE STARTED TO SEE AN
INCREASE IN COVERAGE OVER THE PAST FEW HOURS WITH THE OVERHEAD LOW
LEVEL JET CARRYING A 925 MB VORTICITY MAXIMA ACROSS THE REGION
FROM THE GULF.
HIGH RESOLUTION GUIDANCE CONTINUES TO WANT TO BRING THE
AFOREMENTIONED LINE OF SHOWERS AND THUNDERSTORMS INTO THE
NORTHERN REACHES OF THE FORECAST AREA OVERNIGHT... BUT SEEING
SOMEWHAT OF A SLOWER TREND IN LATEST ITERATIONS. NOT TO BE
OUTDONE... INCOMING NAM12 GUIDANCE HAS COMPLETELY BACKED OFF ON
PRECIPITATION FOR SOUTHEAST TEXAS OVERNIGHT AND THIS INTRODUCES
SOME UNCERTAINTY INTO HOW TONIGHT WILL UNFOLD. DESPITE THIS...
WITH AMPLE LOW LEVEL MOISTURE IN PLACE AND WATER VAPOR IMAGERY
SHOWING THE APPROACH OF A SHORTWAVE FROM NEAR LAREDO...
MAINTAINING CHANCE TO LIKELY POPS FOR A GOOD PORTION OF THE AREA
OVERNIGHT. 00Z EVENING SOUNDINGS FROM CORPUS CHRISTI...LAKE
CHARLES...FORT WORTH... AND SHREVEPORT ALL SHOWED PRECIPITABLE
WATER VALUES GREATER THAN 1.4 INCHES... AND THESE HIGHER VALUES
INCREASE THE CONCERN FOR LOCALLY HEAVY RAINFALL WITH ANY ACTIVITY
THAT REACHES THE AREA OVERNIGHT. WITH SOME MODEST FORECAST SHEAR
AND INSTABILITY IN PLACE... CAN/T RULE OUT AN ISOLATED STRONGER
STORM AS WELL WITH THIS ACTIVITY.
HUFFMAN
&&
.PREV DISCUSSION... /ISSUED 614 PM CDT SUN MAY 10 2015/
DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
AVIATION...
STREAMER SHOWERS WILL CONTINUE TO DEVELOP FOR THE NEXT HOUR OR SO
AS A WEAK DISTURBANCE MOVES THROUGH SE TX. THERE SHOULD BE A BREAK
IN THE PRECIP FROM ABOUT 03Z TO ABOUT 09Z. CONFIDENCE IS
LOW...BUT AFTER 09Z...FEEL A LINE OF SHRA/TSRA OVER NORTH TEXAS
WILL SAG SOUTH AND AFFECT KCLL/KUTS BETWEEN 09-10Z. THE LINE WILL
CONTINUE TO DRIFT SOUTH AND WILL AFFECT KCXO BY 12Z. THE GFS/NAM
AND ECMWF ALL SHOW THE LINE WEAKENING BEFORE REACHING KIAH. WILL
BE MAKING SOME ADJUSTMENTS TO THE TAFS AT 03Z IF TIMING CAN BE
NAILED DOWN. GLOBAL MODELS IN BETTER AGREEMENT WITH A SECOND
DISTURBANCE MOVING ACROSS SE TX LATE MONDAY AFTN. PW VALUES WILL
APPROACH 2.00 INCHES WITH K INDEX VALUES NEAR 40. TOMORROW AFTN
LOOKS STORMY. 43
PREV DISCUSSION... /ISSUED 400 PM CDT SUN MAY 10 2015/
DISCUSSION...
ALL EYES ARE UPON CENTRAL TEXAS WHERE SPC HAS MODERATE RISK OF
SEVERE STORMS AND THERE HAS ALREADY BEEN ONE TORNADIC STORM TO
PUSH THROUGH DENTON TX. SFC ANALYSIS OVER SE TX HAS TYPICAL WARM
SECTOR AIRMASS WITH GUSTY SE WINDS AND DEWPOINTS IN THE LOW 70S.
WATER VAPOR IMAGERY SHOWS UPPER LOW OVER C PLAINS WITH ELONGATED
TROUGH AXIS STRETCHING BACK INTO THE S ROCKIES AS EXPECTED
YESTERDAY. UPPER AIR ANALYSIS SHOWS JET STREAK COMING OUT OF
MEXICO WHICH LATEST RAP ANALYSES HAVE OVER S TX AND JUST STARTING
TO REACH SE TX. JET STREAK SHOULD MOVE OVER THE AREA BY 03Z
TONIGHT SO THINK ANY CAPPING MAY ERODED BY LARGE SCALE ASCENT.
LATEST HRRR RUNS HAS CONVECTION NOW OVER C TX FORMING A SQUALL
LINE AND PUSHING INTO THE BRAZOS VALLEY AFTER MIDNIGHT TO 3AM.
THIS EVOLUTION INTO SOME BOWING SEGMENTS SUPPORTS SPC
ENHANCED/SLIGHT RISK OF SEVERE FOR TONIGHT. GIVEN
SHEAR/INSTABILITY PARAMETERS FOR TONIGHT...THINK THIS KIND OF
CONVECTION WILL CERTAINLY BE POSSIBLE.
MONDAY LOOKS LIKE THERE WILL BE PLENTY OF RECOVERY IN THE AIRMASS
FOR IT TO DESTABILIZE WITH MODERATE TO HIGH CAPE BY THE AFTERNOON.
DEEP LAYER SHEAR SEEMS TO WEAKEN BUT LOW LEVEL WIND FIELDS LOOK
MUCH LESS THAN THE LAST COUPLE OF DAYS. A FRONTAL BOUNDARY DOES
PUSH INTO N TX WHICH MAY SLACKEN THE PRESSURE GRADIENT ACROSS THE
AREA. FRONT MAY BE THE FOCUS FOR SOME SEVERE STORMS WITH HEAVY
RAINFALL FOR NORTHERN PORTIONS OF THE AREA. TROUBLE PART OF THE
FORECAST IS THAT MODELS ARE NOT ALL THAT AGGRESSIVE WITH PRECIP
MONDAY DESPITE A MUCH WEAKER CAP AND FAVORABLE UPPER LEVEL
PARAMETERS. NOT ONLY THAT PRECIP WATER VALUES INCREASE TO AROUND
1.8 INCHES AND THEN OVERNIGHT AT 06Z TUE GFS SHOWS 2 INCH PRECIP
WATER VALUES. THIS IS JUST AS A SHORT WAVE TROUGH MOVES OVER THE
REGION. MODELS CONTINUE TO HIT HILL COUNTRY AND S TX TO THE
COASTAL PLAIN WITH QUITE A BIT OF PRECIP WHILE PRECIP TOTALS FOR
SE TX REMAIN SOMEWHAT LOW GIVEN THE SITUATION. ONE OF THE FEW
MODELS THAT DOES PRODUCE QUITE A BIT OF PRECIP OVER THE AREA IS
THE 12Z WRF-ARW WHICH BRINGS A SQUALL LINE INTO THE AREA FROM S TX
CONSISTENT WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. OVERALL
KEPT POPS ON THE HIGH SIDE BUT PINNING DOWN THE DETAILS IS STILL A
CHALLENGE. WPC SEEMS TO AGREE WITH HEAVY RAINFALL THREAT AS MOST
OF THE AREA MON/TUE IS IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
LOOKING AT 3HR FFG VALUES...NEED A GOOD 4-5 INCHES OF RAIN IN A 3
HR PERIOD TO GET FLASH FLOODING. CAN HOLD OFF ON ANY FLOOD WATCH
AND SEE WHAT HAPPENS WITH FIRST COUPLE ROUNDS OF PRECIP. THIS WILL
HELP DETERMINE THE NEED FOR A WATCH GIVEN THE UNCERTAINTY IN THE
FORECAST.
BEYOND TUE IT LOOKS LIKE LATE WED/THUR MAY BE ANOTHER ROUND FOR
HEAVY RAINFALL. AGAIN THE FORECAST WILL KEEP HIGH RAIN CHANCE
GOING THROUGH THUR AND THEN TAPER OFF FOR THE REST OF THE WEEK.
THE SET UP FOR THURSDAY IS VERY SIMILAR WITH A SHORT WAVE TROUGH
MOVING ACROSS THE AREA. BIG DIFFERENCE IS THAT THE ECMWF SEEMS TO
HAVE THIS WAVE COMING ACROSS WED AFTERNOON WITH THE GFS HAVING TWO
WEAK WAVES...ONE WED AFTERNOON AND ANOTHER BY 12Z THUR. GOING INTO
THE END OF THE WEEK...UPPER LEVEL RIDGING DEVELOPS OVER TX AND
SHOULD SUPPORT LOWER POPS AND A DRY FORECAST. THIS MAY ALSO ALLOW
FOR MAX TEMPS IN THE UPPER 80S.
39
MARINE...
MODERATE TO STRONG SOUTHEAST WINDS AND ELEVATED SEAS ARE EXPECTED
TO CONTINUE OVER THE BAYS AND COASTAL WATERS TONIGHT AS THE
PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA. A WEAK FRONTAL
BOUNDARY IS STILL EXPECTED TO EDGE INTO THE NORTHERN PARTS OF
SOUTHEAST TEXAS LATE TONIGHT AND ON INTO EARLY MONDAY MORNING.
THIS FRONT WILL HELP TO WEAKEN THE GRADIENT AND ALLOW FOR
DECREASED WINDS AND SEAS FOR THE FIRST PART OF THE WEEK. AS THE
FRONT SLOWLY WASHES OUT...ONSHORE WINDS ARE EXPECTED TO SLOWLY
INCREASE DURING THE LATTER PART OF THE WEEK AND ON INTO NEXT
WEEKEND.
THE PERSISTENT ONSHORE WINDS CONTINUE TO SUPPORT STRONG RIP
CURRENTS AND THE POSSIBILITY OF ELEVATED TIDES. LEVELS COULD
APPROACH 3 FEET FOR LOCATIONS IN AND AROUND THE HOUSTON SHIP
CHANNEL AND ALONG THE GULF FACING BEACHES OF THE BOLIVAR PENINSULA
THIS AFTERNOON AND THIS EVENING. WAVE RUN-UP HAS THE POTENTIAL TO
BE A PROBLEM FOR LOW LYING AREAS ALONG THE BOLIVAR PENINSULA. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 84 68 76 68 / 50 60 80 70 60
HOUSTON (IAH) 75 85 70 81 70 / 30 60 70 70 40
GALVESTON (GLS) 77 82 75 80 74 / 20 50 60 60 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT MONDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...14
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
614 PM CDT SUN MAY 10 2015
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...
STREAMER SHOWERS WILL CONTINUE TO DEVELOP FOR THE NEXT HOUR OR SO
AS A WEAK DISTURBANCE MOVES THROUGH SE TX. THERE SHOULD BE A BREAK
IN THE PRECIP FROM ABOUT 03Z TO ABOUT 09Z. CONFIDENCE IS
LOW...BUT AFTER 09Z...FEEL A LINE OF SHRA/TSRA OVER NORTH TEXAS
WILL SAG SOUTH AND AFFECT KCLL/KUTS BETWEEN 09-10Z. THE LINE WILL
CONTINUE TO DRIFT SOUTH AND WILL AFFECT KCXO BY 12Z. THE GFS/NAM
AND ECMWF ALL SHOW THE LINE WEAKENING BEFORE REACHING KIAH. WILL
BE MAKING SOME ADJUSTMENTS TO THE TAFS AT 03Z IF TIMING CAN BE
NAILED DOWN. GLOBAL MODELS IN BETTER AGREEMENT WITH A SECOND
DISTURBANCE MOVING ACROSS SE TX LATE MONDAY AFTN. PW VALUES WILL
APPROACH 2.00 INCHES WITH K INDEX VALUES NEAR 40. TOMORROW AFTN
LOOKS STORMY. 43
&&
.PREV DISCUSSION... /ISSUED 400 PM CDT SUN MAY 10 2015/
DISCUSSION...
ALL EYES ARE UPON CENTRAL TEXAS WHERE SPC HAS MODERATE RISK OF
SEVERE STORMS AND THERE HAS ALREADY BEEN ONE TORNADIC STORM TO
PUSH THROUGH DENTON TX. SFC ANALYSIS OVER SE TX HAS TYPICAL WARM
SECTOR AIRMASS WITH GUSTY SE WINDS AND DEWPOINTS IN THE LOW 70S.
WATER VAPOR IMAGERY SHOWS UPPER LOW OVER C PLAINS WITH ELONGATED
TROUGH AXIS STRETCHING BACK INTO THE S ROCKIES AS EXPECTED
YESTERDAY. UPPER AIR ANALYSIS SHOWS JET STREAK COMING OUT OF
MEXICO WHICH LATEST RAP ANALYSES HAVE OVER S TX AND JUST STARTING
TO REACH SE TX. JET STREAK SHOULD MOVE OVER THE AREA BY 03Z
TONIGHT SO THINK ANY CAPPING MAY ERODED BY LARGE SCALE ASCENT.
LATEST HRRR RUNS HAS CONVECTION NOW OVER C TX FORMING A SQUALL
LINE AND PUSHING INTO THE BRAZOS VALLEY AFTER MIDNIGHT TO 3AM.
THIS EVOLUTION INTO SOME BOWING SEGMENTS SUPPORTS SPC
ENHANCED/SLIGHT RISK OF SEVERE FOR TONIGHT. GIVEN
SHEAR/INSTABILITY PARAMETERS FOR TONIGHT...THINK THIS KIND OF
CONVECTION WILL CERTAINLY BE POSSIBLE.
MONDAY LOOKS LIKE THERE WILL BE PLENTY OF RECOVERY IN THE AIRMASS
FOR IT TO DESTABILIZE WITH MODERATE TO HIGH CAPE BY THE AFTERNOON.
DEEP LAYER SHEAR SEEMS TO WEAKEN BUT LOW LEVEL WIND FIELDS LOOK
MUCH LESS THAN THE LAST COUPLE OF DAYS. A FRONTAL BOUNDARY DOES
PUSH INTO N TX WHICH MAY SLACKEN THE PRESSURE GRADIENT ACROSS THE
AREA. FRONT MAY BE THE FOCUS FOR SOME SEVERE STORMS WITH HEAVY
RAINFALL FOR NORTHERN PORTIONS OF THE AREA. TROUBLE PART OF THE
FORECAST IS THAT MODELS ARE NOT ALL THAT AGGRESSIVE WITH PRECIP
MONDAY DESPITE A MUCH WEAKER CAP AND FAVORABLE UPPER LEVEL
PARAMETERS. NOT ONLY THAT PRECIP WATER VALUES INCREASE TO AROUND
1.8 INCHES AND THEN OVERNIGHT AT 06Z TUE GFS SHOWS 2 INCH PRECIP
WATER VALUES. THIS IS JUST AS A SHORT WAVE TROUGH MOVES OVER THE
REGION. MODELS CONTINUE TO HIT HILL COUNTRY AND S TX TO THE
COASTAL PLAIN WITH QUITE A BIT OF PRECIP WHILE PRECIP TOTALS FOR
SE TX REMAIN SOMEWHAT LOW GIVEN THE SITUATION. ONE OF THE FEW
MODELS THAT DOES PRODUCE QUITE A BIT OF PRECIP OVER THE AREA IS
THE 12Z WRF-ARW WHICH BRINGS A SQUALL LINE INTO THE AREA FROM S TX
CONSISTENT WITH UPPER LEVEL FORCING FROM THE SHORTWAVE. OVERALL
KEPT POPS ON THE HIGH SIDE BUT PINNING DOWN THE DETAILS IS STILL A
CHALLENGE. WPC SEEMS TO AGREE WITH HEAVY RAINFALL THREAT AS MOST
OF THE AREA MON/TUE IS IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
LOOKING AT 3HR FFG VALUES...NEED A GOOD 4-5 INCHES OF RAIN IN A 3
HR PERIOD TO GET FLASH FLOODING. CAN HOLD OFF ON ANY FLOOD WATCH
AND SEE WHAT HAPPENS WITH FIRST COUPLE ROUNDS OF PRECIP. THIS WILL
HELP DETERMINE THE NEED FOR A WATCH GIVEN THE UNCERTAINTY IN THE
FORECAST.
BEYOND TUE IT LOOKS LIKE LATE WED/THUR MAY BE ANOTHER ROUND FOR
HEAVY RAINFALL. AGAIN THE FORECAST WILL KEEP HIGH RAIN CHANCE
GOING THROUGH THUR AND THEN TAPER OFF FOR THE REST OF THE WEEK.
THE SET UP FOR THURSDAY IS VERY SIMILAR WITH A SHORT WAVE TROUGH
MOVING ACROSS THE AREA. BIG DIFFERENCE IS THAT THE ECMWF SEEMS TO
HAVE THIS WAVE COMING ACROSS WED AFTERNOON WITH THE GFS HAVING TWO
WEAK WAVES...ONE WED AFTERNOON AND ANOTHER BY 12Z THUR. GOING INTO
THE END OF THE WEEK...UPPER LEVEL RIDGING DEVELOPS OVER TX AND
SHOULD SUPPORT LOWER POPS AND A DRY FORECAST. THIS MAY ALSO ALLOW
FOR MAX TEMPS IN THE UPPER 80S.
39
MARINE...
MODERATE TO STRONG SOUTHEAST WINDS AND ELEVATED SEAS ARE EXPECTED
TO CONTINUE OVER THE BAYS AND COASTAL WATERS TONIGHT AS THE
PRESSURE GRADIENT REMAINS TIGHT ACROSS THE AREA. A WEAK FRONTAL
BOUNDARY IS STILL EXPECTED TO EDGE INTO THE NORTHERN PARTS OF
SOUTHEAST TEXAS LATE TONIGHT AND ON INTO EARLY MONDAY MORNING.
THIS FRONT WILL HELP TO WEAKEN THE GRADIENT AND ALLOW FOR
DECREASED WINDS AND SEAS FOR THE FIRST PART OF THE WEEK. AS THE
FRONT SLOWLY WASHES OUT...ONSHORE WINDS ARE EXPECTED TO SLOWLY
INCREASE DURING THE LATTER PART OF THE WEEK AND ON INTO NEXT
WEEKEND.
THE PERSISTENT ONSHORE WINDS CONTINUE TO SUPPORT STRONG RIP
CURRENTS AND THE POSSIBILITY OF ELEVATED TIDES. LEVELS COULD
APPROACH 3 FEET FOR LOCATIONS IN AND AROUND THE HOUSTON SHIP
CHANNEL AND ALONG THE GULF FACING BEACHES OF THE BOLIVAR PENINSULA
THIS AFTERNOON AND THIS EVENING. WAVE RUN-UP HAS THE POTENTIAL TO
BE A PROBLEM FOR LOW LYING AREAS ALONG THE BOLIVAR PENINSULA. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 84 68 76 68 / 80 60 80 70 60
HOUSTON (IAH) 74 85 70 81 70 / 30 60 70 70 40
GALVESTON (GLS) 76 82 75 80 74 / 20 50 60 60 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 AM CDT MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20
TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1244 PM CDT SAT MAY 9 2015
.UPDATE...UPDATE FOR 18Z AVIATION BELOW.
&&
.AVIATION...BKN MVFR CEILINGS ACROSS HILL COUNTRY AND I-35
CORRIDOR NEAR AUS/SAT RISING THROUGH THE EARLY AFTERNOON TO VFR.
VFR CONDITIONS HAVE DEVELOPED OUT WEST NEAR DRT. CONDITIONS SHOULD
DE-STABILIZE MID TO LATE AFTERNOON...WITH SOME HI RES MODELS
INDICATING RE-DEVELOPMENT OF ISOLATED SHRA/TSTMS ALONG AND JUST
WEST OF I-35...BETWEEN 20Z-23Z. CONDITIONS WILL BE FAVORABLE FOR
SOME STORMS TO PRODUCE HAIL AND STRONG WIND GUSTS. HAVE CONTINUED
MENTION OF VCTS IN AUS/SAT/SSF TAFS ROUGHLY 21Z-02Z. TSTMS SHOULD
GRADUALLY WEAKEN AND DISSIPATE 02Z-04Z. MVFR CEILINGS RE-DEVELOPING
AUS/SAT/SSF AFTER 02Z AND AT DRT AFTER 08Z. S TO SE WINDS GUSTING
AROUND 25 KTS THROUGH THE AFTERNOON ACROSS EASTERN HALF OF THE
CWA...INCLUDING AUS/SAT/SSF.
&&
.PREV DISCUSSION... /ISSUED 1127 AM CDT SAT MAY 9 2015/
..ISOLATED SEVERE THUNDERSTORMS REMAIN POSSIBLE BEGINNING LATE
THIS AFTERNOON...
UPDATE...
SKIES ARE BEGINNING TO CLEAR IN THE FAR WESTERN ZONES AT 16Z. WILL
BE KEEPING AN EYE ON THE HILL COUNTRY AND NORTHERN I35 CORRIDOR
THIS AFTERNOON FOR BEST POTENTIAL FOR SEVERE WEATHER. HRRR MODEL
IS THE EARLIEST TO PRODUCE AFTERNOON CONVECTION...AROUND 4-5PM
ALONG A LINE FROM BURNET TO SAN ANTONIO. AS SUCH...MADE SOME
ADJUSTMENTS TO THE AFTERNOON GRIDS TO REFLECT THE LATEST
THINKING...MOST NOTABLY TO REMOVE SLIGHT CHANCE POPS OUT WEST
BASED ON THE DRYLINE`S FORECAST POSITION BY MID AFTERNOON. ALSO
POPULATED THE HOURLY DEW/WIND GRIDS FOR THE AFTERNOON PERIOD WITH
HRRR AS IT APPEARS TO BE INITIATING WELL WITH THOSE PARAMETERS.
STILL THINKING LARGE HAIL IS THE MAIN THREAT THIS AFTERNOON GIVEN
A WEAKLY CAPPED...VERY UNSTABLE...MODERATELY SHEARED ENVIRONMENT.
DAMAGING STRAIGHT LINE WINDS WILL ALSO BE A THREAT GIVEN LATEST
DEPICTIONS OF AN INVERTED V SOUNDING ON THE RAP. MODELS FORECAST
THE CAP INTEGRITY TO ERODE BY 21-22Z SO FROM THAT POINT
FORWARD...WILL BE KEEPING AN EYE ON AN AREA EAST OF A LINE FROM
JUNCTION TO UVALDE AND NORTH OF THE I10 CORRIDOR FOR ISOLATED
SEVERE THUNDERSTORM DEVELOPMENT.
WILL HAVE A MORE COMPLETE PICTURE DURING THE AFTERNOON PACKAGE
AFTER CONSIDERING THE 12Z MODEL SUITE AND LATEST HI RES MODEL
RUNS AND SURFACE ANALYSIS.
TB3
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 73 83 68 83 66 / 30 50 60 60 70
AUSTIN BERGSTROM INTL AIRPORT 73 83 68 82 66 / 30 40 60 60 70
NEW BRAUNFELS MUNI AIRPORT 73 85 69 82 67 / 30 40 50 50 70
BURNET MUNI AIRPORT 72 80 66 79 63 / 40 60 70 50 60
DEL RIO INTL AIRPORT 72 87 68 84 67 / 30 20 30 50 60
GEORGETOWN MUNI AIRPORT 73 82 66 80 64 / 40 50 70 50 70
HONDO MUNI AIRPORT 73 85 69 83 67 / 20 50 50 50 70
SAN MARCOS MUNI AIRPORT 73 84 68 82 67 / 30 40 60 50 70
LA GRANGE - FAYETTE REGIONAL 74 85 71 83 69 / 30 30 40 50 70
SAN ANTONIO INTL AIRPORT 73 85 70 83 67 / 20 40 60 50 70
STINSON MUNI AIRPORT 74 86 72 84 68 / 20 40 50 50 70
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1127 AM CDT SAT MAY 9 2015
...ISOLATED SEVERE THUNDERSTORMS REMAIN POSSIBLE BEGINNING LATE
THIS AFTERNOON...
.UPDATE...
SKIES ARE BEGINNING TO CLEAR IN THE FAR WESTERN ZONES AT 16Z. WILL
BE KEEPING AN EYE ON THE HILL COUNTRY AND NORTHERN I35 CORRIDOR
THIS AFTERNOON FOR BEST POTENTIAL FOR SEVERE WEATHER. HRRR MODEL
IS THE EARLIEST TO PRODUCE AFTERNOON CONVECTION...AROUND 4-5PM
ALONG A LINE FROM BURNET TO SAN ANTONIO. AS SUCH...MADE SOME
ADJUSTMENTS TO THE AFTERNOON GRIDS TO REFLECT THE LATEST
THINKING...MOST NOTABLY TO REMOVE SLIGHT CHANCE POPS OUT WEST
BASED ON THE DRYLINE`S FORECAST POSITION BY MID AFTERNOON. ALSO
POPULATED THE HOURLY DEW/WIND GRIDS FOR THE AFTERNOON PERIOD WITH
HRRR AS IT APPEARS TO BE INITIATING WELL WITH THOSE PARAMETERS.
STILL THINKING LARGE HAIL IS THE MAIN THREAT THIS AFTERNOON GIVEN
A WEAKLY CAPPED...VERY UNSTABLE...MODERATELY SHEARED ENVIRONMENT.
DAMAGING STRAIGHT LINE WINDS WILL ALSO BE A THREAT GIVEN LATEST
DEPICTIONS OF AN INVERTED V SOUNDING ON THE RAP. MODELS FORECAST
THE CAP INTEGRITY TO ERODE BY 21-22Z SO FROM THAT POINT
FORWARD...WILL BE KEEPING AN EYE ON AN AREA EAST OF A LINE FROM
JUNCTION TO UVALDE AND NORTH OF THE I10 CORRIDOR FOR ISOLATED
SEVERE THUNDERSTORM DEVELOPMENT.
WILL HAVE A MORE COMPLETE PICTURE DURING THE AFTERNOON PACKAGE
AFTER CONSIDERING THE 12Z MODEL SUITE AND LATEST HI RES MODEL
RUNS AND SURFACE ANALYSIS.
TB3
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 85 73 83 68 83 / 40 40 50 60 60
AUSTIN BERGSTROM INTL AIRPORT 85 73 84 69 82 / 40 30 40 60 60
NEW BRAUNFELS MUNI AIRPORT 86 73 84 69 82 / 40 30 40 50 50
BURNET MUNI AIRPORT 82 70 80 65 79 / 50 40 60 70 50
DEL RIO INTL AIRPORT 92 72 86 67 84 / 20 30 50 30 50
GEORGETOWN MUNI AIRPORT 83 72 82 67 80 / 50 30 50 70 50
HONDO MUNI AIRPORT 88 73 85 69 84 / 30 20 50 50 50
SAN MARCOS MUNI AIRPORT 86 73 84 68 82 / 30 30 40 60 50
LA GRANGE - FAYETTE REGIONAL 86 75 85 71 83 / 30 20 30 40 50
SAN ANTONIO INTL AIRPORT 87 73 85 70 83 / 40 30 40 60 50
STINSON MUNI AIRPORT 88 74 86 72 84 / 30 30 40 50 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1129 PM MDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 643 PM MDT SUN MAY 10 2015
TRAILING SHORTWAVE AND VORTICITY MAXIMA AXIS MOVING OVER EASTERN
UT EARLY THIS EVENING WILL MOVE ACROSS THE AREA OVERNIGHT. WITH
THE LIFT AHEAD OF THE SHORTWAVE NOT CLEARING THE DIVIDE UNTIL
AFTER 09Z...AND CONSIDERING CURRENT RADAR/SATELLITE TRENDS
SHOWING WHICH SHORT RANGE MODELS SEEM TO HANDLE PRETTY WELL...HAVE
UPDATED THE FORECAST TO BOOST CHANCE OF PRECIPITATION THROUGH 06Z
FOR MUCH OF EASTERN UT AND WESTERN CO...AND THEN HELD ON TO HIGHER
CHANCES OVER THE CENTRAL MOUNTAINS PAST MIDNIGHT. ISOLATED THUNDER
CAN BE EXPECTED THROUGH MID EVENING AND GUSTY NW WINDS WILL BE
COMMON NEAR ANY OF THE SHOWERS. LIGHT ACCUMULATIONS OF SNOW LIKELY
AT THE HIGHER ELEVATIONS...SOME OF WHICH WILL AFFECT PASSES.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 323 PM MDT SUN MAY 10 2015
NORTH TO NORTHWESTERLY FLOW CONTINUES ON THE BACK SIDE OF THE LOW
PRESSURE SYSTEM THAT BROUGHT ALL THE SNOW AND RAIN YESTERDAY. THE
NAM12/EC/GFS ALL SHOW A SHORTWAVE MOVING OVER THE FORECAST AREA
THIS EVENING BRINGING ANOTHER ROUND OF PRECIP WITH MOUNTAINOUS
TERRAIN SEEING MORE SNOWFALL. HOWEVER...THESE MODELS DID NOT
INITIALIZE WELL THIS MORNING AND ARE CURRENTLY OVERDOING
QPF/PRECIP. MEANWHILE...THE HRRR AND RAP13 APPEARED TO BE DOING
MUCH BETTER WITH NAILING PRECIP AND WILL FOLLOW THESE SOLUTIONS
IN THE SHORT TERM.
FOR THIS AFTERNOON THEN...WITH COLD AIR ADVECTING IN...MINOR
INSTABILITY EXISTS AND WITH CLOUDS BREAKING UP SOME...A FEW
RUMBLES POSSIBLE THIS AFTN MAINLY FOR ERN UT AND SWRN CO. FOR THIS
EVENING AND TONIGHT...THE RAP13 SHOWS ALMOST NO PRECIP WHILE THE
HRRR DOES SHOW THE WAVE MOVING THROUGH BUT PRECIP AMTS ARE LIGHT
AS THE DISTURBANCE QUICKLY MOVES OVERHEAD. PUT ISOLD/SCTD PRECIP
FOR NORTHERN VALLEYS AND ALL HIGHER TERRAIN TONIGHT.
NORTHERLY FLOW WILL ALSO BRING COOLER TEMPERATURES TO THE REGION
WITH NORTHERN VALLEYS AND SOUTHERN VALLEYS SEEING FREEZING OR JUST
BELOW FREEZING TEMPS. THESE TEMPS WILL BOTTOM OUT JUST BEFORE
SUNRISE SO OPTED TO NOT ISSUE ANY FREEZE WARNINGS. HIGH PRESSURE
WILL THEN BUILD IN BRINGING A PLEASANT START TO THE WORK WEEK.
ANOTHER LOW DRIFTING SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST
WILL CAUSE A RIDGE TO BUILD OVER THE REGION. DECENT WARM AIR
ADVECTION (WAA) COMBINED WITH A DRY SOUTHWEST FLOW WILL BRING MORE
QUIESCENT WEATHER TO FORECAST AREA MONDAY. HOWEVER...12Z GFS DID
SUGGEST THERE MAY BE ENOUGH RESIDUAL MOISTURE OVER THE EASTERN
UINTA MOUNTAINS TO FUEL A FEW DIURNAL SHOWERS/THUNDERSTORMS.
DESPITE WARMING...AFTERNOON HIGHS WILL REMAIN SEVERAL DEGREES
BELOW NORMAL.
DRY CONDITIONS PERSIST MONDAY NIGHT THOUGH THE RIDGE AXIS WILL
SHIFT EAST OF THE CONTINENTAL DIVIDE BY 12Z/TUE AS THE NORTHWEST
PACIFIC LOW PRESSURE SYSTEM MOVES ASHORE OVER SOUTHWEST OREGON.
OVERNIGHT LOWS WILL FALL TO NEAR NORMAL LEVELS AS LOSS OF CLOUD
COVER IS BALANCED BY WAA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 323 PM MDT SUN MAY 10 2015
THE LOW REMAINS NEARLY STATIONARY DURING THE DAY ON TUESDAY AS A
STRONG VORTICITY LOBE MOVES THROUGH ITS BASE. MEANWHILE...
ISENTROPIC FIELDS INDICATED A SURGE OF LOW LEVEL MOISTURE
ORIGINATING FROM THE GULF OF MEXICO WILL MOVE NORTHWARD OVER THE
CONTINENTAL DIVIDE FUELING SCATTERED SHOWERS AND THUNDERSTORMS
DURING THE AFTERNOON. OVER NORTHEAST UTAH...MODELS DIVIDED ON
WHETHER ENOUGH MOISTURE WILL REMAIN OVER THE EASTERN UINTAS TO
GENERATE MOIST CONVECTION DURING THE AFTERNOON. GIVEN MODEL
DIFFERENCES WILL CONTINUE WITH LOW CHANCES OVER THE EASTERN UINTA
MOUNTAINS. AS WAA ADVECTION CONTINUES...AFTERNOON HIGHS ARE
EXPECTED TO CONTINUE TO INCREASE WITH LATEST GUIDANCE INDICATING
HIGHS AROUND 5 DEGREES ABOVE NORMAL.
SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO TUESDAY EVENING AND
MAY PERSIST OVER THE SAN JUAN MOUNTAINS LATE INTO THE NIGHT AS A
SHORTWAVE IN THE SOUTHERN STREAM MOVES ACROSS THE SOUTHWEST.
EXPECT ANOTHER ROUND OF DIURNALLY DRIVEN MOIST CONVECTION
WEDNESDAY AFTERNOON/EVENING WITH SOME ENHANCEMENT ACROSS THE SOUTH
ASSOCIATED WITH THE SHORTWAVE TROUGH MENTIONED PREVIOUSLY. ON
THURSDAY...THE TROUGH ALONG THE PACIFIC NORTHWEST SLIPS SOUTHWARD
ALLOWING MOISTURE TO CONTINUE STREAMING NORTHWARD OVER THE DIVIDE.
AS A RESULT...EXPECT SIMILAR CONDITIONS TO WEDNESDAY WITH STORMS
LARGELY ANCHORED TO THE COLORADO MOUNTAINS. AFTERNOON HIGHS WILL
CONTINUE TO RUN SEVERAL DEGREES ABOVE NORMAL AS WAA IN SOUTHWEST
FLOW PERSISTS.
HOWEVER...THE WARM PERIOD ENDS FRIDAY AS A SLUG OF PACIFIC
MOISTURE DRIVEN ACROSS THE SOUTHWEST BY A VORTICITY LOBE EJECTED
FROM THE LOW CENTERED OVER SAN FRANCISCO COMBINES WITH GULF
MOISTURE ALREADY IN PLACE. DIABATIC COOLING ASSOCIATED WITH
INCREASED CLOUDS AND SHOWERS WILL DRIVE COOLING WITH HIGHS
DROPPING OFF BY ABOUT 10 DEGREES RELATIVE TO THURSDAY/S FORECAST
HIGHS WITH READINGS COMING IN ABOUT 5 DEGREES BELOW NORMAL. MODELS
IN FAIRLY GOOD AGREEMENT FOR THE WEEKEND WITH BOTH THE GFS AND
ECMWF DEPICTING ANOTHER MOIST...COOL...AND UNSETTLED PERIOD AS THE
LOW MOVES FROM THE WEST COAST AND ACROSS THE FORECAST AREA
EVENTUALLY REACHING THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1128 PM MDT SUN MAY 10 2015
BACK EDGE OF UPPER LEVEL SHORTWAVE CROSSING WESTERN COLORADO WILL
PASS EAST OF THE DIVIDE BY 10Z...ENDING SHOWER THREAT FOR
KEGE...KASE AND KTEX. KASE COULD SEE IFR-MVFR CONDITIONS THROUGH
ABOUT 08Z IN LIGHT SNOW. CIGS LIFT AND CLEAR OUT BY DAYBREAK WITH
VFR CONDITIONS THE RULE AT ALL SITES THROUGH THE BALANCE OF THE
TAF PERIOD.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...BEN
SHORT TERM...TGR/NL
LONG TERM...NL
AVIATION...BEN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
505 AM EDT MON MAY 11 2015
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND AMPLIFIED UPPER
LEVEL PATTERN IN PLACE ACROSS THE CONUS EARLY THIS MORNING...WITH
DEEP TROUGHING ACROSS THE CENTRAL PLAINS/MS VALLEY...AND
DOWNSTREAM RIDGING IN PLACE FORM THE GULF OF MEXICO THROUGH MUCH
OF THE EASTERN CONUS. EMBEDDED WITHIN THIS BROAD SYNOPTIC RIDGE
OVER THE EAST IS THE REMNANTS OF ANA STILL SPINNING OVER EASTERN
NORTH CAROLINA. WHAT IS LEFT OF ANA WILL BE LIFTING TO THE
NORTHEAST AND PASSING SOUTH OF THE NEW ENGLAND COAST OVER THE NEXT
24-36 HOURS. WELL TO OUR WEST ASSOCIATED WITH THE UPPER TROUGH
DIGGING THROUGH THE PLAINS STATES...WE SEE A SIGNIFICANT CLUSTER
OF THUNDERSTORMS STRETCHING FROM EASTERN TEXAS TO
ARKANSAS/MISSOURI...AND IL. FORTUNATELY FOR OUR REGION...WE ARE
PROTECTED BY WEAK RIDING ALOFT...AND THIS WILL HELP FORCE THE
ENERGY WITHIN THE TROUGH RESPONSIBLE FOR THE INCLEMENT WEATHER
TO SHEAR OUT AND PASS WELL TO OUR NORTHWEST / NORTH TODAY AND
TONIGHT.
AT THE SURFACE...ATLANTIC HIGH PRESSURE IS RIDGING BACK TO THE
WEST WITH A RIDGE AXIS ALIGNED ACROSS THE CENTRAL AND NORTHERN FL
PENINSULA/NE GULF OF MEXICO. CONDITIONS ARE DRY AND QUIET OUT
THERE ACROSS THE REGION EARLY THIS MORNING WITH NOTHING ON THE
RADAR AND EVEN VERY FEW CLOUDS IN THE SKY. TEMPERATURES ARE
RUNNING IN THE MIDDLE 60S TO LOWER 70S AT MOST SITES. WARMER
SPOTS IN THE MID/UPPER 70S CAN BE FOUND IN PINELLAS COUNTY AND
ALSO THE ISLANDS OF CHARLOTTE HARBOR.
&&
.SHORT TERM...
THE EARLY PORTION OF THE WORK WEEK WILL FEATURE A SUMMER-LIKE
PATTERN...WITH VERY WARM TEMPERATURES...AND SCATTERED LATE DAY
STORMS.
TODAY AND TONIGHT...
WEAK UPPER RIDGING WILL REMAIN IN PLACE...WHILE THE SUBTROPICAL
SURFACE RIDGE AXIS BECOMES MORE DEFINED ACROSS THE NORTHERN HALF
OF THE FL PENINSULA. THIS RIDGE POSITION WILL FAVOR SYNOPTIC FLOW
/ SEA-BREEZE CONVERGENCE ALONG AND TO THE SOUTH OF THE I-4
CORRIDOR...WHILE A MORE LIGHT/VARIABLE SYNOPTIC FLOW EXISTS
FURTHER NORTH ALONG THE NATURE COAST. WE STILL SEE SOMEWHAT DRY
CONDITIONS ALOFT...BUT NOT OVERWHELMINGLY DRY ENOUGH TO PREVENT
CONVECTION. IT IS STILL EARLY IN THE SEASON...WITH BORDERLINE
WATER TEMPERATURES ACROSS THE EASTERN GULF...SO IT MAY NOT BE
QUITE AS ACTIVE FROM TAMPA BAY SOUTHWARD AS WOULD BE EXPECTED A
MONTH OR TWO FROM NOW WITH THIS PATTERN. HOWEVER...FEEL SCT STORMS
WILL BE A FACTOR LATE IN THE DAY. SCT STORMS SHOULD BEGIN TO FIRE
OVER THE FAR SOUTHERN ZONES AFTER AROUND 19Z...AND AS IS TYPICAL
WITH THIS PATTERN...THEN MIGRATE/DEVELOP NORTHWARD WITH TIME. THE
SEA-BREEZE WILL NOT MOVE MUCH FURTHER INLAND THEN THE I-75
CORRIDOR FROM TAMPA BAY SOUTHWARD...AND SO THIS WOULD BE THE PRIME
FOCUS AREA FOR DEVELOPMENT. FURTHER NORTH...LESS SYNOPTIC
RESISTANCE WILL ALLOW THE SEABREEZE TO MOVE FURTHER
INLAND...MAKING STORMS NEAR THE IMMEDIATE COAST LESS LIKELY THAN
FURTHER SOUTH. HIRES CONVECTION ALLOWING GUIDANCE IS NOT OVERLY
IMPRESSIVE WITH UPDRAFT VELOCITIES THIS AFTERNOON...LIKELY DUE TO
WEAKER LAPSE RATES ALOFT. SO...REALLY NOT ANTICIPATING MUCH IN THE
WAY OF SEVERE STORM POTENTIAL. HOWEVER...SOME SMALL HAIL...GUSTY
WINDS...AND CERTAINLY FREQUENT LIGHTNING WILL BE THREATS.
SINCE MOST OF THE STORMS WILL HOLD OFF UNTIL LATE AFTERNOON OR
EVENING...MOST SPOTS WILL BE ABLE TO GET QUITE WARM / HOT TODAY.
TEMPERATURES AWAY FROM THE BEACHES SHOULD REACH THE LOWER 90S...WITH
EVEN A FEW MIDDLE 90S POSSIBLE SOUTH OF I-4.
SCATTERED STORMS LINGER WELL INTO THE EVENING...AND MAY NOT SEE
THE LAST OF THE STORMS MIGRATE OFF THE COAST UNTIL 02-04Z. THIS
LATE SCENARIO IS A THEME WITH MOST OF THE CONVECTIVE ALLOWING AND
PARAMETERIZED GUIDANCE. THEREFORE...KEPT POPS IN THE FORECAST
ALONG AND INSIDE THE I-75 CORRIDOR A LITTLE LONGER THAN USUAL. BY
MIDNIGHT...THINGS SHOULD GENERALLY BE QUITE ONCE AGAIN WITH A
SEASONABLE AND DRY SECOND HALF OF THE NIGHT / EARLY TUESDAY
MORNING.
TUESDAY...
LITTLE CHANGE IN THE SYNOPTIC SETUP WILL LEAD TO A SIMILAR
FORECAST TO TODAY. OVERALL MOISTURE PROFILES ARE SLIGHTLY MORE
FAVORABLE FOR CONVECTION TO THE SOUTH OF I-4...AND WILL RAISE POPS
5-10% ACROSS THESE AREAS. MUCH OF THE GUIDANCE IS AGGRESSIVE WITH
STORMS COVERAGE AROUND LEE/CHARLOTTE COUNTIES. CAN NOT ARGUE WITH
THIS SCENARIO GIVEN THE FAVORABLE SYNOPTIC FLOW PATTERN AND
BETTER MOISTURE PROFILES. HAVE GONE WITH A 60% LIKELY POP FOR
THESE ZONES...50% FURTHER NORTH TO I-4...AND 30-40% FOR THE TAMPA
BAY AREA AND NATURE COAST ZONES. ONCE AGAIN MUCH OF THIS
CONVECTION WILL HOLD OFF UNTIL VERY LATE AFTERNOON OR EVENING.
THE FORECAST WILL FEATURE LOWER 90S TEMPERATURES AWAY FROM THE
IMMEDIATE COAST.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
RIDGING ALOFT WILL DOMINATE THE GULF OF MEXICO AND FL THROUGH THE
PERIOD. AT THE SURFACE...ON WED HIGH PRESSURE SPRAWLED ACROSS THE
UPPER MID-WEST AND MID-MISSISSIPPI VALLEY WITH A WEAK FRONTAL
BOUNDARY ACROSS THE GULF COASTAL STATES AND UP ALONG THE EASTERN
SEABOARD. THROUGH FRI THE HIGH PRESSURE TREKS EAST...BRIDGING THE
FRONTAL BOUNDARY AS IS SETTLES INTO NORTH FL AND REINFORCING
THE RIDGE ACROSS FL. DURING THE WEEKEND THE HIGH PRESSURE CONTINUES
MOVING EAST ACROSS THE OPEN ATLANTIC WHILE RIDGING BACK WEST...WITH AN
AXIS ACROSS NORTH FL OR SOUTH GA. THE FRONTAL BOUNDARY LIFTS NORTH OF
THE STATE.
FORECAST PHILOSOPHY WILL CONTINUE TO BE BASED ON A MOIST SOUTHEAST OR
EAST LOW LEVEL FLOW...WITH MODEL PWAT VALUES RANGING BETWEEN 1.3 AND
1.9 INCHES. THIS MOISTURE ALONG WITH DAYTIME HEATING AND SEA BREEZE
CIRCULATIONS WILL SUPPORT ISOLATED TO SCATTERED SHOWERS AND STORMS
DURING THE AFTERNOON AND EARLY EVENING HOURS. THE SEA BREEZES WILL TEND
TO KEEP THE HIGHEST COVERAGE INLAND ALTHOUGH THE GRADIENT WILL BRIEFLY
TIGHTEN AT THE END OF THE WORK WEEK...WITH SLIGHTLY MORE ROBUST WINDS
KEEPING THE SE BREEZES CLOSER TO THE COAST. TEMPERATURES WILL RUN ABOVE
NORMAL FOR THE LOWS AND AROUND TO JUST ABOVE FOR THE HIGHS.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREVAIL ACROSS WEST CENTRAL AND
SOUTHWEST FLORIDA THROUGH THE TAF PERIOD...WITH THE EXCEPTION OF
VICINITY THUNDERSTORMS LATE THIS AFTERNOON INTO THE EVENING HOURS.
THUNDERSTORMS ARE NOT EXPECTED TO BE WIDESPREAD...BUT WILL BE
SCATTERED ACROSS THE REGION AFTER 19-20Z. KSRQ/KTBW/KPIE WILL BE
IN THE VICINITY OF THE SEA-BREEZE BOUNDARY THIS AFTERNOON / EARLY
EVENING MAKING WINDS MORE VARIABLE.
&&
.MARINE...
ATLANTIC HIGH PRESSURE WILL RIDGE BACK TO THE WEST ACROSS THE
CENTRAL AND NORTHERN FLORIDA PENINSULA AND NORTHEAST GULF OF
MEXICO THROUGH TUESDAY. WINDS WILL BE DOMINATED THE NEXT COUPLE
OF DAYS BY THE DEVELOPMENT OF AFTERNOON SEA BREEZES NEAR THE
COAST. ALTHOUGH NOT EXPECTED TO BE WIDESPREAD...THE POTENTIAL
EXISTS BOTH TODAY AND TUESDAY FOR A LATE AFTERNOON OR EVENING
THUNDERSTORM NEAR THE COAST. BY THURSDAY INTO FRIDAY...STRONGER
HIGH PRESSURE BUILDS DOWN THE EASTERN SEABOARD...PROVIDING A MORE
GENERAL EASTERLY FLOW ACROSS THE GULF AND HIGHER POTENTIAL FOR
ELEVATED WIND SURGES AT NIGHT.
&&
.FIRE WEATHER...
A RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE FLORIDA PENINSULA
THROUGH TUESDAY. DESPITE VERY WARM TEMPERATURES...ENOUGH LOW
LEVEL MOISTURE IS EXPECTED TO PREVENT CRITICAL LEVELS OF RELATIVE
HUMIDITY FROM BEING REACHED. THEREFORE NO RED FLAG CONDITIONS ARE
IN THE FORECAST. SCATTERED LATE AFTERNOON AND EVENING
THUNDERSTORMS CAN BE EXPECTED BOTH TODAY AND TUESDAY. THE MAJORITY
OF THESE LATE DAY STORMS SHOULD DEVELOP GENERALLY ALONG THE I-75
CORRIDOR...ALTHOUGH ALL ZONES WILL RUN THE RISK OF A BRIEF
DOWNPOUR
FOG IMPACT...NO SIGNIFICANT FOG IS EXPECTED THROUGH THE
TUESDAY. AREAS OF FOG ARE POSSIBLE EARLY WEDNESDAY MORNING...
ESPECIALLY TO THE NORTH OF THE I-4 CORRIDOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 73 90 74 / 40 40 40 30
FMY 92 71 91 72 / 50 30 60 30
GIF 93 72 92 72 / 40 30 40 20
SRQ 87 71 86 72 / 40 40 50 30
BKV 92 68 90 68 / 40 40 30 30
SPG 90 75 89 76 / 30 40 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM...09/RUDE
DECISION SUPPORT...09/RUDE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
327 AM CDT MON MAY 11 2015
.SHORT TERM...(TODAY)
ISSUED AT 327 AM CDT MON MAY 11 2015
07Z/2AM SURFACE ANALYSIS SHOWS 1004MB LOW OVER EASTERN SOUTH
DAKOTA...WITH FRONTAL BOUNDARY ARCING SOUTHEASTWARD THROUGH IOWA AND
MISSOURI INTO EASTERN OKLAHOMA. WHILE MUCH OF THE KILX CWA IS
CURRENTLY DRY...WIDESPREAD CONVECTION ASSOCIATED WITH A 40-45KT
850MB JET STREAK AHEAD OF THE FRONT IS OCCURRING UPSTREAM FROM
EASTERN TEXAS TO NEAR SAINT LOUIS. RADAR TRENDS SUGGEST THIS PRECIP
WILL CONTINUE TO LIFT NORTHWARD INTO CENTRAL ILLINOIS OVER THE NEXT
FEW HOURS...YIELDING A WET START TO THE DAY. COLDEST CLOUD TOPS AND
THUS THE STRONGEST CONVECTION ARE WELL TO THE SOUTH...SO AM NOT
ANTICIPATING ANY SEVERE WEATHER AS THE SHOWERS/STORMS ARRIVE THIS
MORNING. COLD FRONT WILL PUSH EASTWARD ACROSS THE MISSISSIPPI RIVER
BY MID TO LATE MORNING...THEN INTO INDIANA DURING THE AFTERNOON. AS
A RESULT...EXPECT RAIN CHANCES TO GRADUALLY TAPER OFF FROM WEST TO
EAST ACROSS THE AREA TODAY. WILL CARRY CATEGORICAL POPS ACROSS THE
BOARD THIS MORNING...THEN WILL REMOVE POPS WEST OF I-55 BY MIDDAY.
ONCE THE FRONT PASSES...SKIES WILL BECOME PARTLY TO MOSTLY SUNNY AND
WINDS WILL VEER TO THE W/SW. DUE TO A TIGHTENING PRESSURE
GRADIENT AND MIXING UP TO ABOUT 4500FT...WIND GUSTS WILL INCREASE
TO BETWEEN 25 AND 30 MPH THIS AFTERNOON. HIGH TEMPERATURES WILL
RANGE FROM AROUND 70 DEGREES IN THE ILLINOIS RIVER VALLEY...TO
THE UPPER 70S IN SOUTHEAST ILLINOIS.
&&
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 327 AM CDT MON MAY 11 2015
A BRIEF SHOT OF COOL/DRY AIR WILL ARRIVE IN THE WAKE OF THE COLD
FRONT TONIGHT THROUGH WEDNESDAY. HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY WILL REMAIN IN THE 60S IN MOST AREAS WHILE OVERNIGHT
LOWS DROP INTO THE 40S. THE COOLEST NIGHT OF THE ENTIRE FORECAST
PERIOD WILL BE TUESDAY NIGHT...WHEN HIGH PRESSURE ALLOWS WINDS TO GO
NEARLY CALM AND CORRESPONDING LOWS DROP INTO THE LOWER TO MIDDLE
40S.
ONCE THE HIGH SHIFTS OFF TO THE EAST...WARMER/MORE HUMID WEATHER
WILL RETURN FOR THE END OF THE WEEK AS A SOUTHWESTERLY UPPER FLOW
PATTERN RE-ESTABLISHES ITSELF. THIS MEANS NOT ONLY AN INCREASE IN
TEMPERATURES...BUT ALSO AN INCREASE IN RAIN CHANCES AS NUMEROUS WEAK
DISTURBANCES EMBEDDED WITHIN THE FLOW TRACK THROUGH THE REGION. 00Z
MAY 11 MODELS HAVE ALL SPED UP THE FIRST WAVE...WHICH IS NOW
EXPECTED TO TRACK FROM THE CENTRAL PLAINS THURSDAY MORNING TO THE
EASTERN GREAT LAKES BY FRIDAY EVENING. THIS IS ABOUT 12 HOURS
FASTER THAN PREVIOUS MODEL RUNS AND BRINGS RAIN INTO CENTRAL
ILLINOIS AS EARLY AS THURSDAY. DUE TO THE INITIALLY DRY AIRMASS IN
PLACE BENEATH THE SURFACE HIGH...WILL LIMIT POPS TO JUST THE WESTERN
CWA DURING THE DAY THURSDAY...WITH BETTER RAIN CHANCES ARRIVING
EVERYWHERE THURSDAY NIGHT INTO FRIDAY. AFTER THAT...LOW CHANCE POPS
WILL PERSIST THROUGH THE WEEKEND AS MOIST SOUTHWESTERLY FLOW
CONTINUES. HAVE INCREASED POPS LATE SUNDAY INTO MONDAY AS BETTER
FORCING ARRIVES AHEAD OF THE NEXT SIGNIFICANT WAVE. DUE TO THE
RISING UPPER HEIGHTS...TEMPS WILL CLIMB BACK INTO THE UPPER 70S AND
LOWER 80S OVER THE UPCOMING WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1154 PM CDT SUN MAY 10 2015
THERE IS A BREAK IN THE PCPN AT ALL TAF SITES SO WILL START ALL
SITES AS VFR WITH MID LEVEL CIGS. BASED ON THE CURRENT HRRR MODEL,
THIS WILL CONTINUE OVERNIGHT UNTIL THE NEXT ROUND OF PCPN ARRIVES
DURING THE EARLY MORNING HOURS. NOT EXPECTING ANOTHER LINE OF
STORMS WITH THE FRONT, THIS LOOKS LIKE IT WILL BE AN AREA OF RAIN
COMING UP/IN FROM SOUTHWESTERN MO. THIS AREA SHOULD REACH
SPI/DEC/CMI AROUND 10Z AND PIA/BMI AROUND 11Z. UNFORTUNATELY THIS
LIGHT RAIN WILL CONTINUE FOR A WHILE AND NOT MOVE EAST OF THE
SITES UNTIL THE SFC FRONT MOVES THROUGH. COULD BE SOME ISOLATED
THUNDER EMBEDDED IN THIS BUT BELIEVE ISOLATED ENOUGH TO NOT
WARRANT PUTTING IN THE NEW TAFS. PCPN WILL CONTINUE INTO THE LATE
MORNING FOR PIA AND SPI BUT LINGER AT BMI/DEC/CMI UNTIL AFTERNOON.
THEN EXPECTING VFR CONDITIONS ONCE THE PCPN ENDS AND SKIES WILL
BECOME CLEAR. WINDS WILL BE SOUTHERLY THROUGH THE BEGINNING BUT
BECOME WESTERLY LATER IN THE DAY AS THE FRONT MOVES THROUGH THE
AREA. WINDS WILL ALSO BECOME GUSTY LATE MORNING AND THEN WHEN THE
SKIES CLEAR CONTINUE TO BE GUSTY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT SUN MAY 10 2015
.UPDATE...
ISSUED AT 907 PM CDT SUN MAY 10 2015
MOST OF FORECAST LOOKS FINE...BUT WILL DEFINITELY BE UPDATING
POPS/WX FOR LINE OF STORMS MOVING OUT OF THE AREA. LINE OF
SCATTERED STORMS IN WESTERN MO COULD ARRIVE SOMETIME OVERNIGHT.
WILL TRY TO TIME THIS AND THEN UPDATE POPS/WX IN GRIDS AND
FORECAST. UPDATE WILL BE FORTHCOMING.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 257 PM CDT SUN MAY 10 2015
A WARM FRONT FROM JUST NORTH OF MACOMB TO JUST SOUTH OF PEORIA AND
NORTH OF BLOOMINGTON/NORMAL WILL SLOWLY LIFT NORTH ACROSS NORTHERN
COUNTIES THE REST OF TODAY...REACHING NORTH OF A GALESBURG TO LACON
LINE LATER THIS EVENING. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP NEAR THIS BOUNDARY LATE THIS AFTERNOON AND EARLY
EVENING. MEANWHILE AN AREA OF STRONG TO SEVERE THUNDERSTORMS WAS
MOVING NE INTO CENTRAL MO AND SW IA AND IS PROJECTED TO TRACK NE
ACROSS CENTRAL IL 5-11 PM. UNSTABLE AIRMASS SOUTH OF WARM FRONT WITH
CAPES OF 1000-2000 J/KG AND PROJECTED TO PEAK FROM 1500-2500 J/KG
BETWEEN 21Z-01Z. SPC HAS A SLIGHT RISK OF SEVERE STORMS LATE THIS
AFTERNOON AND THROUGH MID EVENING ACROSS CENTRAL IL EXCEPT THE 5 FAR
EASTERN COUNTIES ALONG THE INDIANA BORDER. SPC HAS 15-20% RISK OF
DAMAGING WIND GUSTS AND LARGE HAIL (1 INCH OR LARGER) AND 2% RISK OF
TORNADOES. STRONGER RISK OF SEVERE STORMS IS WEST OF IL OVER IA AND
MO WHERE STRONGER BULK SHEAR IS. MORE CONVECTION PROJECTED TO MOVE
INTO CENTRAL IL BY OVERNIGHT AHEAD OF AN APPROACHING COLD FRONT
MOVING TOWARD WEST CENTRAL IL BY 12Z MONDAY. SO HAVE INCREASING POPS
FROM WEST TO EAST DURING THIS EVENING AND KEPT HIGHER POPS
OVERNIGHT. LOWS TONIGHT MOSTLY IN THE MID 60S WITH COOLER LOWER 60S
BY GALESBURG.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 257 PM CDT SUN MAY 10 2015
MODELS HAVE COME INTO BETTER AGREEMENT WITH A SOMEWHAT FASTER COLD
FRONTAL PASSAGE ON MONDAY. THE UPSIDE TO THIS TREND IS THAT OUR
SEVERE STORM THREAT APPEARS TO BE DIMINISHING. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO BE ONGOING ACROSS MUCH OF THE FORECAST
AREA TO START THE DAY. HOWEVER THE FRONT SHOULD QUICKLY TRACK EAST
ACROSS THE WESTERN HALF OF THE FORECAST AREA DURING THE MORNING
HOURS, WITH PRECIPITATION CHANCES QUICKLY ENDING IN ITS WAKE. AT THE
CURRENTLY EXPECTED FRONTAL SPEED, ONLY LOCATIONS EAST OF THE I-57
CORRIDOR APPEAR TO HAVE TIME TO DESTABILIZE ENOUGH TO POTENTIALLY
SUPPORT SEVERE WEATHER. CAPE VALUES EAST OF I=57 ARE PROGGED TO
APPROACH 1000 J/KG AHEAD OF THE FRONT, AND 30-40 KTS OF BULK SHEAR
IS EXPECTED ALONG THE FRONT. THIS INSTABILITY/FORCING SHOULD BE
SUFFICIENT FOR A FEW SEVERE STORMS, WITH LARGE HAIL AND DAMAGING
WINDS THE PRIMARY THREATS.
COOLER/DRIER WEATHER IS EXPECTED ACROSS CENTRAL AND SOUTHEAST
ILLINOIS MONDAY NIGHT INTO MIDWEEK BEHIND THE COLD FRONT. HOWEVER,
WHILE DAYTIME HIGHS MAY ONLY BE IN THE 60S TUESDAY AND WEDNESDAY,
THE COOL AIR NOW LOOKS MORE TO BE A GLANCING BLOW AS OPPOSED TO
PREVIOUS SIGNS OF IT LASTING SEVERAL DAYS. UPPER LEVEL HEIGHTS BUILD
AND LOW LEVEL SOUTHERLY FLOW REDEVELOPS AFTER WEDNESDAY, ALLOWING
TEMPERATURES TO QUICKLY REBOUND TO ABOVE NORMAL LEVELS BY THE END OF
THE WORK WEEK. THE RETURN OF THE MORE SUMMER-LIKE CONDITIONS WILL
ALSO SIGNAL A RETURN TO UNSETTLED WEATHER BY THE END OF THE WEEK.
THE MODELS STILL EXHIBIT SPREAD IN THE DETAILS REGARDING HOW SOON
THE RAIN CHANCES RETURN, AS WELL AS WHEN CHANCES WILL BE HIGHEST.
UNFORTUNATELY, THIS FACT HAS RESULTED IN AN EXTENDED PERIOD OF
SHOWER/STORM CHANCES FROM THURSDAY NIGHT INTO THE WEEKEND ACROSS
THE ENTIRE FORECAST AREA. THE ECMWF RETURNS ITS OCCASIONAL SUPPORT
FOR PRECIPITATION AS SOON AS THURSDAY, BUT HAVE RESTRICTED THIS
THREAT TO THE WESTERN PORTION OF THE FORECAST AREA FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1154 PM CDT SUN MAY 10 2015
THERE IS A BREAK IN THE PCPN AT ALL TAF SITES SO WILL START ALL
SITES AS VFR WITH MID LEVEL CIGS. BASED ON THE CURRENT HRRR MODEL,
THIS WILL CONTINUE OVERNIGHT UNTIL THE NEXT ROUND OF PCPN ARRIVES
DURING THE EARLY MORNING HOURS. NOT EXPECTING ANOTHER LINE OF
STORMS WITH THE FRONT, THIS LOOKS LIKE IT WILL BE AN AREA OF RAIN
COMING UP/IN FROM SOUTHWESTERN MO. THIS AREA SHOULD REACH
SPI/DEC/CMI AROUND 10Z AND PIA/BMI AROUND 11Z. UNFORTUNATELY THIS
LIGHT RAIN WILL CONTINUE FOR A WHILE AND NOT MOVE EAST OF THE
SITES UNTIL THE SFC FRONT MOVES THROUGH. COULD BE SOME ISOLATED
THUNDER EMBEDDED IN THIS BUT BELIEVE ISOLATED ENOUGH TO NOT
WARRANT PUTTING IN THE NEW TAFS. PCPN WILL CONTINUE INTO THE LATE
MORNING FOR PIA AND SPI BUT LINGER AT BMI/DEC/CMI UNTIL AFTERNOON.
THEN EXPECTING VFR CONDITIONS ONCE THE PCPN ENDS AND SKIES WILL
BECOME CLEAR. WINDS WILL BE SOUTHERLY THROUGH THE BEGINNING BUT
BECOME WESTERLY LATER IN THE DAY AS THE FRONT MOVES THROUGH THE
AREA. WINDS WILL ALSO BECOME GUSTY LATE MORNING AND THEN WHEN THE
SKIES CLEAR CONTINUE TO BE GUSTY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...07
LONG TERM...BAK
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1202 AM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 847 PM CDT SUN MAY 10 2015
ANTICIPATE AT LEAST SCATTERED STORMS DEVELOPING AND/OR MOVING OVER
PORTIONS OF THE CWA REST OF TONIGHT UNTIL THE COLD FRONT PASSES
LATE. AS THE WARM FRONT CURRENTLY NEAR HWY 34 CORRIDOR LIFTS NORTH
OVERNIGHT WILL LIKELY SEE A WINDOW OF SURFACE BASED OPPORTUNITY
DEVELOP AS CWA THRUST IN WARM SECTOR AHEAD OF APPROACHING COLD
FRONT. STRENGTHENING MID/UPPER LEVEL WIND FIELDS OVERSPREADING
CWA ALONG WITH 0-6KM SHEAR OF 40+ KTS WOULD SUPPORT AT LEAST SOME
RISK OF SEVERE DESPITE THE NON-FAVORABLE TIMING AND CANNOT TOTALLY
DISCOUNT ISOLATED MARGINAL SEVERE WIND POSSIBLE IN THE STRONGEST
STORMS. ALSO...MONITORING TRENDS FOR POSSIBLY RAISING POPS OVER
THE SOUTHEAST THIRD OR SO OF CWA LATE TONIGHT INTO EARLY MONDAY AM
WITH LATEST FEW RUNS OF HRRR AND RAP MODELS SHOWING UPPER LEVEL
ENERGY AND ATTENDANT PCPN SHIELD OVER OK INTO NORTHWEST AR MOVING
NORTHEAST AND PHASING WITH COLD FRONT AS IT MOVES EAST OF THE
MISSISSIPPI RIVER.
WILL HAVE UPDATED ZFP/PFM OUT SOON.
&&
.SYNOPSIS...
ISSUED AT 240 PM CDT SUN MAY 10 2015
ANALYSIS AT 2 PM CDT SHOWS COOL AND CLOUDY EAST WINDS OVER ALL BUT
FAR SOUTH SECTIONS OF AREA. A BAND OF NON-SEVERE SHOWERS AND
THUNDERSTORMS IN MISSOURI TO PASS ACROSS THE AREA BETWEEN 10/21Z
AND 11/03Z. UPSTREAM ENERGY SUGGEST SHOWERS AND STORMS POSSIBLE
UNTIL EARLY MONDAY WITH SEVERE RISK LOW DUE TO LIMITED INSTABILITY
AND MARGINAL SHEAR AND FORCING WITH MOSTLY LIGHT TO MODERATE RAIN
AMOUNTS AS BEST FORCING TO OUR WEST AND SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 240 PM CDT SUN MAY 10 2015
SHORT TERM FORECAST CONFIDENCE ASSESSMENT...FAIR OR AVERAGE WITH COVERAGE
AND AMOUNTS OF NON-SEVERE STORMS THROUGH THIS EVENING WITH MOSTLY SHOWERS
INTO EARLY MONDAY. RAIN TOTALS MOSTLY QUARTER TO THREE QUARTERS AT MOST
WITH MANY LOCATIONS PICKING UP LESS THAN A QUARTER INCH.
TONIGHT...MOST OF PRECIPITATION TO FALL BY MIDNIGHT ALL BUT EAST AND
SOUTHEAST SECTIONS WITH AGAIN ONE QUARTER TO THREE QUARTERS OF AN INCH
THE MOST COMMON. LOWS LOWER 50S FAR WEST WITH CLEARING AND COOLER AIR
MOVING AND LOWER 60S EAST. LIGHT SOUTHERLY WINDS OF 5 TO 15 KTS EXCEPT
SOME GUSTS OVER 25 KTS POSSIBLE IN THE STRONGEST STORMS.
MONDAY...SHOWERS MAY CONTINUE INTO THE MID DAY HOURS OVER MOSTLY EAST
SECTIONS WITH CLEARING OVER MOST TO ALL THE AREA BY MID TO LATE AFTERNOON.
GUSTY WEST TO SOUTHWEST WINDS OF 10 TO 20+ KTS BEHIND THE FRONT WITH
HIGHS LOWER 60S WEST TO AROUND 70 DEGREES IN THE EAST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CDT SUN MAY 10 2015
FORECAST FOCUS ON COOL WEATHER FOR THE FIRST HALF OF THE NEW WORK
WEEK THEN WARMER WITH CHANCES FOR THUNDERSTORMS LATER IN THE WEEK
AND INTO NEXT WEEKEND.
MONDAY NIGHT THROUGH WEDNESDAY...LOW PRESSURE WILL BE TRACKING
ACROSS THE NORTHERN GREAT LAKES WITH A NORTHWEST FLOW ALOFT IN THE
WAKE OF THE SYSTEM. THIS WILL SEND BELOW NORMAL TEMPERATURES ALONG
WITH DRY WEATHER INTO THE DVN CWA. MAXIMUM TEMPERATURES ARE EXPECTED
TO BE IN THE 60S WITH LOWS MAINLY IN THE 40S. THE COOLEST NIGHT
LOOKS TO BE TUESDAY NIGHT WHEN A HIGH PRESSURE RIDGE WILL SETTLE
OVER THE AREA...BRINGING CLEAR SKIES AND LIGHT WINDS. THIS SHOULD
ALLOW FOR SOME AREAS TO DIP INTO THE MID TO UPPER 30S ESPECIALLY
ALONG HIGHWAY 20. WILL NEED TO MONITOR FOR THE POTENTIAL FOR FROST.
THURSDAY THROUGH SUNDAY...OPERATIONAL MODELS TRANSITION TO A
SOUTHWEST FLOW ALOFT ONCE AGAIN...AS A MAJOR UPPER LEVEL TROUGH
PUSHES SLOWLY EASTWARD INTO THE ROCKIES BY LATE IN THE WEEK. THIS
SYSTEM THEN LIFTS OUT INTO THE PLAINS NEXT WEEKEND. THIS WILL SET UP
THE CWA FOR PERIODS OF SHOWERS AND THUNDERSTORMS BUT TIMING OF THESE
IS DIFFICULT THIS FAR OUT IN TIME. FOR NOW WILL HAVE CHANCE POPS
EACH DAY BUT THERE WILL ALSO BE DRY PERIODS. WARMER TEMPERATURES CAN
BE EXPECTED AND BY THE TIME WE GET TO SUNDAY SOME LOCATIONS SHOULD
BE PUSHING ABOVE THE 80 DEGREE MARK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1157 PM CDT SUN MAY 10 2015
CHALLENGING TAF CYCLE IN THE SHORT TERM WITH VARIABLE CONDITIONS.
MAINLY IFR TO MVFR CONDITIONS IN FOG AND LOW CLOUDS WILL PREVAIL
AT THE NORTHERN THREE TAF SITES WITH A CHANCE OF SHOWERS AND
ISOLD STORMS UNTIL A COLD FRONT PASSES LATE TONIGHT AND EARLY
MONDAY AM. MEANWHILE... VFR AT BRL INITIALLY BUT ANTICIPATE SOME
CIGS LOWERING TO MVFR AHEAD OF COLD FRONT WITH CHANCE OF SHOWERS
AS AREA MAY BE BRUSHED BY PCPN SHIELD PASSING JUST TO SOUTHEAST.
SKIES WILL THEN DECREASE WITH VFR CONDITIONS AND WEST TO
SOUTHWEST WINDS OF 10-20 KTS AS COOLER AND DRIER AIR MOVES IN
TOWARD DAYBREAK INTO EARLY MONDAY AM. WOULD ANTICIPATE SOME
SCT-BKN STRATOCU WITH MVFR TO VFR BASES BY MID MONDAY AM THROUGH
AFTN ALONG WITH GUSTY WESTERLY WINDS AOA 10 KTS. THEN VFR
CONDITIONS MONDAY NIGHT WITH WESTERLY WINDS DECREASING BLO 10 KTS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...05
AREA FORECAST DISCUSSION
NWS PADUCAH KY
343 AM CDT MON MAY 11 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 1148 PM CDT SUN MAY 10 2015
NEW AREA OF LIGHT SHOWERS OVER SEMO MOVING NE. WILL CARRY VCSH AND
MENTION -SHRA AT KPAH AND KCGI TO COVER THIS ACTIVITY. MAY STAY JUST
WEST OF KEVV/KOWB. LIGHT SE WINDS THE RULE. MAIN PUSH OF CONVECTIVE
ACTIVITY SHOULD BE FROM LATE MORNING THROUGH MID AFTERNOON FROM WEST
TO EAST ACROSS THE AREA MONDAY. SOUTH WINDS AHEAD OF THE ACTIVITY
SHOULD BECOME WEST/SOUTHWEST AS A FRONTAL BOUNDARY MOVES THROUGH.
MAY BE SOME MVFR CIGS AND VSBYS AT TIMES AS WELL.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...RJP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
405 AM CDT MON MAY 11 2015
.SHORT TERM...
A MUCH MORE UNSETTLED WEATHER REGIME WILL TAKE HOLD OF THE AREA
TODAY...AND REMAIN IN PLACE THROUGH THE MIDDLE OF THE WEEK AS A
SERIES OF WEAK UPPER LEVEL SHORTWAVE TROUGHS RIDE ALONG THE
PERIPHERY OF A BROAD UPPER LEVEL RIDGE CENTERED OVER THE GULF OF
MEXICO. ADDITIONALLY...A WEAK SURFACE FRONT WILL STALL ALONG THE
INTERSTATE 10 CORRIDOR MONDAY NIGHT INTO TUESDAY AND SLOWLY
DISSIPATE THROUGH WEDNESDAY. THIS BOUNDARY WILL SERVE AS A FOCUS
FOR CONVECTIVE ACTIVITY BEGINNING THIS AFTERNOON AND PERSISTING
INTO WEDNESDAY.
THERE WILL BE SEVERAL ROUNDS OF HIGHER POPS ASSOCIATED WITH EACH
PASSING UPPER LEVEL VORT LOBE. THE INITIAL SURGE OF HIGHER POPS
WILL DEVELOP LATE THIS MORNING AND PERSIST INTO TOMORROW...AS A
VIGOROUS UPPER LEVEL FEATURE EJECTS OUT OF TEXAS AND SLIDES
THROUGH THE LOWER MISSISSIPPI. CONVECTION SHOULD DEVELOP OVER
CENTRAL LOUISIANA THIS MORNING AS A COLD FRONT APPROACHES FROM THE
WEST...AND ACCORDING THE LATEST HRRR MODEL RUNS...DRIVE A LINE OF
CONVECTION THROUGH THE NORTHWEST PORTION OF THE CWA DURING THE
AFTERNOON HOURS. ALTHOUGH MODEL SOUNDING PROFILES ARE NOT SHOWING
A VERY HIGH SEVERE POTENTIAL...THERE COULD BE SOME LOCALLY GUSTY
WINDS AND POSSIBLY SOME HAIL WITH THESE THUNDERSTORMS AS THEY MOVE
THROUGH THIS AFTERNOON. ANY STRONGER CONVECTION SHOULD BE FAIRLY
ISOLATED. THIS CONVECTION WILL SLOWLY DISSIPATE DURING THE
EVENING HOURS...BUT THE MESOHIGH AND COOLER AIRMASS LEFT IN THE
WAKE OF THE SYSTEM SHOULD ALLOW THE WEAK FRONTAL BOUNDARY TO
CONTINUE TO SLIDE INTO THE AREA DURING THE OVERNIGHT HOURS.
THE FRONT WILL STALL ALONG THE I-10 CORRIDOR TOMORROW AS THE
PARENT UPPER LEVEL TROUGH MOVES WELL TO THE NORTH AND EAST AND THE
DENSITY DIFFERENTIAL IN THE VICINITY OF THE FRONT WANES. AS THIS
OCCURS...THE HEART OF THE STRONG UPPER LEVEL VORT KICKING OUT OF
TEXAS WILL PASS DIRECTLY OVER THE FORECAST AREA. THERE WILL BE A
GRADIENT TO THE RAIN CHANCES WITH HIGHER CHANCES EXPECTED ALONG
AND NORTH OF THE FRONTAL BOUNDARY. FURTHER TO THE SOUTH...ONLY
ISOLATED COVERAGE IS EXPECTED THROUGH WEDNESDAY. THE REASON FOR
THIS GRADIENT IS THAT DECENT ISENTROPIC FORCING IS EXPECTED IN
THE VICINITY OF THE FRONT DURING THE DAY TOMORROW. THIS STRONGER
LOW LEVEL FORCING...COMBINED WITH THE VERY STRONG OMEGA ALOFT WILL
BRING MORE NUMEROUS SHOWERS AND THUNDERSTORMS TO AREAS NORTH OF
THE I-10 CORRIDOR.
RAIN CHANCES WILL BEGIN TO DECREASE RATHER QUICKLY TUESDAY NIGHT
AND SHOULD BE MUCH LOWER FOR WEDNESDAY AND THURSDAY AS THE INITIAL
VORT LOBE PUSHES TO THE EAST AND WEAKENS DRAMATICALLY. AT THE SAME
TIME...THE UPPER LEVEL RIDGE AXIS OVER THE GULF WILL ONCE AGAIN
BEGIN TO BUILD NORTHWARD AND SHOULD BE STRETCHED ACROSS THE
SOUTHEASTERN CONUS BOTH WEDNESDAY AND THURSDAY. THE FORECAST AREA
WILL TEND TO BE ON THE WESTERN PERIPHERY OF THIS RIDGE...AND HAVE
A NORTHWEST TO SOUTHEAST GRADIENT IN THE POPS FOR BOTH DAYS.
WEDNESDAY WILL BE THE DRIER OF THE TWO DAYS...DUE TO A LACK OF
FORCING ALOFT...AND ACTUALLY SOME WEAK SUBSIDENCE TAKING HOLD
ALOFT. THIS SUBSIDENCE MAY BE ENOUGH TO EFFECTIVELY CAP OFF MOST
OF THE CONVECTION. HOWEVER...WITH THE WEAK FRONTAL BOUNDARY STILL
LINGERING OVER THE AREA...THERE COULD BE JUST ENOUGH LOW LEVEL
CONVERGENCE TO OVERCOME THE CAP DURING PEAK HEATING HOURS AND FIRE
OFF A FEW SHOWERS AND THUNDERSTORMS. THUS...KEEP LOW END CHANCE
POPS IN PLACE FOR THE NORTHERN PARTS OF THE FORECAST AREA. ANOTHER
SHORTWAVE TROUGH WILL SLIDE INTO THE LOWER MISSISSIPPI VALLEY ON
THURSDAY...AND THIS STRONGER FORCING ALOFT WILL ALLOW FOR HIGHER
CONVECTIVE COVERAGE THROUGH THE DAY. HAVE WENT WITH CHANCE POPS
FOR MOST OF THE FORECAST AREA.
.LONG TERM...
A VERY SUMMER LIKE PATTERN WILL DEVELOP OVER THE AREA FOR THE
UPCOMING WEEKEND. THE ENTIRE REGION WILL BE BENEATH DEEP LAYER
ONSHORE FLOW ON THE WESTERN PERIPHERY OF DEEP LAYER RIDGING...WHICH
WILL KEEP A WARM AND HUMID AIRMASS OVER THE AREA. A WEAK VORT MAX
WILL SLIP THROUGH THE AREA ON FRIDAY...AND THIS DAY WILL SEE THE
HIGHEST OVERALL POPS AT 40 TO 50 PERCENT. OTHERWISE...POPS WILL
GENERALLY RANGE IN THE 30 TO 40 PERCENT RANGE FOR SATURDAY AND
SUNDAY SIMPLY DUE TO A LACK OF CAPPING ALOFT AND DAYTIME HEATING
INDUCING ENOUGH INSTABILITY TO SPARK CONVECTION. THE SHOWERS AND
THUNDERSTORMS WILL BE MOST LIKELY TO DEVELOP ALONG ANY MESOSCALE
BOUNDARIES LIKE SEABREEZES AND LINGERING OUTFLOW BOUNDARIES. THE
CONVECTION WILL TEND TO DEVELOP AS TEMPERATURES WARM IN THE LATE
MORNING AND PERSIST INTO THE EARLY EVENING HOURS. AS TEMPERATURES
COOL...THE CONVECTION WILL DISSIPATE DURING THE OVERNIGHT HOURS
WITH MAINLY DRY CONDITIONS EXPECTED OVER LAND AREAS BY MIDNIGHT.
TEMPERATURES WILL REMAIN QUITE WARM...WITH HIGHS IN THE UPPER 80S
AND LOWS IN THE UPPER 60S AND LOWER 70S EACH DAY.
&&
.AVIATION...
SOME MVFR CEILINGS IN PLACE AROUND THE AREA WITH MARINE LAYER THAT SHOULD
LIFT TO VFR LEVELS AFTER 15Z. QUASI-LINEAR CONVECTIVE SYSTEM
MOVING OUT OF ARKLATEX REGION IS PROGGED TO MOVE INTO KBTR AROUND
18Z...KMCB 19Z...KHDC 20Z...KASD 22Z...THEN WEAKENING UPON ARRIVAL
AT KMSY/KNEW/KGPT GENERALLY BETWEEN 23Z-02Z. WILL HANDLE WITH 2-3
HOUR WINDOW OF EITHER PREVAILING TSRA OR TEMPO TSRA FOR THE 4
TERMINALS PRIOR TO 22Z...THEN PROB30 FOR SOUTHEASTERNMOST
TERMINALS AFTER 23Z. A RATHER LAZY FRONTAL PASSAGE WITH CONVECTIVE
PASSAGE PRIMARILY THE FRONT BUT WITH LITTLE HIGH PRESSURE SUPPORT
UNTIL AFTER TUE 12Z. THERE MAY BE A BRIEF WINDOW OF RADIATIONAL
FOG DEVELOPMENT WITH RESIDUAL MOISTURE IN PLACE BUT APPROACH OF
UPPER DISTURBANCE AND RENEWED CONVECTIVE DEVELOPMENT MAY DISRUPT
ANY LINGERING FOG PRIOR TO 12Z. 24/RR
&&
.MARINE...
A PERSISTENT ONSHORE FLOW OF 10 TO 15 KNOTS WILL DOMINATE THE
MARINE ZONES THROUGH TUESDAY. SEAS OF 2 TO 4 FEET AND A PERIOD OF
4 TO 6 SECONDS CAN BE EXPECTED IN THE OPEN GULF WATERS DURING THIS
PERIOD. WAVES OF 1 TO 2 FEET AND A PERIOD OF AROUND 2 SECONDS IS
EXPECTED IN THE SOUNDS AND LAKES. A WEAK FRONTAL BOUNDARY WILL
BRING A WIND SHIFT TO THE NORTHEAST TUESDAY NIGHT INTO WEDNESDAY
MORNING...BUT WINDS WILL QUICKLY SHIFT BACK TO THE SOUTHEAST BY
WEDNESDAY AFTERNOON AS THIS FRONT WASHES OUT. THIS SOUTHEAST FLOW
OF AROUND 10 KNOTS WILL PERSIST INTO THE UPCOMING WEEKEND.
OVERALL...NO SIGNIFICANT WEATHER IMPACTS ARE EXPECTED IN THE
MARINE ZONES THROUGH THE ENTIRE FORECAST PERIOD.
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...ASSESSING SEVERE TSTM POTENTIAL FOR NEXT FEW DAYS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 87 69 83 65 / 40 60 60 60
BTR 88 70 85 67 / 40 60 60 60
ASD 87 69 85 66 / 20 40 50 50
MSY 87 71 85 70 / 20 40 40 40
GPT 85 72 85 69 / 10 40 40 40
PQL 86 69 85 66 / 10 30 40 40
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 AM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 414 AM EDT MON MAY 11 2015
MAIN FCST CONCERNS IN THE MEDIUM/EXTENDED RANGE WL FOCUS ON
POPS/QPF/PTYPE ON TUE AS COLDER AIR MOVES INTO THE UPR LKS IN CYC
NNW FLOW LEFT IN THE WAKE OF DEPARTING SFC LO TO THE E. AFTER A
DRYING TREND ON TUE NGT/WED ASSOCIATED WITH TRAILING HI PRES...
FOCUS FOR THE EXTENDED PERIOD WILL SHIFT TO POPS IN WAA REGIME BTWN
THIS DEPARTING HI TO THE E AND FALLING MSLP IN THE PLAINS. TEMPS
THRU WED WL RUN BLO NORMAL BUT THEN RECOVER BACK TO AVERAGE BY THE
END OF THE WEEK.
TUE...AS THE SHRTWV EXITS TO THE E...DNVA/DEEP LYR QVECTOR DVGC
UNDER RISING HGTS IN ITS WAKE AND WEAKENING LO PRES TROF/CYC FLOW WL
DIMINISH THE POPS DESPITE LINGERING DEEP MSTR. LINGERING SHOWERS WL
BE MOST PERSISTENT IN THE UPSLOPE AREAS OVER THE NRN TIER IMPACTED
BY THE N FLOW BTWN THE DEPARTING SFC LO AND APRCHG HI PRES IN MN.
THE ARRIVAL OF COLDER AIR WITH H85 TEMPS AS LO AS -5 TO -6C WL ALLOW
THE PCPN TO MIX WITH SN ON TUE ESPECIALLY OVER THE HIER TERRAIN OF
THE NCNTRL AND W. BEST CHC FOR SOME ACCUMULATING SN WL BE ON
GRASSY SFCS IN THE MRNG OVER THE W...WHERE SUFFICIENTLY COLD AIR WL
ARRIVE EARLY ENUF BEFORE DAYTIME INSOLATION CAN HAVE A BIG IMPACT
AND THERE WL BE SOME LINGERING DYNAMIC SUPPORT/SHARPER CYC FLOW
EARLY IN THE DAY. DOWNSLOPE WIND COMPONENT WL HAVE A NEGATIVE IMPACT
ON POPS OVER THE SCENTRAL. MAX TEMPS WL BE UP TO 20 DEGREES BLO
NORMAL WITH READINGS NOT RISING MUCH ABOVE 40 OVER THE HIER TERRAIN
AND NEAR LK SUP.
TUE NGT...AS THE LO EXITS TO THE E...SFC HI PRES/LLVL ACYC FLOW ARE
PROGGED TO MOVE INTO THE CWA UNDER PERSISTENT HGT RISES/DNVA/DEEP
LYR DRYING AND END LINGERING PCPN AFTER 06Z. IF SKIES CLR...MIN
TEMPS ARE LIKELY TO FALL WELL BLO 32 OVER THE INTERIOR W HALF CLOSER
TO THE INCOMING HI...WHERE WINDS WL BE LIGHTER LONGER AND PWAT WL
FALL CLOSE TO 0.25-0.30 INCH BY 12Z WED. TENDED TOWARD THE LO END OF
GUIDANCE FOR MIN TEMPS IN THIS AREA WITH EXPECTATION THIS DRYING WL
RESULT IN CLRG.
WED...AS UPR RDG BLDS INTO THE WRN GRT LKS...SFC HI PRES IS FCST TO
MOVE NEARLY OVHD. ALTHOUGH SOME MID/HI CLDS ARE FCST TO STREAM INTO
THE W DURING THE AFTN...H85 TEMPS REBOUNDING TO 1 TO 2C WL SUPPORT
MAX TEMPS NEAR 60 AWAY FM THE MODERATING INFLUENCE OF THE LKS. WITH
A LIGHT N WIND AT H925...THE MODERATION OFF LK SUP WL BE MOST SGNFT.
WED NGT THRU FRI...AS THE SFC HI PRES SHIFTS TO THE E AND A RETURN
SLY FLOW/WAA REGIME SETS UP TO THE NE OF AN H85 WARM FNT IN THE NRN
PLAINS/UPR MS RIVER VALLEY...THE MEDIUM RANGE MODELS SHOW INCRSG MID
LVL MSTR AND GENERATE AT LEAST SOME QPF NEAR/OVER UPR MI. BUT THERE
ARE TIMING/PLACEMENT DIFFERENCES AMONG THE MODELS...MAINLY DUE TO
THE VARIABILITY ON THE FCST TRACK OF SHRTWVS PROGGED TO RIDE THRU
THE UPR RDG OVER THE WRN LKS AS WELL AS THE IMPACT OF NEAR SFC DRY
AIR. GIVEN THE SPRAWLING SFC HI PRES/LLVL DRY AIR IN PLACE ON WED
NGT...TENDED TO REJECT THE MORE AGGRESSIVE 12Z ECMWF FCST OF PCPN
SPREADING INTO THE ERN ZNS SO QUICKLY. THE 00Z CNDN MODEL IS
GENERALLY THE DRIEST...WHILE THERE IS GOOD AGREEMENT AMONG THE 00Z
GFS/12Z ECMWF ON A MORE WIDESPREAD RA FOR THU NGT INTO FRI AS A MORE
WELL DEFINED SHRTWV/AREA OF UPR DVGC ENHANCED BY PLACEMENT OF CWA IN
RRQ OF UPR JET IN SE CANADA IMPACT THE AREA AND INTERACT WITH PWAT
AOA AN INCH DRIVEN INTO THE UPR LKS BY DEEP SLY FLOW AHEAD OF THE
APRCHG DISTURBANCE. A QUICK LOOK AT THE 00Z ECMWF INDICATES THIS
DISTURBANCE MAY TAKE A BIT MORE SRN TRACK...WHICH WOULD LESSEN THE
POTENTIAL FOR SGNFT PCPN OVER UPR MI.
SAT/SUN...WHILE THERE IS LIKELY TO BE A DRYING TREND IN THE WAKE OF
DISTURBANCE RESPONSIBLE FOR HIER POPS ON THU NGT/FRI...THE LONGER
RANGE MODELS INDICATE ANOTHER SHRTWV WL RIDE TOWARD THE UPR LKS THIS
COMING WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 138 AM EDT MON MAY 11 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. LOW PRES SYSTEM
MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER
LAKES...MAINLY LATE IN THE OVERNIGHT HOURS INTO THROUGH MIDDAY
TODAY. ALL SITES SHOULD STAY MVFR REST OF THE NIGHT BUT AS -SHRA
ARRIVE...EXPECT A TREND DOWN TO IFR THIS MORNING AT ALL TERMINALS.
UPSLOPE E-NE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT
KCMX/KSAW BY LATE THIS MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 AM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 417 PM EDT SUN MAY 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE WELL-DEFINED MID LEVEL
LOW THAT WAS OVER THE SRN ROCKIES YESTERDAY NOW LIFTING N ACROSS WRN
NEBRASKA/WRN SD. ONE WEAK LEAD SHORTWAVE THAT WAS OVER THE SRN
PLAINS YESTERDAY HAS MOVED NE THRU LWR MI TODAY...SPREADING SHRA AND
A FEW TSRA ACROSS LWR MI. CLOSER TO HOME...WEBCAMS INDICATED SOME
PATCHY -DZ THIS MORNING OVER ERN PARTS OF THE FCST AREA AS LOW
CLOUDS SPREAD BACK INTO MUCH OF UPPER MI. OTHERWISE...NO PCPN HAS
OCCURRED TODAY. CLOUDS HAVE DOMINATED MOST OF THE FCST AREA.
HOWEVER...MUCH OF THE WRN FCST AREA HAS BECOME MOSTLY SUNNY RECENTLY
AS THE LOW CLOUDS HAVE DISSIPATED IN THAT AREA.
TONIGHT AND MON...MID LEVEL LOW MOVING INTO SD WILL GRADUALLY OPEN
UP AS IT DRIFTS INTO MN. ON THIS TRACK...THE STRONGEST DEEP LAYER
FORCING (SHOWN NICELY BY QVECTORS) AND STRONGEST ISENTROPIC ASCENT
WILL FOCUS INTO NRN MN. FARTHER E...A WEAKER EASTWARD EXTENSION OF
DEEP LAYER FORCING COMBINED WITH A RIBBON OF REASONABLY STRONG
ISENTROPIC ASCENT LIFTING NE ACROSS THE AREA SHOULD SUPPORT A PERIOD
OF SHRA...MAINLY LATE TONIGHT THRU MON MORNING. THERE IS VERY LITTLE
TO NO INSTABILITY NOTED ACCOMPANYING THIS BAND OF FORCING/SHRA...SO
THUNDER POTENTIAL IS VERY LIMITED. WILL MAINTAIN A SCHC MENTION ONLY
OVER THE FAR SCNTRL...CLOSER TO SOMEWHAT BETTER ELEVATED INSTABILITY
TO THE S. MID LEVEL DRYING PUSHES INTO THE FCST AREA DURING THE DAY
MON...FOLLOWING THE RIBBON OF ISENTROPIC ASCENT. THIS SHOULD RESULT
IN A TRANSITION TO MAINLY DRY WEATHER OVER MOST OF THE AREA. BETTER
CHC OF LINGERING ISOLD/SCT -SHRA IN THE AFTN WILL BE OVER THE N AND
E. THAT SAID...SEEMS MORE LIKELY THAT WHERE UPSLOPE FLOW PERSISTS...
LINGERING LOW-LEVEL MOISTURE MAY RESULT IN SOME -DZ AND UPSLOPE
FOG...MAINLY ACROSS THE KEWEENAW AND NCNTRL UPPER MI. COMBINATION OF
RAIN AND HIGHER DWPTS SPREADING N OVER LAKE MI WILL LIKELY MEAN FOG
SPREADING UP LAKE MI AND AFFECTING AREAS MAINLY E OF KESC AS WELL.
LATER IN THE AFTN...BROADENING SFC LOW/OCCLUDED FRONT MAY SLIP INTO
THE SRN FCST AREA. GFS/NAM SHOW SOME LOW-LEVEL INSTABILITY (FEW
HUNDRED J/KG) NEAR THIS FEATURE. COULD SPARK ISOLD TSRA LATE...BUT
CONFIDENCE IN THAT OCCURRING IS VERY LOW. AS FOR TEMPS...THERE IS
BIG BUST POTENTIAL WITH MAX TEMPS ON MON. IF THE OCCLUDED FRONT
LIFTS INTO SRN UPPER MI AND CLOUDS BREAK...TEMPS COULD QUICKLY RISE
WELL INTO THE 60S. SOME OF THE BIAS CORRECTED GUIDANCE HAS MAX TEMPS
UP AROUND 70F NEAR THE MI/WI BORDER. FOR NOW...HAVE MAX TEMPS NEAR
60F OVER THE SCNTRL. TO THE N...WHERE FLOW REMAINS UPSLOPE OFF LAKE
SUPERIOR...TEMPS SHOULD NOT RISE HIGHER THAN THE LWR 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 PM EDT SUN MAY 10 2015
MUCH OF THIS PERIOD WILL BE COOL...WITH TEMPERATURES ONLY RETURNING
TO NEAR NORMAL FOR DAYTIME HIGHS FOR FRIDAY
FOR MONDAY NIGHT WE WILL START OFF WITH THE 500MB LOW SET UP ACROSS
MN. THE 500MB LOW WILL BECOME AN OPEN WAVE OVERNIGHT AS IT MOVES
OVER LAKE SUPERIOR AND EXITS TO THE NE TUESDAY. AT THE SFC...THE LOW
WILL BE ACROSS THE S HALF OF THE CWA AT 00Z TUESDAY...SHIFTING TO
THE E HALF BY 06Z...AND EXITING NE WITH A TROUGH LINGERING ACROSS
UPPER MI THROUGH MUCH OF THE DAY TUESDAY.
COULD WE HAVE SIGNIFICANT SNOW TUESDAY WITH THE HELP OF FAVORABLE
UPSLOPE WINDS OFF LAKE SUPERIOR BEHIND THE EXITING SFC LOW? WHILE
FCST MODELS ARE INDICATING 0-3IN OF SNOW MAINLY DURING THE DAY
TUESDAY...THERE ARE A FEW NEGATIVES TO ANY SIGNIFICANT SNOW THAT
COULD POSE A THREAT TO COMMERCE. THE NAM AND GFS DO SHOW A NOSE OF
WARMER AIR BETWEEN 750MB AND 800MB RISING ABOVE THE FREEZING LEVEL.
AT THIS POINT IT LOOKS TO BE A SMALL ENOUGH TO ONLY HAVE A SMALL
IMPACT ON SNOW. IT WILL BE NOTHING LIKE THE 20:1 SLR VALUES OF MID
WINTER. RATIOS WILL LIKELY BE ON THE ORDER OF 8:1 AND LOWER. THE MID
MAY SUN IS GIVING NEARLY 15HRS BETWEEN SUNRISE AND SUNSET. CURRENTLY
GOING WITH AN INCH OR LESS...MAINLY OVER THE FAR W HIGHER TERRAIN.
LOOK FOR RIDGING ALOFT ALREADY BY THE END OF THE DAY TUESDAY. THE
INITIAL TROUGH WILL HAVE MOVED TO E ONTARIO/S QUEBEC...WITH A
SECONDARY TROUGH EXTENDING W ACROSS S MANITOBA AND SAKATCHEWAN. AT
THE SFC...WINDS WILL ALREADY BE TURNING MORE OUT OF THE W TUESDAY
NIGHT /MAINLY OVER THE W/...IN RESPONSE TO THE LARGE NEARING AREA OF
HIGH PRESSURE EXTEDING FROM N CANADA THROUGH THE GULF STATES TUESDAY
AFTERNOON THAT WILL PUSH ACROSS THE W HALF OF THE CWA OVERNIGHT.
THE 500MB RIDGE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT LAKES
THROUGH THURSDAY AS THE CENTRAL CANADIAN TROUGH LINGERS. DRY AND
COOL AIR WILL BE OVERHEAD AS THE SFC HIGH OVER THE GREAT LAKES
THURSDAY MORNING SHIFTS E TOWARDS THE ATLANTIC.
ALTHOUGH WITH DIFFERING TIMING...THERE ARE INDICATIONS THAT A LOW IN
THE SW FLOW WILL BE ABLE TO EJECT UP ACROSS THE N PLAINS ON
THURSDAY. THE 10/12Z ECMWF SOLUTION FOLLOWS SIMILARLY TO THE
CANADIAN...WHILE THE GFS KEEPS THE SYSTEM A WHOLE LOT WEAKER AND
FARTHER TO THE S. CURRENTLY RUNNING WITH SLIGHT CHANCE TO LOW CHANCE
POPS. GIVEN THE UNCERTAINTY WITH THIS 100 PLUS HR FCST...THIS SEEMS
REASONABLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 138 AM EDT MON MAY 11 2015
CHALLENGING FCST SHAPING UP OVER THE NEXT 24HRS. LOW PRES SYSTEM
MOVING NE THRU THE PLAINS WILL SWING SHRA NE INTO THE UPPER
LAKES...MAINLY LATE IN THE OVERNIGHT HOURS INTO THROUGH MIDDAY
TODAY. ALL SITES SHOULD STAY MVFR REST OF THE NIGHT BUT AS -SHRA
ARRIVE...EXPECT A TREND DOWN TO IFR THIS MORNING AT ALL TERMINALS.
UPSLOPE E-NE FLOW WILL LIKELY RESULT IN LIFR CONDITIONS DEVELOPING AT
KCMX/KSAW BY LATE THIS MORNING. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 PM EDT SUN MAY 10 2015
TIGHT PRES GRADIENT WILL BE OVER LAKE SUPERIOR TONIGHT THRU MUCH OF
MON AS HIGH PRES REMAINS NEARLY STATIONARY...CENTERED OVER FAR NRN
ONTARIO...AND LOW PRES MOVES FROM NEBRASKA TO FAR NRN WI. AS A
RESULT BRISK NE TO E WINDS OF 15-30KT WILL BE THE RULE ACROSS LAKE
SUPERIOR. THE STRONGEST WINDS (GALE FORCE) WILL BE OVER THE WRN
PORTION OF THE LAKE WHERE COASTAL CONVERGENCE/FUNNELING AND
PERSISTENT PRES FALLS TO THE SW THRU AT LEAST EARLY MON MORNING WILL
ENHANCE THE WINDS. THE GALES OVER THE WRN PORTION OF LAKE SUPERIOR
WILL DIMINISH MON EVENING AS THE PRES GRADIENT WEAKENS AND LOW PRES
SHIFTS E OF THE AREA...RESULTING IN BACKING WINDS. WINDS WILL
DECREASE ACROSS THE LAKE FROM W TO E TUE/TUE NIGHT WITH LIGHT WINDS
MOSTLY UNDER 15KT TO FOLLOW FOR WED/THU AS HIGH PRES BUILDS INTO THE
UPPER LAKES WED AND THEN LINGERS INTO THU. AS THE HIGH PRES SHIFTS
E...WINDS MAY INCREASE A LITTLE FOR THU NIGHT/FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1117 PM CDT Sun May 10 2015
.UPDATE:
Issued at 1006 PM CDT Sun May 10 2015
While there has been a lull in shower and thunderstorms across the
area over the last few hours, the probability is expected to ramp
back up overnight. A series of disturbances currently present from
eastern TX into eastern OK are forecast to track northeastward
tonight and into the area in advance of the slowly progressive
long wave trof and attendant cold front. Backing mid/upper level
flow and large scale ascent associated with the disturbances along
with increasing low level convergence via the southwesterly LLJ is
expected to promote the northeastward spread of showers and
thunderstorms now occuring across eastern OK and northwest AR.
Recent runs of the RAP, HRRR and new 00z NAM all support this
scenario with the axis of precipitation bi-secting St. Louis at
12z. Instability has waned dramatically in the wake of the earlier
storms and loss of heating and any additional instability increase
overnight should be largely elevated and only weak. This would
suggest the severe weather threat is rather low and in the isolated
category.
Glass
&&
.SHORT TERM: (Through Late Tonight)
Issued at 431 PM CDT Sun May 10 2015
Have heavily leaned towards the afternoon runs of the HRRR for
convective trends heading into the early evening hours. N-S band of
convection is plowing east at 40-45 kts, and will likely be exiting
eastern sections of our CWA shortly after 00z. After an early
evening lull in activity convection should then return to the
CWA...with threat likely a combination of the activity now
increasing along cold front over eastern KS as well as convection
redeveloping just north of Red River.
Believe that this SE OK activity will be the dominate convection
for our area overnight, as current activity will be intensifying
the low level boundary draped across the ARKLATEX, with this dome
of rain-cooled air providing lift to increasing low level jet that
will be transporting very moist air into the region from the
southern Plains. This area will also be in a favorable area of
upper level divergence tied to RRQ of upper level jet.
Once current line of convection exits area, uncertain about
additional severe weather potential overnight. Current activity
as well as latest upstream convection will be putting a big bite
in the instability that will be available, although large scale
shear of 30-50kts still certainly suggests some severe weather
potential. In addition...while some decent rainfalls are likely
over southern sections of the CWA, believe the aforementioned
outflow boundary will keep the heaviest rain threat anchored over
AR...and south of our CWA.
Truett
.LONG TERM: (Monday through Next Sunday)
Issued at 431 PM CDT Sun May 10 2015
Convection should press east and exit the region during the day
on Monday as cold front pushes across the CWA. I`ve held onto much
higher PoPs than guidance for the early part of the morning on the
western edge of the expected precip shield (generally from near
Cuba thru STL to near Carlinville), but then quickly wind them
down to the SE of STL during the late morning and early afternoon
hours. Any severe weather potential will be strongly tied to
morning convection trends, but SWODY2 still looks reasonable that
greatest threat will be in our far southeast counties, where the
AMS will stand at least some chance of destabililzing before fropa
occurs.
As unseasonably strong upper level low spins its way across the
Great Lakes Monday night and Tuesday, it will drag much cooler air
into the area. This should result in a dry Tuesday with temps a
bit below average, as highs will primarily be in the 60s. Ridging
in the wake of the departing low will mean more tranquil weather
by midweek, with temperatures moderating into the 70s.
Another upper level system will mean a return of unsettled weather
heading into the latter half of the week. There is a large
discrepency in the medium range solutions regarding the location and
movement of this feature especially heading into next weekend, but
with all solutions suggesting a frontal boundary remaining over
the area forecast will mention a chance of thunderstorms in most
areas during the Thursday-Sunday time frame.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1104 PM CDT Sun May 10 2015
Not much change from updated TAFs sent earlier this eve. However,
confidence is low that precip will reach UIN and may just miss to
the E. Precip may miss COU just to the E as well, but confidence
is higher here. For SUS/CPS, area of SHRA with isod TS shud
continue moving newd with timing still around 09z. Timing of
precip leaving these terminals is more uncertain tho.
Otherwise, expect largely VFR conditions with wly winds increasing
with gusts to around 20-25 kts Mon aftn. These gusts shud diminish
during the eve hrs with a clear sky except at UIN with VFR bases.
Specifics for KSTL: SHRA with isod TS expected to arrive around
09z overnight and persist thru mid morning Mon. Winds will become
wly with gusts to around 25 kts and shud be slow to dissipate Mon
eve. VFR conditions largely expected outside of heavier RA.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1120 PM MDT SUN MAY 10 2015
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. AN UPPER TROF ALONG THE CANADIAN BORDER WILL AID
IN THE DEVELOPMENT OF ISOLATED SHOWERS THIS EVENING. RADAR RETURNS
SHOWING THESE SHOWERS DEVELOPING AT THIS TIME. SPC MESOSCALE
ANALYSIS INDICATES POCKETS OF CAPE OF A FEW HUNDRED J/KG WITH
HIGHER VALUES JUST ACROSS THE INTERNATIONAL BOUNDARY. LI VALUES ARE
SLIGHTLY BELOW ZERO. HRRR ANALYSIS KEEPS CONVECTIVE ACTIVITY ONGOING
THROUGH 10Z BEFORE IT DECREASES. AS A RESULT, HAVE PAINTED LOW POPS
ACROSS A BROADER AREA OVERNIGHT. ACTUAL QPF AMOUNTS STILL EXPECTED
TO BE VERY LOW. REMAINDER OF AREA WILL BE DRY. TEMPERATURES LOOK
GOOD.
&&
.AVIATION...
UPDATED 0520Z. VFR CONDITIONS EXPECTED THROUGH THE OVERNIGHT PERIOD
AND MONDAY. WEAK UPPER DISTURBANCE EXTENDING FROM KGPI TO KGGW IS
SETTING OFF SOME ISOLATED -SHRA VCNTY KCTB/KHVR BUT CEILINGS SHOULD
REMAIN AT/ABOVE 7000 FT. PRECIPITATION SHOULD TAPER OFF BY 09-10Z.
REST OF LOCAL TAF SITES WILL SEE CLEAR SKIES OR SCT HIGH CLOUDS
TONIGHT. LIGHT SURFACE WINDS ARE FORECAST ACROSS THE REGION.
WARANAUSKAS
&&
.PREV DISCUSSION...ISSUED 259 PM MDT SUN MAY 10 2015
SUNDAY THROUGH TUESDAY...COOL CONDITIONS WILL SLOWLY YIELD TO
WARMING TEMPERATURES AS SOME WEAK SHORTWAVES MOVE NEAR THE AREA
AND WILL PRODUCE LIMITED INSTABILITY ACROSS THE REGION. MOST OF
THE INSTABILITY WILL BE SEEN AS INCREASED DEVELOPMENT IN
AFTERNOON CLOUDS WITH SOME SHOWERS OVER THE HIGHER TERRAIN. SOME
ISOLATED SHOWERS WILL BE POSSIBLE ALONG THE ROCKY MOUNTAIN FRONT
AND CANADIAN BORDER SUNDAY EVENING AS A SHORTWAVE MOVES ACROSS
CANADA. ANOTHER SYSTEM WILL MOVE SOUTH OF MONTANA ON MONDAY
AFTERNOON AND COULD PRODUCE SHOWERS OFF THE HIGHER TERRAIN IN
SOUTHWEST MONTANA. OTHERWISE CONDITIONS SHOULD BE RELATIVELY QUIET
AS THE RIDGE OVER THE SOUTHERN UNITED STATE CONTINUES TO INFLUENCE
THE WEATHER PATTERN MORE AND MORE FOR MONTANA. SUK
TUESDAY NIGHT THROUGH SUNDAY...HIGH PRESSURE WILL BE SLIDING EAST
TUESDAY NIGHT AS A BROAD AREA OF LOW PRESSURE AND MOIST SOUTHWEST
FLOW MOVES ACROSS THE PACIFIC NORTHWEST. MOISTURE AHEAD OF THIS
SYSTEM WILL INCREASE THE CHANCE OF SHOWERS ACROSS THE NORTHERN AND
EASTERN PORTIONS OF THE REGION. THE LOW PRESSURE SYSTEM WILL
CONTINUE TO MOVE TOWARDS SOUTHWEST MONTANA AND THE AIRMASS WILL
BECOME A BIT UNSTABLE WEDNESDAY WITH MAINLY THE SOUTHWEST AND
CENTRAL ZONES SEEING SOME THUNDERSTORMS. THE AREA WILL REMAIN RATHER
MOIST THROUGH WEDNESDAY NIGHT BUT WEAK HIGH PRESSURE WILL RETURN
THURSDAY ALONG WITH SOME DRIER CONDITIONS, HOWEVER, THE AIRMASS WILL
REMAIN UNSETTLED AND AFTERNOON SHOWERS WILL BE POSSIBLE...AND
AFTERNOON THUNDERSTORMS ACROSS SOUTHWEST MONTANA. A LOW PRESSURE
SYSTEM WILL MOVE OVER NORTHERN CALIFORNIA FRIDAY AND MOVE INTO
NEVADA DURING THE NIGHT. THIS WILL BRING MOISTURE INTO THE SOUTHWEST
ZONES WHICH WILL THEN SPREAD NORTHEASTWARD. HEIGHTS OVER THE REGION
WILL BEGIN TO DROP AHEAD OF THIS SYSTEM AND SOME INSTABILITY AND
THUNDERSTORM DEVELOPMENT WILL COME WITH THE AFTERNOON AND EVENING
PRECIPITATION. THE LOW PRESSURE CENTER WILL MOVE TOWARDS EXTREME
SOUTHERN SOUTHWEST MONTANA BY THE WEEKEND. THE ASSOCIATED LOW
PRESSURE SYSTEM WILL BRING WRAP AROUND CIRCULATION AND MOISTURE
ACROSS THIS AREA FOR POTENTIALLY HEAVY PRECIPITATION ACROSS PORTIONS
OF SOUTHWEST MONTANA. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 33 63 37 58 / 0 10 20 20
CTB 33 56 32 56 / 10 20 10 20
HLN 35 65 40 63 / 0 10 30 30
BZN 27 62 38 63 / 0 10 20 30
WEY 22 57 30 62 / 0 10 20 40
DLN 32 64 40 64 / 0 20 20 30
HVR 32 65 34 63 / 10 20 10 20
LWT 32 62 37 60 / 10 10 20 30
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
200 AM EDT MON MAY 11 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES WILL CONTINUE FOR THE NEXT COUPLE OF
DAYS ACROSS CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TOMORROW. A
STORM SYSTEM WILL MOVE THROUGH THE AREA WEDNESDAY BRINGING THE
CHANCE FOR ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ALONG WITH
AND COOLER AIR.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
845 PM UPDATE...
FRONT CONTINUES TO HANG ACROSS NORTHERN AND WESTERN NY, WITH
SHOWERS AND EMBEDDED THUNDER SLIDING NORTHEASTWARD FROM THE
CENTRAL SO TIER TO THE WESTERN MOHAWK VALLEY. NAM12 TRIES TO BREAK
THIS ACTIVITY UP OVER THE NEXT 1-2 HOURS. HOWEVER THE HRRR KEEPS
THE ACTIVITY GOING THROUGH 8Z OR SO, AND AS OF NOW THE HRRR PROG
LOOKS TO BE HANDLING THE SITUATION BETTER.
INCREASED POPS FOR THE OVERNIGHT ALONG THE PRECIP STREAM.
245 PM EDT UPDATE... THE BACKDOOR FRONT DID MAKE IT INTO CENTRAL
NY TODAY AND IS NOW STATIONARY ALONG CENTRAL NY. BELIEVE THIS IS
AS FAR SOUTH AS IT WILL MOVE THIS AFTERNOON AS 2HR SFC PRESSURE
CHANGES ARE VERY WEAK AND SYNOPTICALLY THERE ISN`T MUCH IN THE WAY
OF FORCING TO PUSH IT FURTHER SOUTH. CONVECTION IS CURRENTLY ON-
GOING ALONG THIS BOUNDARY AND IT APPEARS THAT THEY ARE LOOSELY
DEVELOPED THUNDERSTORMS... IN THE SENSE OF 0-6 KM BULK SHEAR IS
NOT IMPRESSIVE AND THESE OUT DOWNDRAFT DOMINANT. THESE SHOWERS MAY
PRODUCE SOME GUSTY WINDS AND AT BEST SMALL NON-SEVERE SIZE HAIL
ALONG WITH BRIEF HEAVY RAINFALL. FREQUENT LIGHTNING MAY BE
POSSIBLE WITH THESE SHOWERS.
EXPECT COVERAGE OF THE SHOWERS TO INCREASE THIS AFTERNOON AS
INSTABILITY WILL INCREASE. THESE STORMS WILL MOVE TO THE NE
AROUND 20-25 MPH. THE INTENSITY OF THESE STORMS WILL WEAKEN AFTER
SUNSET AS SHOWERS ALONG THE FRONT ARE DIURNALLY DRIVEN. SOME
ISOLATED SHOWERS MAY LINGER AS WEAK INSTABILITY WILL STILL LINGER
THRU THE OVERNIGHT. THIS FRONT WILL LIFT NORTHWARD TONIGHT AND
TRANSITION INTO A PSEUDO-WARM FRONT.
TEMPS THIS AFTERNOON WILL AGAIN BE WELL ABOVE THE SEASONAL NORM.
TEMPS WILL RISE INTO THE 80S... AND MAYBE PEAK INTO THE 90S. TEMPS
ARE EXPECTED TO FALL INTO THE LOWER 60S BY SUNRISE ON MONDAY.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY/...
330 PM EDT UPDATE...
MONDAY AFTERNOON WILL BECOME UNSTABLE AGAIN AS WE REMAIN WITHIN
THE WARM SECTOR AND PLENTY OF MOISTURE WILL BE PRESENT. TEMPS
WILL REACH THE LOW 80S RESULTING IN ANOTHER UNUSUALLY WARM DAY. A
POTENT UPPR LVL TROUGH WILL MOVE INTO THE GREAT LAKES REGION
MONDAY AND PUSH A SFC LOW PRESSURE SYSTEM ACROSS THE MIDWEST.
THIS SFC LOW WILL EVENTUALLY DRAG A COLD FRONT OVER THE REGION BY
MID WEEK.
SCATTERED SHOWERS ARE EXPECTED TO DEVELOP QUICKLY LATE MONDAY MORNING
ACROSS MUCH OF THE AREA. THERE MAY BE A SLIGHT LULL IN ACTIVITY
MONDAY EVENING BEFORE ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
MOVES INTO THE CWA AHEAD OF AN APPROACHING COLD FRONT.THE COLD
FRONT IS EXPECTED TO MOVE THROUGH THE AREA TUESDAY MORNING. WINDS
WILL BE BREEZY BEHIND THE FROPA. SHOWERS AND THUNDERSTORMS MAY
LINGER THRU WED AFTERNOON. ENVIRONMENTAL CONDITIONS DO NOT LOOK
FAVORABLE TO SEVERE WITH ALONG THE COLD FRONT.
THE FRONT WILL BRING A COLDER AIRMASS OVER THE REGION. THIS WILL
RESULT IN TEMPS SLOWLY FALLING DURING THE AFTERNOON. TEMPS WILL
FALL INTO THE LOW TO MID 40S BY WED MORNING. DUE TO THE MUCH
COOLER AIRMASS TEMPS ARE ONLY EXPECTED TO RISE INTO THE 50S ACROSS
MUCH OF THE AREA WED AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
430 PM UPDATE...
FAIRLY QUIET OVERALL WITH HIGH PRESSURE BUILDING IN WEDNESDAY
NIGHT AND IN CHARGE TO FRIDAY. PATCHY FROST A POSSIBILITY IN OUR
MORE PRONE COLD SPOTS WEDNESDAY NIGHT IF WINDS DECOUPLE FAST
ENOUGH FOR A PERIOD OF GOOD RADIATIONAL COOLING. TO A LESSER
DEGREE...THURSDAY NIGHT AS WELL IF HIGH THIN CLOUDS DO NOT SPREAD
IN ON TIME AHEAD OF NEXT WAVE. THIS WAVE TRANSLATES THROUGH
ROUGHLY ZONAL FLOW...WHICH BRING A BATCH OF SHOWERS LATE FRIDAY
NIGHT INTO SATURDAY /BETTER FOCUS IS TO OUR SOUTH/. AFTER COOL
TEMPERATURES THROUGH LATE WEEK...TEMPERATURES WILL TREND BACK TO
NORMAL OR EVEN SLIGHTLY ABOVE BY LATE IN THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A TRICKY TAF FORECAST WITH A FRONTAL BOUNDARY ACROSS THE NY
TERMINALS WHICH WILL COMPLICATE THE CLOUD FORECAST AND THUS THE
POTENTIAL FOR FOG.
VFR EXPECTED AT KAVP AND KBGM AS THESE TWO SITES REMAINED DRY
SUNDAY AND THUS HAVE THE LOWEST POTENTIAL FOR FOG.
IFR VSBYS LIKELY AT KELM AND KITH. BOTH TERMINALS SAW RAIN SUNDAY
AND ARE EXPECTED TO BE CLEAR FOR AT LEAST PART OF THE NIGHT. THE
FOG MAY BE VARIABLE IN NATURE DUE TO SOME STRONGER WINDS OFF THE
DECK AND VARYING PERIODS OF CLEAR SKY. USED A TEMPO GROUP TO SHOW
THIS VARIABLE NATURE BEFORE LOCKING IN THE FOG AFTER 09Z/10Z.
AT KSYR AND KRME MOST OF THE NIGHT WILL BE CLOUDY WITH SHOWERS
AROUND. WITH THAT SAID ANY AMOUNT OF CLEAR SKY, EVEN SHORT IN
DURATION, WILL LIKELY LEAD TO FOG DUE TO OUR WET GROUND FROM
EARLIER RAINS. FEEL BEST SHOT FOR IFR VSBYS WILL BE AT KRME AS
THEY ARE ALREADY HAD PERIODS OF FOG EARLIER IN THE NIGHT.
WINDS LIGHT AND VARIABLE THROUGH DAYBREAK THEN BECOMING SOUTHWEST
AROUND 10 KTS.
.OUTLOOK...
MON NGT INTO TUE...RESTRICTIONS ARE POSSIBLE IN SHWRS/TSTMS.
WED-FRI...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KAH
NEAR TERM...DJP/KAH
SHORT TERM...KAH
LONG TERM...MDP
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1252 AM EDT MON MAY 11 2015
.SYNOPSIS...
ANA WILL GRADUALLY WEAKEN AND LIFT NORTHEAST OVER THE COASTAL
PLAIN TONIGHT INTO MONDAY. A COLD FRONT APPROACHES FROM THE
NORTHWEST TUESDAY AND MOVES OFFSHORE WEDNESDAY. HIGH PRESSURE WILL
THEN BUILD IN FROM THE NORTH THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 1 AM MON...NO BIG CHANGES TO FCST FOR THE REST OF TONIGHT
AS REMNANTS OF ANA MOVE NORTH NORTHEAST OVERNIGHT RAIN WILL
SPREAD INTO THE REMAINING COUNTIES. THEREFORE WILL LEAVE CAT TO
LIKELY POPS AS IS. REMNANTS OF ANA CURRENTLY OVER COASTAL PLAINS
SLOWLY LIFTING NORTH NORTHEAST WITH CONVECTIVE BANDS OF RAIN
SHOWERS WITH EMBEDDED THUNDER...HEAVY AT TIMES...EXPECTED FOR THE
REST OF TONIGHT. FFA CONTS FOR SW AREAS THRU 8 AM MON. ALSO...THERE
IS AN ISOLATED TOR THREAT ACRS ERN NC WITH FVRBL LOW LEVEL PROFILES
SSE SFC FLOW AND H8 WINDS VEERING SWLY. MUGGY TEMPS ARND 70
OVERNIGHT.
&&
.SHORT TERM /MONDAY/...
AS OF 345 PM SUN...SHOULD SEE THREAT FOR HEAVY RAIN SHOWERS END
THROUGH THE EARLY MORNING WITH PRECIP COVERAGE AND INTENSITY
TAPERING OFF SOMEWHAT AS REMNANTS OF THE SYSTEM WITH BEST LIFT
MOVE NORTHEAST INTO VA. STILL HUNG ONTO LIKELY POPS ACROSS THE
NORTH WITH HIGH CHANCE/SCT SOUTHERN AREAS. TEMPS WILL BE HELD DOWN
AGAIN WITH THE MOSTLY CLOUDY SKIES...THOUGH SOME SUN COULD BREAK
OUT ESP IN THE AFTERNOON WITH READINGS IN THE 80S ACROSS THE SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
REMNANT ANA LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY
NIGHT. HOWEVER A MOIST SW FLOW WILL REMAIN IN PLACE TUESDAY AHEAD
OF SHEARING UPPER TROF AND ASSOCD SFC COLD FRONT WITH CHANCES FOR
SCATTERED SHOWERS CONTINUING. MOIST BNDRY LAYER SUGGESTS MOCLDYSKIES
THRU TUESDAY MORNING THEN SUNNY BREAKS DEVELOP WITH MIXING
ALLOWING TEMPS TO SOAR TO NEAR 90 DEGREES INLAND TUESDAY
AFTERNOON. DESTABILIZATION AND SPEED SHEAR MAY BE SUPPORTIVE OF
STRONG TO SEVERE TSTORMS TUESDAY AFTERNOON INTO EVENING.
COLD FRONT SLIDES THRU THE AREA LATE TUESDAY NIGHT THEN UPPER RIDGE
BUILDS EAST WITH SFC HIGH RIDGING IN FROM THE NORTH. THE DRIER, MORE
STABLE AIRMASS WILL KEEP RAIN CHANCES AT BAY THRU AT LEAST THURSDAY
AND POSSIBLY THRU THE END OF THE WEEK UNLESS SHORT WAVE ENERGY/DEEP
MOISTURE CAN PENETRATE UPPER RIDGE MOVING OFFSHORE.
MAY BE INCREASINGLY UNSETTLED NEXT WEEKEND AS ZONAL FLOW AND STALLED
SFC BNDRY LINGER OVER THE AREA.
AFTER A HOT/HUMID TUESDAY, TEMPERATURES WILL SETTLE TO SLIGHTLY BLO
NORMAL LEVELS THRU THE END OF THE WEEK. TEMPS MAY REBOUND TO MORE
SEASONAL LEVELS NEXT WEEKEND DEPENDING ON PLACEMENT OF STALLED OUT
SFC FRONT.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 1 AM MON...IFR/MVFR CONDITIONS OVER EASTERN NORTH CAROLINA
TAFS AS REMNANTS OF ANA OVER SE NORTH CAROLINA MOVES NORTH
NORTHEAST. HRRR HAS A GOOD HANDLE ON RAIN BANDS MOVING ACROSS THE
REGION THROUGH TONIGHT. TIMING OF BANDS WILL BE DIFFICULT TO
ACCURATELY PREDICT BUT AS REMNANTS OF ANA BECOME MORE
EXTRATROPICAL BANDED PRECIPITATION WILL BECOME MORE STRATIFORM
WITH LOWER CEILINGS. AS ANA PULLS AWAY WINDS WILL SHIFT TO THE SW
THEN W IN THE MORNING AFTER 12Z.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ANA REMNANT LOW WILL BE MOVING WELL NORTH OF THE AREA MONDAY
NIGHT, HOWEVER RESIDUAL LOW LEVEL MOISTURE AND SCATTERED
PRECIPITATION MAY SUPPORT SUB-VFR CONDITIONS THRU TUESDAY MORNING.
MIXING WILL SCATTER OUT CLOUD COVER BY MIDDAY TUESDAY THEN
SCATTERED SHOWER AND THUNDERSTORMS (SOME OF WHICH CUD BE
STRONG/SEVERE) AFFECT THE AREA TUESDAY AFTERNOON AND EVENING.
DRYING AIRMASS BUILDS IN AFTER A COLD FRONT PASSAGE LATE TUESDAY
NIGHT WITH PREDOMINATE VFR EXPECTED THEREAFTER.
&&
.MARINE...
SHORT TERM /TONIGHT AND MONDAY/...
AS OF 1 AM MONDAY...LATEST LAND/BUOY OBS SHOW SOUTH TO SOUTHEAST
FLOW ACROSS THE MARINE ZONES...GENERALLY 10-20 KTS NORTH AND
15-25 KTS SOUTH WITH SEAS 3-7 FT. THE REMNANTS OF ANA WILL LIFT
NORTHEAST ACROSS THE COASTAL PLAIN OVERNIGHT WITH WINDS BECOMING
SOUTHERLY AND INCRG TO 15-25 KT ACROSS ALL WATERS AND PAMLICO
SOUND. SEAS BUILD TO 4-9 FT REST OF TONIGHT CONTG MON HIGHEST
CNTRL WATERS. SCA CONTS FOR ALL OF THE COASTAL WATERS INCLUDING
THE PAMLICO SOUND.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
DESPITE DEPARTING ANA, MARINE WEATHER REMAINS ACTIVE THRU MUCH OF
THIS WEEK. MODERATE TO STRONG SW WINDS AND LINGERING SEAS WILL
KEEP SMALL CRAFT ADVISORIES LIKELY THRU TUESDAY NIGHT AHEAD OF A
COLD FRONT PASSAGE LATE TUESDAY NIGHT OR EARLY WEDNESDAY. MAY BE A
LULL IN SMALL CRAFT ADVISORY CONDITIONS WEDNESDAY BEFORE STRONGER
POST FRONTAL N/NE WINDS KICK UP AGAIN WED NIGHT INTO THURSDAY.
WINDS/SEAS GRADUALLY RELAX THU NIGHT FRIDAY AS PRESSURE GRADIENT
DECREASES AT THE COAST WITH HIGH BUILDING IN FROM THE NORTH.
&&
.HYDROLOGY...
FLOOD WATCH ISSUED THROUGH MON MORNING AS OCCASIONAL BANDS OF
HEAVY SHOWERS PIVOT ACROSS E NC THROUGH LATE TONIGHT. THE HEAVIER
SHOWERS WILL PRODUCE RAIN RATES OF 1 INCH/HOUR OR HIGHER. HEAVIEST
RAIN THREAT LOOKS TO OCCUR OVERNIGHT TONIGHT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH UNTIL 8 AM EDT THIS MORNING FOR NCZ090>093-095-098.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT WEDNESDAY FOR AMZ135-150.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...JAC/HSA/TL
SHORT TERM...TL
LONG TERM...BTC
AVIATION...JAC/BTC/HSA
MARINE...JAC/BTC/HSA/TL
HYDROLOGY...TL/RF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
129 AM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 1237 AM CDT MON MAY 11 2015
THE MAIN FOCUS TONIGHT WILL BE SNOW ACCUMULATIONS. A SECONDARY
SURGE OF WARM/MOIST AIR AND ASSOCIATED CONVECTION IS ONGOING
ACROSS NORTH CENTRAL SOUTH DAKOTA AND SOUTH CENTRAL/SOUTHEAST
NORTH DAKOTA. THERE IS SOME CONCERN THAT ALL PRECIPITATIN WILL
REFOCUS THERE AND NECESSITATE CANCELLATION OF THE NORTHERN HALF OF
ADVISORIES. THE 12 UTC WRF ARW ALSO PUSHES THE WESTERN EDGE OF
SNOW WESTWARD BACK INTO ADAMS AND HETTINGER COUNTIES. THUS...WILL
NEED TO EXAMINE RADAR AND SATELLITE TRENDS OVER THE NEXT COUPLE
HOURS AND MAKE DECISIONS FOR THE 4 AM CDT ISSUANCE.
UPDATE ISSUED AT 932 PM CDT SUN MAY 10 2015
CONSIDERED BRIEFLY EXPANDING THE WARNING EAST A FEW COUNTIES. AFTER
CLOSE SCRUTINY OF SURFACE REPORTS WHICH ARE ALL RAIN AT THIS
TIME...CANNOT SEE ENOUGH REASON TO EXPAND THE WARNING EAST AND
NORTH. WILL LEAVE AS IS. CURRENT HRRR TRENDS DEFINITELY SHOW
INCREASING MOISTURE. BUT NAM ALSO HAS H850 TEMPS INCREASING A
DEGREE OR SO. SO DO NOT THINK THE PRECIP WILL TURN OVER TO SNOW
EARLY ENOUGH TO WARRANT EXPANSION OF THE WARNING. THINK THE
ADVISORY SHOULD COVER. CURRENT FORECAST HEADLINES LOOK GOOD. WILL
SEE RAIN CHANGE TO SNOW AFTER MIDNIGHT.
UPDATE ISSUED AT 719 PM CDT SUN MAY 10 2015
LATEST RADAR TRENDS SHOW A MOISTURE CONVEYOR FROM NORTHEAST SOUTH
DAKOTA INTO CENTRAL NORTH DAKOTA. HRRR MODEL FORECASTS A H700 LOW
TO DEEPEN AND CLOSE OFF AS IT MOVES NORTHEAST INTO SOUTHEAST
NORTH DAKOTA DURING THE NEXT 9 HOURS. THIS SHOULD SET UP
INCREASING PRECIPITATION ACROSS SOUTH CENTRAL THROUGH THE JAMES
RIVER VALLEY. WILL HAVE TO MONITOR SNOW AND RAIN AREAS CLOSELY.
NO CHANGES AT THIS TIME.
UPDATE ISSUED AT 412 PM CDT SUN MAY 10 2015
ADDED A SLIGHT CHANCE OF THUNDERSTORMS TO LAMOURE AND DICKEY
COUNTIES. SEVERAL CELLS ARE MOVING NORTH FROM NORTHEAST SOUTH
DAKOTA. THIS SHOULD LAST THROUGH 7 PM.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 305 PM CDT SUN MAY 10 2015
WINTER STORM MAIN HIGHLIGHT FOR THE SHORT TERM PERIOD.
CURRENTLY...INITIAL DEFORMATION ZONE CONTINUES BUT HAS SHOWN
SIGNS OF DISSIPATION THE LAST HOUR OR TWO ACROSS SOUTH CENTRAL
NORTH DAKOTA. DRY SLOT WORKING NORTH INTO MY SOUTHEAST WITH ONLY
ISOLATED RADAR RETURNS NOW. PRECIP TYPE HAS BEEN BOUNCING AROUND
FROM RAIN OR SNOW MANY PLACES. THE EXCEPTION WAS ACROSS PARTS OF
THE SOUTH CENTRAL WHERE 8 INCHES WAS REPORTED EARLIER IN SELFRIDGE
AND 3-5 FROM HAZELTON...WISHEK...NAPOLEON AND STRASBURG.
ALL MODELS DEPICT ANOTHER DEFORMATION ZONE AND MOISTURE SURGE
ACROSS MY SOUTHEASTERN THIRD...MAINLY EAST AND SOUTHEAST OF
BISMARCK. QUESTION IS THE EXACT PLACEMENT OF THIS FEATURE AND HOW
MUCH QPF AND/OR SNOW WILL FALL TONIGHT. CURRENTLY HAVE ANOTHER 5
INCHES FORECAST ON TOP OF THE 3-5 WHICH ALREADY OCCURRED...BUT
EVEN THIS IS QUESTIONABLE WITH THE GREAT UNCERTAINTY WITH
TEMPERATURES. OVERALL DID NOT FEEL CONFIDENT ENOUGH TO UPGRADE
KIDDER...EMMONS...LOGAN...AND MCINTOSH TO A WARNING AND WILL LEAVE
THEM IN AN ADVISORY. THE EVENING SHIFT WILL CLOSELY MONITOR SO AN
UPGRADE IS STILL POSSIBLE OVER THE NEXT SEVERAL HOURS.
NOT MUCH AT ALL OCCURRED IN THE SOUTHWEST TODAY SO REMOVED
BOWMAN...SLOPE...AND STARK FROM HEADLINES...AND TRANSITIONED ADAMS
AND HETTINGER INTO AN ADVISORY WITH ONLY 3-4 INCHES REPORTS AND
ZERO IMPACTS.
WRAP AROUND RAIN/SNOW SLOWLY MOVES EAST TONIGHT INTO MONDAY
MORNING...EXITING OFF TO OUR EAST LATE MONDAY INTO MONDAY EVENING.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN MAY 10 2015
ACTIVE FLOW ALOFT WILL PRODUCE FREQUENT CHANCES FOR WIDESPREAD
PRECIPITATION THROUGH THE EXTENDED.
CHANCES FOR RAIN AND SNOW ARE EXPECTED TO LINGER OVER EASTERN AREAS
OF THE STATE THROUGH MONDAY NIGHT...AS A BROAD UPPER LEVEL TROUGH
CONTINUES TO SLOWLY MOVE EASTWARD ACROSS THE NORTHERN PLAINS.
THE CURRENT DETERMINISTIC AND ENSEMBLE MODELS ARE PROJECTING
SOUTHWEST FLOW ALOFT BY WEDNESDAY AND CONTINUING INTO SATURDAY. AS A
RESULT...LEE TROUGHING IS EXPECTED AT THE SURFACE WITH MOISTURE
TRANSPORT AND ATMOSPHERIC INSTABILITY CREATING NUMEROUS CHANCES FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS.
CONTINUED CHANCES FOR WIDESPREAD PRECIPITATION ARE POSSIBLE...AS
ANOTHER UPPER LEVEL LOW IS PROJECTED OVER THE NORTHERN PLAINS BY
THE END OF THE PERIOD...MODELS ARE VARIED ON TIMING/LOCATION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1237 AM CDT MON MAY 11 2015
THERE IS A LARGE SPRING STORM PRODUCING WIDESPREAD IFR CONDITIONS
ACROSS SOUTH CENTRAL AND SOUTHEAST NORTH DAKOTA. KBIS-KJMS WILL
GENERALLY REMAIN IFR IN RAIN AND SNOW CHANGING TO ALL SNOW THROUGH
THE NIGHT. CONDITIONS IMPROVING TO MVFR MONDAY. KISN-KMOT WILL
REMAIN NORTH OF THE STORM WITH VFR. KDIK WILL SEE MVFR IMPROVING
TO VFR AFTER 09Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING
FOR NDZ020-041-044.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NDZ022-
023-025-035>037-046-047-050.
WINTER STORM WARNING UNTIL 7 AM CDT /6 AM MDT/ THIS MORNING FOR
NDZ034-042-045.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...AC
AVIATION...SCHECK
AREA FORECAST DISCUSSION...UPDATED
NWS MEDFORD OR
1058 PM PDT SUN MAY 10 2015
UPDATED MARINE AND AVIATION SECTIONS
.DISCUSSION...SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED LATE
THIS AFTERNOON ALONG A COLD FRONT AND AN AXIS OF INSTABILITY FROM
SOUTHERN SISKIYOU COUNTY NORTHEASTWARD TO KLAMATH AND NORTHWEST
LAKE COUNTIES. THE COLD FRONT IS CURRENTLY SHIFTING TO THE EAST OF
THE CASCADES AND WILL EXIT THE CWA OVERNIGHT INTO MONDAY MORNING.
OVERALL, EXPECT SHOWERS TO DECREASE IN COVERAGE ACROSS THE EAST
SIDE AS THE EVENING PROGRESSES, BUT STILL EXPECT ISOLATED SHOWERS
TO LINGER PAST MIDNIGHT. WEST OF THE CASCADES, THE REST OF THIS
EVENING SHOULD BE MAINLY DRY ASIDE FROM ISOLATED SHOWERS ALONG THE
IMMEDIATE COAST. AN UPPER LOW APPROACHING FROM THE PACIFIC WILL
WILL BRING MORE WIDESPREAD SHOWERS TO WEST SIDE AREAS ON MONDAY
WITH ISOLATED THUNDERSTORMS AGAIN FROM THE CASCADES TO THE EAST
SIDE. MONDAY WILL BE MUCH COOLER. MANY INLAND AREAS WILL HAVE
HIGH TEMPERATURES 15 TO 20 DEGREES LOWER THAN THEY WERE TODAY.
SPILDE
&&
.AVIATION...FOR THE 11/06Z TAF CYCLE...EAST OF THE CASCADES...MVFR
TO VFR WITH TERRAIN PARTIALLY OBSCURED AND ISOLATED TO SCATTERED
SHOWERS OVERNIGHT INTO MONDAY MORNING. FROM THE CASCADES
WESTWARD...EXPECT AREAS OF MVFR CIGS WITH TERRAIN
OBSCURED...ESPECIALLY FROM THE UMPQUA DIVIDE NORTH AND WEST. VFR
WILL PREVAIL SOUTH OF THE UMPQUA DIVIDE. AN UPPER LOW WILL MOVE INTO
THE AREA MONDAY WITH MORE NUMEROUS SHOWERS. EXPECT A MIX OF VFR/MVFR
WITH THE LOWER CONDITIONS MOST LIKELY IN HEAVIER SHOWERS. ISOLATED
THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF THE CASCADES. SPILDE
&&
.MARINE...UPDATED 1040 PM PDT SUNDAY, MAY 10, 2015...NORTH WINDS
WILL INCREASE THROUGH EARLY MONDAY RESULTING IN STEEP
SEAS FOR MOST OF THE WATERS BEYOND 10 MILES OF THE COAST AND INNER
WATERS SOUTH OF PORT ORFORD. SMALL CRAFT ADVISORY CONDITIONS ARE
EXPECTED TO LINGER THROUGH MONDAY NIGHT. SHOWERS ARE EXPECTED
MONDAY EVENING THROUGH WEDNESDAY. WINDS AND SEAS WILL DIMINISH ON
TUESDAY AND ARE LIKELY REMAIN BELOW ADVISORY LEVELS THROUGH
THURSDAY. -SCHAAF/SPILDE
&&
.PREV DISCUSSION... /ISSUED 226 PM PDT SUN MAY 10 2015/
SHORT TERM...CURRENT VISIBLE IMAGE SHOWS CUMULUS ALREADY STARTING
TO BUILD UP ALONG THE CASCADES AND FROM THE SCOTT VALLEY TO THE
TRINITY ALPS AND AND SISKIYOUS IN NORTHERN CAL AND ARE MOVING
NORTHEAST. THE PAST SEVERAL RUNS OF THE HRRR MODEL (WHICH IS
UPDATED HOURLY) CONTINUES TO SHOW SOME CONVECTIVE SHOWERS IN THE
ABOVE MENTION AREAS IN ADDITION TO SOUTH THROUGH EASTERN JACKSON
COUNTY AND NORTHERN KLAMATH COUNTY. THE MODELS SUGGEST THERE`S
ENOUGH INSTABILITY FOR ISOLATED THUNDERSTORMS LATE THIS AFTERNOON
INTO THIS EVENING. THE 700 MB WINDS ARE FROM THE SOUTHWEST, SO
SHOWERS AND ISOLATED STORMS THAT DEVELOP WILL GENERALLY MOVE
NORTHEAST. ISOLATED STORMS WILL END THIS EVENING AS WE LOSE
DAYTIME HEATING, BUT INSTABILITY SHOWERS WILL CONTINUE OVERNIGHT
AS THE UPPER TROUGH CURRENTLY NEAR 45N/130W DIGS SOUTH TOWARDS THE
OREGON COAST.
THE UPPER TROUGH WILL EVOLVE INTO AN UPPER LOW AND THIS WILL BE
RESPONSIBLE FOR BRINGING MUCH COOLER TEMPERATURES...SCATTERED
SHOWERS JUST ABOUT ANYWHERE IN THE FORECAST AREA MONDAY AND TUESDAY.
IN ADDITION, ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND EAST OF
THE CASCADES BOTH MONDAY AND TUESDAY AFTERNOON AND EARLY EVENING.
THE UPPER TROUGH WILL DIG SOUTH AND BECOME AND UPPER LOW MONDAY...
REACH THE OREGON COAST MONDAY AFTERNOON, THEN MOVE OVER THE AREA
MONDAY NIGHT INTO TUESDAY. THE MODELS HAVE COME INTO BETTER AGREEMENT
WITH THE PLACEMENT OF THE UPPER LOW WHICH YIELDS HIGHER CONFIDENCE
WE`LL BE COOL AND WET FOR THE START OF NEXT WEEK. THE MODELS ALSO
SHOW THE GREATEST INSTABILITY ALONG AND EAST OF THE CASCADES AND
PLENTY OF SHORTWAVES WILL MOVE OUT AHEAD OF THE UPPER LOW MONDAY
PROVIDING THE TRIGGER FOR ISOLATED STORMS TO FIRE UP.
THE UPPER LOW WILL MOVE OVERHEAD ON TUESDAY BRINGING COLD AIR ALOFT
WITH 500 MB TEMPERATURES BETWEEN -25 AND -28C. SHOWERS WILL OCCUR
JUST ABOUT ANYWHERE TUESDAY WITH SOME MODERATE TO HEAVY IN THE
AFTERNOON AS WE REACH MAX HEATING. SNOW LEVELS TUESDAY ARE EXPECTED
TO BE AROUND 5000 FEET, BUT WILL TEMPORARILY LOWER IN HEAVIER
SHOWERS. RIGHT NOW, WERE ONLY EXPECTING SNOW TO ACCUMULATE OVER THE
HIGHER TERRAIN ALONG AND EAST OF THE CASCADES. ISOLATED
THUNDERSTORMS REMAIN A CONCERN TUESDAY AFTERNOON ALONG AND EAST OF
THE CASCADES.
SHOWERS ARE EXPECTED TO GRADUALLY DECREASE TUESDAY NIGHT AS THE
UPPER LOW WEAKENS AND MOVES NORTH. HOWEVER THE NAM SHOW ANOTHER
SHORTWAVE ON THE HEALS OF THE UPPER TROUGH AND WE COULD SEE SHOWERS
INCREASE AGAIN EARLY WEDNESDAY MORNING. THE GFS IS SLOWER WITH THE
NEXT SHORTWAVE AND EC IS ALSO SLOWER AND WEAKER. EITHER ONE OF THESE
SOLUTIONS WILL RESULT IN A COOL AND UNSETTLED PATTERN ON WEDNESDAY.
-PETRUCELLI
LONG TERM...THURSDAY THROUGH SUNDAY...AN ACTIVE SHOWERY PATTERN
WITH A SLIGHT OF THUNDERSTORMS CONTINUES THROUGH THE EXTENDED
PERIOD AS AN UPPER LOW SHIFTS SOUTH AND THEN MOVES INLAND. ON
THURSDAY A STRONG UPPER LOW IS FORECAST TO SHIFT SOUTH OFF THE
CALIFORNIA COAST. SOUTHERLY MOISTURE IS FORECAST TO MOVE INTO THE
AREA AHEAD OF THIS LOW AND BRING SHOWERS ALONG WITH A SLIGHT
CHANCE OF THUNDERSTORMS ACROSS THE AREA. GIVEN THE SOUTH TO
SOUTHEAST FLOW ALOFT, HAVE EXTENDED THE SLIGHT RISK FOR
THUNDERSTORMS FURTHER WEST TO INCLUDE SOME WESTERN VALLEYS AS WELL
AS FROM THE CASCADES EAST. ON FRIDAY...THE UPPER LOW IS FORECAST
TO MOVE INTO SOUTHERN AND CENTRAL CALIFORNIA. MODELS CONTINUE TO
SHOW MOISTURE MOVING AROUND THE LOW INTO THE AREA ON FRIDAY WITH
INSTABILITY BRINGING A MIX OF SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS. ON FRIDAY, THE BEST CHANCE FOR ANY THUNDERSTORMS IS
EXPECTED FROM THE CASCADES EASTWARD ON FRIDAY BUT MAY EXTEND
FURTHER WEST ALONG THE WESTERN SLOPES OF THE CASCADES AND INTO
CENTRAL AND WESTERN SISKIYOU COUNTY. ON SATURDAY...AS THIS UPPER
LOW MOVES INLAND TO THE EAST- NORTHEAST...EXPECT SOME CONTINUED
SHOWER ACTIVITY OVER THE AREA. THE SLIGHT CHANCE OF THUNDERSTORMS
IS EXPECTED ONLY FOR FAR EASTERN ZONES IN LAKE AND MODOC COUNTIES.
LATE SATURDAY INTO SUNDAY...THE AREA MAY BE LOCATED BETWEEN THE
UPPER LOW WELL TO THE EAST AND A WEAK UPPER LOW OFF THE OREGON
COAST. DEPENDING ON THE POSITION OF THESE LOWS, MAY SEE SOME
CONTINUED SHOWERS OVER THE AREA. ALSO IF THE UPPER LOW OFF THE
COAST OF OREGON TRENDS STRONGER, MAY SEE ANOTHER CHANCE FOR
THUNDERSTORMS IN THE AREA ON SUNDAY. /CC
FIRE WEATHER...UPDATED 100 PM PDT SUNDAY, MAY 10, 2015...A WEAK
COLD FRONT WILL PERSIST OVER THE AREA THIS AFTERNOON AND EVENING
ALLOWING SHOWERS AND ISOLATED THUNDERSTORMS TO DEVELOP FROM ABOUT
THE SHASTA AND SCOTT VALLEYS NORTHWARD TO THE SISKIYOUS AND INTO THE
CASCADES THIS AFTERNOON. STORMS ARE ALSO POSSIBLE ALONG THE WESTERN
SLOPES OF THE CASCADES AND INTO PORTIONS OF THE ROGUE VALLEY LATE
THIS AFTERNOON. THEN THIS EVENING...EXPECT ISOLATED THUNDERSTORMS
FROM THE CASCADES EASTWARD. MID-LEVEL SOUTHWEST FLOW WITH NORTHWEST
FLOW IN THE LOWER LEVELS WILL CAUSE WINDS AND MOISTURE TO CONVERGE
IN THESE AREAS AND MODELS CONTINUE TO SHOW INSTABILITY WITH THE
POTENTIAL FOR ISOLATED THUNDERSTORMS. STORMS SHOULD GENERALLY
PRODUCE RAINFALL, THOUGH AMOUNTS ARE LIKELY TO BE LIGHT TO MODERATE
AT 0.10" TO 0.25" OR LESS. STORMS ARE EXPECTED TO MOVE FROM
SOUTHWEST TO NORTHEAST AT 10-20 KNOTS. THE STORMS WILL CAPABLE OF
GUSTY OUTFLOW WINDS OF 25 TO 35 MPH AND SMALL HAIL. GUSTY WEST TO
SOUTHWEST WINDS ARE EXPECTED AHEAD OF THE FRONT OVER THE EAST SIDE
THIS AFTERNOON, WITH GUSTY NORTHWEST WINDS BEHIND IT ON THE WEST
SIDE.
SCATTERED SHOWERS ACROSS THE AREA TONIGHT WILL INCREASE IN
COVERAGE AND INTENSITY MONDAY MORNING THROUGH MONDAY EVENING AS AN
UPPER LOW MOVES INTO THE COAST. ISOLATED THUNDERSTORMS MIXED WITH
SHOWERS ARE EXPECTED ON THE EAST SIDE MONDAY AFTERNOON AND
EVENING, PRIMARILY FOR EASTERN SISKIYOU, MODOC, EASTERN KLAMATH
AND LAKE COUNTIES. THEN SHOWERS AND ISOLATED THUNDERSTORMS ARE
LIKELY OVER MUCH OF THE AREA ON TUESDAY AS THE UPPER LEVEL LOW
MOVES OVERHEAD. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL
11 PM PDT MONDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 2 AM TO 11 PM PDT MONDAY FOR
PZZ376.
$$
MAS/MAP/CC/TRW/BMS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
248 AM EDT MON MAY 11 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHEAST
CONUS THROUGH MONDAY. A SHARP COLD FRONT WILL CROSS THE AREA
EARLY TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING
SOUTHEAST INTO PA FOR THE SECOND PART OF THE WORK WEEK. AFTER A
TASTE OF EARLY SUMMER WEATHER...TEMPERATURES WILL AVERAGE BELOW
NORMAL.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
REGIONAL RADAR LOOP SHOWING SCT CONVECTION WORKING INTO THE NW
MTNS AT 06Z IN ASSOC WITH A WEAK SHORTWAVE RIDING ALONG NW EDGE
OF UPPER RIDGE. HRRR SUPPORTS CHC POPS OF A SHRA/TSRA ACROSS THE
NW MTNS DURING THE PRE-DAWN HOURS...THEN A DIMINISHING CHC OF
PRECIP BY 12Z...AS SHORTWAVE LIFTS NORTH OF THE AREA.
ELSEWHERE...FOCUS EARLY THIS MORNING IN ON MARINE STRATUS DECK
ADVECTING INTO SOUTHEAST PA. LATEST SREF/RAP DATA SUPPORT MCLDY
SKIES BY DAWN EAST OF THE SUSQ RIVER. TEMPS ON TRACK TO BOTTOM
OUT BTWN 60-65F ACROSS THE AREA.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE REMNANTS OF TS ANA ARE STILL EXPECTED TO PASS FAR ENOUGH
SOUTH OF PA TO NOT DIRECTLY IMPACT THE AREA TODAY. AS RIDGE AXIS
SLIDES EAST...PLUME OF HIGHER PWATS WILL OVERSPREAD THE REGION
TODAY. THE INCREASED HUMIDITY/INSTABILITY SHOULD RESULT IN BETTER
COVERAGE OF TSRA THIS AFTN...ESP ACROSS THE CENTRAL MTNS. AN
EXAMINATION OF MDL SOUNDINGS SHOWS MODERATE CAPE OF ARND 1500 J/KG
AND WEAK SHEAR...IMPLYING MOSTLY PULSE TYPE CONVECTION W/LITTLE
RISK OF ORGANIZED SVR WX. MDL 8H TEMPS SUPPORT HIGHS IN THE
L/M80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
EXPECTING SOME SHOWERS AND THUNDERSTORMS FOR MONDAY NIGHT.
HIGHEST POPS TO THE WEST AND NORTH...GIVEN THE TIMING OF
THE COLD FRONT AND THE BEST DYNAMICS TRACK TO THE WEST
AND NORTH.
SOME SHOWERS POSSIBLE STILL ON TUE...MAINLY DURING THE FIRST
PART OF THE DAY...GIVEN TIMING OF THE COLD FRONT.
DAY 3 OUTLOOK HAS NO SEVERE FOR CENTRAL PA. MAKES SENSE...GIVEN
TIMING OF THE FROPA...WEAK HEIGHT FALLS...AND LACK OF SURFACE
CONVERGENCE. REMAINS OF ANA AID IN SHIFTING THE WINDS MORE TO THE
WEST BEFORE THE COLD FRONT GETS INTO THE AREA. WHILE THE UPPER
LVL TROUGH IS RATHER STRONG...IT LAGS THE COLD FRONT.
SOME SHOWERS FOR TUE NIGHT INTO WED ACROSS THE NORTH AND PERHAPS
THE LAURELS...GIVEN THE UPPER LVL LOW AND COLD AIR ALOFT.
THU AND FRI LOOKING DRY...BUT ON THE COOL SIDE. WILL HAVE TO
MONITOR FOR THE NEED FOR FROST AND FREEZE PRODUCTS.
MID SHIFT INSERTED LOW POPS FOR FRIDAY NIGHT INTO SAT. MODELS
STILL SHOW A SHORT WAVE DROPPING SE IN THE NW FLOW. MOISTURE
LIKELY TO BE LIMITED...BUT GIVEN THE DIRECTIONAL SHEAR...SOME
SUPPORT FOR SHOWERS AND PERHAPS A THUNDERSTORM. THUS LEFT THE
SHOWERS IN.
DID NOT CARRY SHOWERS PAST SUNDAY MORNING...AS MODELS SHOW
RIDGING ALOFT. WENT WITH A DRY FCST FOR MONDAY FOR NOW. BEST
WARM ADVECTION IS TO THE WEST.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
UPPER RIDGE REMAINS OVER THE REGION TONIGHT. SCT SHRA/TSRA WILL
BE CONFINED TO THE FAR WEST/NORTHWEST RTES AS A SHORTWAVE TROF
ROTATES EWD FROM NE OHIO INTO THE FINGERLAKES REGION AND STORMS
AND SHOWERS STREAM OVER THE SLOWLY WEAKENING RIDGE. ANY
CONVECTION THAT DOES GET GOING WILL DIMINISH QUICKLY WITH LOSS OF
HEATING AS THE EVENING CONTINUES. FOCUS THEN SHIFTS BACK TO
OVERNIGHT REDEVELOPMENT OF STRATUS/FOG OVER SE PORTIONS OF PA.
SREF CIG PROBS AND MDL SOUNDINGS SUGGEST THE LOW CLOUDS COULD
REACH ALL THE WAY INTO THE CENTRAL MTNS. BETTER CHC OF SHRA/TSRA
ON MON AS MOISTURE INCREASES REGION WIDE AS THE RIDGE BREAKS
DOWN AND WARMER THAN NORMAL DAYTIME HIGHS.
OUTLOOK...
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
FRI...MVFR WITH SCT SHRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/MARTIN
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO/FITZGERALD
LONG TERM...MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
340 AM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL TURN NORTHEAST AND MOVE ACROSS EASTERN
TODAY...BEFORE MOVING OFF THE VIRGINIA COAST. A COLD FRONT WILL
CROSS OUR AREA ON TUESDAY. HIGH PRESSURE WILL MOVE FROM THE GREAT
LAKES WEDNESDAY TO OFF THE MID ATLANTIC COAST BY NEXT WEEKEND AS
MOISTURE FLOWS UP FROM THE GULF AND INTO OUR AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM...ISOLATED CONVECTION CONTINUES TO FIRE ALONG A
GRADIENT IN MUCAPE SOUTH OF THE I-85 CORRIDOR THIS MORNING. WILL
CONTINUE TO RETAIN 20 POPS IN THIS AREA THROUGH ABOUT DAYBREAK.
OTHERWISE...ATTENTION TURNS TO THE CONVECTIVE POTENTIAL FOR LATER
TODAY. DEWPOINTS IN THE MID/UPPER 60S ARE EXPECTED TO COMBINE WITH
STEEP LOW LEVEL LAPSE RATES TO YIELD SOME OF THE MORE ROBUST CAPE
VALUES WE/VE SEEN IN RECENT DAYS...WITH A CONSENSUS OF DETERMINISTIC
AND ENSEMBLE GUIDANCE CLEARLY SUPPORTING SBCAPE IN THE 2000-2500
J/KG RANGE THIS AFTERNOON. IN ADDITION...MOISTURE WILL BE MORE
PLENTIFUL THROUGH A DEEP LAYER...WITH PWATS OF AROUND 1.5...OR ABOUT
2 STANDARD DEVS ABOVE CLIMO...EXPECTED ACROSS THE PIEDMONT THIS PM.
WHAT WILL BE LACKING IS AN OBVIOUS SOURCE OF ORGANIZED LIFT.
HOWEVER...IT IS INTERESTING THAT SOME OF THE CONVECTION-ALLOWING
MODELS...AND EVEN THE NAM APPEAR TO BE HIGHLIGHTING A LOW LEVEL
CONVERGENCE AXIS ACROSS EAST TENN AND NORTH GA. THE HRRR AND NSSL
WRF LIGHT THIS AREA UP...SUGGESTING (AT LEAST) NUMEROUS CONVECTIVE
COVERAGE BY EARLY/MID AFTERNOON...WHICH WOULD PUSH INTO OUR AREA
BY MID/LATE AFTERNOON. LIKELY POPS WILL BE CARRIED OVER THE
MTNS...WHERE DIFF HEATING STILL APPEARS TO BE THE BEST BET FOR
INITIATING CONVECTION. HOWEVER...POPS HAVE ALSO BEEN BUMPED TO 50
PERCENT ACROSS MUCH OF THE REMAINDER OF THE WESTERN HALF OF THE
FORECAST AREA. IF THE MESOSCALE MODELS HAVE THE RIGHT IDEA...
THIS WILL BE TOO LOW. WHILE PROFILES ARE GENERALLY MOIST...STEEP
LOW LEVEL LAPSE RATES/A HOT BOUNDARY LAYER SHOULD YIELD
DOWNDRAFT CAPE IN THE 500-1000 J/KG RANGE THIS AFTERNOON...WHICH
COULD COMBINE WITH WEAK SHEAR AND WATER LOADING TO YIELD A WET
MICROBURST THREAT WITH SOME OF THE STRONGER UPDRAFTS. WHILE DEEP
LAYER SHEAR IS WEAK...THERE COULD BE JUST ENOUGH SHEAR OVER COLD
POOL DEPTH TO PROMOTE SOME DEGREE OF LIMITED UPSCALE ORGANIZATION...
WHICH WOULD RESULT IN A MORE ORGANIZED DOWNBURST THREAT.
COVERAGE OF CONVECTION WILL GRADUALLY DIMINISH TONIGHT. A COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY
OVERNIGHT. HOWEVER...THERE IS A DEFINITIVE MODEL CONSENSUS
SUGGESTING THAT ANY ASSOCIATED CONVECTION WILL BE DIMINISHING AS THE
BOUNDARY NUDGES INTO THE FORECAST AREA TOWARD DAYBREAK. TOKEN SMALL
CHANCE POPS WILL NEVERTHELESS BE RETAINED. TEMPERATURES WILL REMAIN
A SOLID 10 DEGREES ABOVE CLIMO THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AT 300 AM EDT MONDAY...ON TUESDAY MORNING NEARLY ZONAL FLOW WILL
EXTEND FROM THE SOUTHERN ROCKIES TO THE MID ATLANTIC COAST...WHILE
AN UPPER TROUGH CROSSES THE GREAT LAKES. ON WEDNESDAY AND UPPER
RIDGE AMPLIFIES OVER THE MS RIVER VALLEY. ON WEDNESDAY NIGHT THIS
RIDGE PROGRESSES TO THE TN AND OH RIVER VALLEYS AND THE GREAT LAKES.
A COLD FRONT WILL CROSS OUR AREA EARLY TUESDAY...ACCOMPANIED BY
PRECIPITATION. INSTABILITY WILL SUPPORT THUNDERSTORMS ALONG AND
AHEAD OF THE FRONT...AND SOME SHEAR WILL BE PRESENT...PERHAPS
SUPPORTING SOME ORGANIZATION TO THE STORMS.
THE FRONT STALLS NEAR THE GULF COAST ON TUESDAY NIGHT...WHILE DRIER
AIR MOVES INTO OUR AREA FROM THE NW. DRY HIGH PRESSURE BUILDS DOWN
THE EAST SLOPES OF THE APPALACHIANS ON WEDNESDAY NIGHT...WHILE THE
STALLED FRONT REMAINS TO OUR S. TEMPERATURES WILL RUN WELL ABOVE
NORMAL IN DOWNSLOPE WARMING BEHIND THE FRONT...COOLING TO SLIGHTLY
ABOVE NORMAL AS COOLING WITH THE POST FRONTAL AIR MASS IS OFFSET BY
RISING HEIGHTS ALOFT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 300 AM EDT MONDAY...ON THURSDAY MORNING AND UPPER RIDGE WILL BE
CENTERED OVER SW FL...EXTENDING N TO THE GREAT LAKES...WHILE TROUGHS
WILL BE OFF THE WEST AND EAST COASTS. A WELL DEFINED SHORTWAVE WILL
BE MOVING ACROSS THE PLAIN AT THAT TIME. BY FRIDAY MORNING THE
SHORTWAVE CROSSES THE UPPER MS RIVER VALLEY...AND BY SATURDAY
MORNING IT WEAKENS OVER THE NORTHEAST. MEANWHILE...THE UPPER RIDGE
REMAINS FROM THE GULF TO THE GREAT LAKES...WHILE A CLOSED LOW MOVES
INLAND FROM THE CA COAST TO UT. BY SUNDAY THE RIDGE AXIS PROGRESSES
TO THE APPALACHIANS...WHILE THE UPPER LOW MOVES INTO WY...AND
ANOTHER UPPER LOW APPROACHES THE CA COAST.
AT THE SURFACE...HIGH PRESSURE WILL EXTEND FROM THE GREAT LAKES TO
THE EAST COAST AND GULF STATES THURSDAY MORNING...WHILE A STATIONARY
FRONT EXTENDS FROM N FL TO THE GULF COAST. ON FRIDAY THE SURFACE
RIDGE WILL BE OVER THE EASTERN SEABOARD...WHILE GULF INFLOW SETS UP
TO THE WEST. ISENTROPIC UPGLIDE OVER THE SURFACE RIDGE WILL SUPPORT
PRECIPITATION OVER OUR AREA...BUT INSTABILITY APPEARS TO BE LACKING
AT THIS TIME.
THE SURFACE RIDGE MOVES OFF THE EAST COAST ON SATURDAY...ALLOWING
GULF INFLOW TO SPREAD EAST TOWARD THE SOUTHERN APPALACHIANS....AND
THIS PATTERN PERSISTS INTO SUNDAY. INCREASING INSTABILITY WILL
SUPPORT A RETURN OF THUNDERSTORMS...BUT AT THIS POINT SHEAR
APPEARS TO BE QUITE LIMITED...AND ORGANIZED CONVECTION UNLIKELY.
TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL RANGE DUE TO CLOUD COVER
AND INCREASING MOISTURE.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE (EXCEPT MTN VALLEYS)...VFR CONDITIONS ARE
GENERALLY EXPECTED UNTIL AFTERNOON...ALTHOUGH BRIEF MVFR VISBY WILL
BE POSSIBLE TOWARD DAYBREAK. IN FACT...THE POTENTIAL IS HIGH ENOUGH
TO INCLUDE TEMPOS FOR SUCH AT KAND/KHKY. OTHERWISE...SCT/BKN
STRATOCU IN THE 050-080 RANGE IS EXPECTED THROUGH MUCH OF THE
MORNING. THE PRIMARY CONCERN FOR THE FORECAST PERIOD WILL BE THE
POTENTIAL FOR DEEP CONVECTION LATER TODAY...WHICH SHOULD BE QUITE A
BIT HIGHER THAN IN RECENT DAYS. THIS IS DUE TO IMPROVING MOISTURE
AND INSTABILITY PROFILES. THERE IS STILL SOME QUESTION AS TO HOW
EXTENSIVE COVERAGE WILL BE...BUT PROB30S ARE CERTAINLY WARRANTED AT
ALL TERMINALS FROM MID-AFTERNOON ON. TEMPOS WILL NEED TO BE
ENTERTAINED FOR THE 12 TAFS...PARTICULARLY ACROSS AT KHKY AND THE
UPSTATE SC TERMINALS...AS THE MTNS AND NORTH GA APPEAR TO BE GROUND
ZERO FOR CONVECTIVE DEVELOPMENT LATER TODAY...WITH STEERING FLOW
PUSHING CELLS GRADUALLY TO THE EAST.
AT KAVL/MTN VALLEYS...THE MOST IMMEDIATE CONCERN IS THE POTENTIAL
FOR FOG/LOW STRATUS LATER THIS MORNING...WITH MVFR FOG ALREADY BEING
REPORTED IN THE VALLEYS SOUTHWEST OF KAVL. HOWEVER...AREAS OF VFR
STRATOCU AND THE POTENTIAL FOR OCCL LIGHT WINDS ARE CREATING SOME
DOUBTS ABOUT THE POTENTIAL AT KAVL. OPTED TO INCLUDE A TEMPO FOR
MVFR VISBY ALONG WITH SCT003 TOWARD DAYBREAK...BUT BRIEF IFR OR
WORSE CONDITIONS CANNOT BE RULED OUT. OTHERWISE...CONVECTION IS
EXPECTED TO DEVELOP OVER THE HIGH TERRAIN SURROUNDING THE MTN
TERMINALS BY EARLY AFTERNOON...AND A CATEGORICAL MENTION OF
SHRA/VCTS APPEARS WARRANTED BY MID-AFTERNOON.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING
ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE IN ON
WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE SOUTH...POSSIBLY
ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA LATE IN THE WEEK.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 85% HIGH 96% 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...JAT
NEAR TERM...JDL
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
403 AM CDT MON MAY 11 2015
.DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...
06Z TAFS
MAIN CORRIDOR OF TSRA WILL BEGIN AFFECTING THE JBR OVER THE NEXT
SEVERAL HOURS...AND ADVANCE EASTWARD TOWARD MEM AFTER 12Z. TSRA
WILL BECOME MORE LINEAR AND PERHAPS BETTER ORGANIZED ALONG AN
ADVANCING COLD FRONT. LATEST 00Z GUIDANCE SHOWS THE FRONTAL TIMING
MAY BE AN HOUR OR TWO QUICKER THAN EARLIER FORECAST...WITH TSRA
CHANCES AT MEM ENDING AS EARLY AS 18Z.
CLEAR SKIES AND LIGHT WINDS FOR THE LATE MONDAY EVENING ARRIVAL
PUSH.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
427 AM CDT MON MAY 11 2015
.SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...HIGH RIP CURRENT RISK UNTIL 6 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: ARANSAS...CALHOUN...KLEBERG...NUECES.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT EARLY THIS MORNING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
TB/78...SHORT TERM
LK/84...LONG TERM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
426 AM MDT MON MAY 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
DRIER DAY IN STORE FOR THE FORECAST AREA WITH TEMPS REBOUNDING
AFTER A COUPLE OF COOLER DAYS. HRRR AND NAM12 GENERATING A FEW
LATE DAY SHOWERS OVER THE HIGHER PEAKS...OTHERWISE IT WILL BE A
DRY DAY ACROSS THE REGION. QUIET PATTERN CONTINUES TONIGHT WITH
SHORTWAVE RIDGING SLIDING EAST INTO THE PLAINS. THIS ALLOWS FOR A
QUICK RETURN TO SOUTHERLY FLOW WITH ANOTHER SURGE OF MOISTURE
WORKING NORTHWARD BY MIDDAY TUESDAY. PRECIPITABLE WATER VALUES
CLIMB TO OVER A HALF INCH ACROSS THE SOUTHERN MOUNTAINS BY LATE
TUESDAY AFTERNOON...SO POTENTIAL FOR LOCALLY HEAVY RAIN IS NOT OUT
OF THE QUESTION. MODELS ARE IN GOOD AGREEMENT WITH AT LEAST
SCATTERED CONVECTION FIRING OVER THE MOUNTAINS AND SOUTHERN
VALLEYS TUESDAY AFTERNOON AND EVENING AND HAVE RAMPED POPS UPWARD.
TEMPS WILL BE MARCHING TOWARD ABOVE NORMAL READINGS BY TUESDAY
AFTERNOON IN THE STRENGTHENING SOUTHERLY FLOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
SHOWERS LINGER TUESDAY EVENING BEFORE A PACIFIC NW WAVE SHUNTS
THE NORTHERLY PROGRESSING MOISTURE BACK TO OUR EAST...WITH GENERAL
DECREASE IN ACTIVITY THROUGH MIDDAY WEDNESDAY. DIURNAL HEATING AND
LINGERING LOW LEVEL MOISTURE SHOULD FIRE A FEW MORE SHOWERS AND
THUNDERSTORMS WEDNESDAY AFTERNOON AND AGAIN THURSDAY. ACTIVITY
PICKS UP IN EARNEST BY FRIDAY AS ANOTHER STRONG LOW PUSHES INTO
THE GREAT BASIN. DEEP SWLY FLOW TAPS MOISTURE OFF THE BAJA AND
LIFTS IT NORTHEAST INTO THE FOUR CORNERS EARLY FRIDAY...SPREADING
NORTH IN INCREASINGLY DIFLUENT PATTERN OVER THE FORECAST AREA.
THIS WILL TRIGGER FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS BY
FRIDAY AFTERNOON WITH ACTIVITY LIKELY TO CONTINUE THROUGH THE
WEEKEND AS THE LOW LIFTS NORTHEAST INTO WYOMING. LATEST RUNS ARE A
TAD BIT SLOWER AND DEEPER WITH THE LOW VERSUS EARLIER RUNS...BUT
CONFIDENCE IS FAIRLY HIGH WE WILL BE IN FOR ANOTHER WET END OF THE
WEEK. TEMPS WILL BE RUNNING ON THE PLUS SIDE OF NORMAL THROUGH
THURSDAY...WITH GRADUAL COOLING AS WE MOVE INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 425 AM MDT MON MAY 11 2015
VFR CONDITIONS EXPECTED THROUGH TONIGHT WITH ONLY ISOLATED
MOUNTAIN SHOWERS. NEAR SHOWERS...EXPECTED LOWERED CIGS AND GUSTY
WINDS TO NEAR 35 MPH. PATCHY FOG RESTRICTING VISIBILITY IFR CONDS
WILL ALSO BE POSSIBLE UNTIL 16Z THIS MORNING...MAINLY IN THE
VALLEYS.
&&
.HYDROLOGY...
ISSUED AT 425 AM MDT MON MAY 11 2015
MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES.
HOWEVER...A COMBINATION OF RECENT RAIN FALL AND MELTING MOUNTAIN
SNOW WILL BRING GRADUAL RISES OVER THE NEXT WEEK. A FEW SMALLER
STREAMS AND CREEKS WILL BE RUNNING NEAR BANKFULL.
THE UPPER YAMPA RIVER IS ALREADY AT BANKFULL AND WILL REMAIN NEAR
OR SLIGHTLY ABOVE BANKFULL THROUGH MUCH OF THIS WEEK.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JDC
LONG TERM...JDC
AVIATION...JDC
HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1050 AM EDT MON MAY 11 2015
.SYNOPSIS...
HIGH PRESSURE WELL OFFSHORE DRIFTS EAST THROUGH TONIGHT AS LOW
PRESSURE PASSES TO THE SOUTH AND EAST LATE TONIGHT. A COLD FRONT
APPROACHES TUESDAY...PASSING EAST TUESDAY NIGHT...FOLLOWED BY HIGH
PRESSURE. A WEAK LOW PRESSURE SYSTEM MAY AFFECT THE REGION OVER
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOUTHWESTERLY FLOW AROUND HIGH PRESSURE WELL TO THE EAST HAS
MARITIME TROPICAL AIR ADVECTING ACROSS SEAS SURFACE TEMPS IN THE
LOWER 50S. THUS FOG AND STRATUS PERSIST FOR THE SOUTH SHORE OF
LONG ISLAND. DENSE FOG SOUTH OF MONTAUK HIGHWAY AND ESPECIALLY FOR
OCEAN PARKWAY - SPECIAL WEATHER STATEMENT IN EFFECT.
OTHERWISE...BACKDOOR COLD FRONT OVER NORTH EASTERN MA AND REMNANTS
OF ANA NEARING NORFOLK.
A SHOWER OR THUNDERSTORM IS POSSIBLE NORTH AND WEST OF NYC WHERE
WEAK INSTABILITY WILL FORM. LI`S GET DOWN TO -2 C AND A FEW
HUNDRED JOULES OF CAPE ARE PRESENT. HAVE LEFT THIS OUT OF THE
FORECAST THOUGH AS RAP AND HRRR REMAIN ISOLATED WITH ACTIVITY AND
NARRE-TL HAS VERY LOW PROBABILITIES.
TEMPS WERE ADJUSTED SLIGHTLY...MAINLY IN COASTAL SECTIONS FOR
TRENDS WITH THE ONSHORE FLOW. TEMPERATURES SHOULD BE SIMILAR TO
SUNDAY`S HIGHS. LEANED TOWARD THE MUCH WARMER MAV GUIDANCE AND
RAISED A DEGREE OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE SHORTWAVE ASSOCIATED WITH THE REMNANT LOW OF ANA PASSES TO THE
SOUTH AND EAST FROM 06Z TO 12Z AND MAY BRING SOME SHOWERS AND
ISOLATED THUNDER MAINLY TO THE WATERS SOUTH OF LONG ISLAND...WITH
A CHANCE ACROSS EASTERN LONG ISLAND.
MEANWHILE THE UPPER TROUGH AND COLD FRONT SLOWLY APPROACH TONIGHT
AND PRECIPITATION WILL REMAIN WEST OF THE AREA UNTIL EARLY TUESDAY
MORNING WHEN THE CHANCE OF SHOWERS INCREASES. FORCING WITH THE
FRONT WILL BE MINIMAL ALONG WITH 400 TO 500 CAPE AND WEAK
INSTABILITY. SO WILL KEEP POPS MINIMAL AT SLIGHT CHANCE TO LOW
CHANCE. AGAIN LEANED TOWARD THE WARMER MAV GUIDANCE FOR LOWS AND
HIGHS.
DENSE FOG LIKELY RETURNS TO LONG ISLAND AND COASTAL CT THIS
EVENING...THOUGH WSW FLOW TOWARDS MORNING SHOULD CLEAR THINGS UP
QUICKLY ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN GENERAL AGREEMENT WITH MEAN NE TROUGHING THROUGH THE
MIDWEEK...GRADUALLY SLIDING OFFSHORE WITH MORE ZONAL UPPER FLOW FOR
LATE WEEK/WEEKEND.
SHORTWAVE ENERGY PIVOTS INTO THE NORTHEAST TUESDAY NIGHT...WITH
SURFACE COLD FRONT MOVING THROUGH TUESDAY EVENING...PUSHING ANY
LINGERING SHRA/TSRA ACTIVITY OFFSHORE.
SHORTWAVE CONTINUES TO DIG THROUGH THE NE ON WEDNESDAY WITH
SECONDARY COLD FRONT SLIDING THROUGH. ASSOCIATED SCT-BKN AFT
INSTABILITY CU LIKELY...WITH AN ISOLATED INSTABILITY SHRA POSSIBLE
TO DRIFT SE OFF THE HIGHER TERRAIN INTO AREAS WELL N&W OF NYC. MOST
NOTICEABLE WILL BE A CHANGE TO A MUCH DRIER AND COOLER AIRMASS IN
THE WAKE OF THE COLD FRONTS...WITH HIGHS ONLY IN THE 60S FOR MOST OF
THE REGION ACCOMPANIED BY A BREEZY NW WIND. WITH THE TUE FRONTAL
SYSTEM NOT LOOKING LIKE A WETTING RAIN PRODUCER...THE GUSTY AND DRY
COND ON WED MAY LEND TO POTENTIAL FIRE WEATHER CONCERNS.
CHILLY CONDITIONS WED NIGHT AS HIGH BUILDS IN FROM WEST. PATCHY
FROST POSSIBLE ACROSS INTERIOR LOWER HUD AND SOUTHERN CT AS WELL AS
PINE BARRENS OF LI IF WINDS DECOUPLE QUICK ENOUGH.
DRY...TRANQUIL...AND GRADUAL MODERATING TREND TO SEASONABLE TEMPS
THU INTO FRI AS HIGH PRESSURE BUILDS IN FROM THE WEST.
MODELS IN GENERAL AGREEMENT WITH SW US SHORTWAVE ENERGY EJECTING
INTO THE CENTRAL PLAINS LATE WEEK...AND THEN ROUNDING SOUTHERN
RIDGING BUT WEAKENING AS IT APPROACHES THE REGION FRI NIGHT/SAT. AT
THE SURFACE...POTENTIAL EXISTS FOR A RESULTANT WEAK SURFACE LOW TO
TRACK ACROSS THE REGION ON SAT. HAVE INCREASED POPS TO LOW CHANCE
FOR FRIDAY NIGHT AND SAT BASED ON INCREASED MODEL AGREEMENT ON THIS
SCENARIO.
EARLY INDICATIONS ARE FOR DRY AND NEAR SEASONABLE TEMPS ON SUNDAY AS
CANADIAN MARITIMES HIGH BUILDS INTO THE REGION FROM THE NE DUE TO AN
AMPLIFYING TROUGH OFF SE CANADA COAST.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS OFFSHORE THROUGH TONIGHT.
LINGERING MVFR CIGS IMPROVE TO VFR LATE THIS MORNING. ONLY
EXCEPTION IS AT KGON AND KISP WHERE IFR HAS HELD ON LONGER. THIS
SHOULD IMPROVE BY EARLY THIS AFTERNOON.
SW TO S WINDS AROUND 5 TO 10 KT THIS MORNING INCREASES TO 10-15
KT THIS AFTERNOON. GUSTS UP TO AROUND 20 KT FOR SOME TERMINALS
THIS AFTERNOON.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MVFR CIG 015-025 MAY BRIEFLY HOLD ON
THROUGH 16Z. AN OCCASIONAL GUST TO AROUND 20 KT POSSIBLE THIS
AFTERNOON.
KLGA FCSTER COMMENTS: START TIME OF GUSTS TO 20KT MAY BE OFF BY
+/- AN HOUR.
KEWR FCSTER COMMENTS: MVFR CIG 025-030 MAY BRIEFLY HOLD ON
THROUGH 16Z. START TIME OF GUSTS TO 20KT MAY BE OFF BY
+/- AN HOUR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: START TIME OF GUSTS TO 20KT MAY BE OFF BY
+/- AN HOUR.
KHPN FCSTER COMMENTS: MVFR CIG 025-030 MAY BRIEFLY HOLD ON
THROUGH 16Z.
KISP FCSTER COMMENTS: IFR CIG 005-009 MAY LINGER UNTIL 16Z.
IMPROVEMENT TO VFR MAY OCCUR SOONER THAN INDICATED IN TAF. AN
OCCASIONAL GUST TO 20 KT POSSIBLE THIS AFTERNOON.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUE...BCMG VFR BY NOON. ISO TSTM. WSW GUSTS 25KT.
.WEDNESDAY-FRIDAY...VFR. NW GUSTS 25KT WED.
&&
.MARINE...
DENSE FOG PERSISTS FOR THE WATERS SOUTH OF LONG ISLAND AS WARM
HUMID AIR MOVES OVER THE COLD SEA SURFACE. PATCHES OF CLEARING ARE
EXPECTED...BUT OVERALL...THE DENSE FOG REMAINS SIGNIFICANT AND THE
ADVISORY CONTINUES THROUGH THE MORNING.
OTHERWISE...SOUTHWESTERLY FLOW WILL PERSIST ACROSS THE FORECAST
WATERS TODAY AND TONIGHT AS HIGH PRESSURE OVER THE NORTHERN
ATLANTIC DRIFTS EAST. SEAS WILL BUILD TO SMALL CRAFT LEVELS
TONIGHT AS SWELLS FROM THE REMNANT LOW OF ANA PASSES TO THE SOUTH
AND EAST. IN ADDITION SOME GUSTS MAY APPROACH 25 KT. SMALL CRAFT
SEAS WILL REMAIN INTO TUESDAY ALONG WITH SOME GUSTY WIND TO NEAR
25 KT AS A COLD FRONT APPROACHES.
SCA CONDITIONS LIKELY ON THE OCEAN WATERS TUESDAY NIGHT FROM
RESIDUALS SCA SOUTHERLY SWELLS AND INCREASING OFFSHORE WINDS IN WAKE
OF COLD FRONT. MARGINAL SCA GUSTS ARE POSSIBLE ON ALL WATERS TUE
NIGHT IN WAKE OF COLD FRONT...BUT BETTER CHANCE ON ALL NEARSHORE
WATERS ON WEDNESDAY. SCA SWELLS GRADUALLY SUBSIDE ON THE OCEAN WED
INTO WED NIGHT.
SUB SCA CONDS LIKELY THU AND FRI AS HIGH PRESSURE BUILDS OVER THE
WATERS.
&&
.HYDROLOGY...
NO SIGNIFICANT WIDESPREAD RAINFALL IS EXPECTED THROUGH FRIDAY.
A FEW LOCALLY HEAVIER SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TUESDAY WITH BASIN AVERAGE QPF LESS THAN A QUARTER INCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT TUESDAY FOR ANZ345-350-353-
355.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MET/NV
NEAR TERM...MET/TONGUE
SHORT TERM...MET
LONG TERM...NV
AVIATION...JC/DS
MARINE...MET/NV
HYDROLOGY...MET/NV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
928 AM EDT MON MAY 11 2015
.DISCUSSION...
TODAY...EARLY MORNING VISIBLE SATELLITE IMAGERY SHOWED ATLANTIC
CLOUDS DENOTING LOW LEVEL RIDGE AXIS VICINITY OF CAPE CANAVERAL.
THIS NORTHWARD SHIFT OF THE HIGH PRESSURE RIDGE WILL BRING GRADIENT
WINDS OUT OF THE SOUTHEAST FOR THE SPACE/TREASURE COAST.
HIGHER MOISTURE WAS NOTED ON THE MORNING SOUNDINGS SO EXPECT A
SLIGHTLY HIGHER COVERAGE OF SHOWERS/STORMS. HOWEVER...A MORE RAPID
INLAND ADVANCE OF THE SEA BREEZE WILL OCCUR...SO THE SPACE/TREASURE
COAST WILL HAVE A BRIEF WINDOW FOR INLAND STORM CHANCES. COASTAL
VOLUSIA WILL HAVE A SLIGHTLY SLOWER INLAND SEA BREEZE MOTION SO
ISOLATED COVERAGE SHOULD OCCUR CLOSER TO THE COAST THERE.
THE HRRR MODEL HAS BEEN SHOWING SCATTERED COVERAGE FROM NEAR THE
KISSIMMEE RIVER IN OKEECHOBEE COUNTY TO ORLANDO...LAKE GEORGE AND
POINTS WESTWARD. THIS IS IN AGREEMENT WITH OUR FORECAST SO DO NOT
PLAN ANY CHANGES.
TEMPS ALOFT ARE RATHER COOL COOL WITH 500MB AROUND -10 DEGREES
CELSIUS AND THERE IS ALSO SOME DRY MID LEVEL AIR. SO WITH DAYTIME
HEATING INTO THE LOWER 90S INLAND...THE STRONGEST BOUNDARY
COLLISIONS WILL BE CAPABLE OF GENERATING ISOLATED STRONG STORMS.
THIS WOULD MOST LIKELY BE WHERE THE EAST/WEST COAST BOUNDARIES
COLLIDE OVER SOUTH LAKE COUNTY OR JUST TO THE WEST OF THERE DURING
THE EVENING.
&&
.AVIATION...PREVIOUS DISCUSSION STILL VALID
THE EAST COAST SEA BREEZE WILL MOVE INLAND FASTER TODAY WITH A
CHANCE FOR STORMS OVER THE NORTH/INTERIOR TERMINALS...KSFB-KMCO-KISM-
KLEE. PLAN TO CONTINUE USING VCTS IN THE TAFS FOR NOW SINCE PROBS
ARE ONLY AROUND 30 PERCENT. THE SEA BREEZE SHOULD BE STRONG THIS
AFTN WITH E/SE FLOW 15-20 KNOTS WITH SOME HIGHER GUSTS MLB-SUA.
&&
.MARINE...
TODAY...LITTLE CHANGE TO PREVIOUS THINKING. WINDS NEAR SURFACE HIGH
PRESSURE RIDGE AXIS VICINITY CANAVERAL-BUOY 41009 WERE
LIGHT/VARIABLE.
SOUTH OF THERE...SOUTHEAST GRADIENT WINDS WILL BE PICKING UP TO 10-
15 KNOTS. NORTHERN WATERS MIGHT NOT SEE THOSE SPEEDS WITH THE RIDGE
AXIS REMAINING NEARBY.
ISOLATED MARINE SHOWERS WILL OCCUR WITH A MORE MOIST REGIME IN
PLACE. A FEW STORMS COULD OCCUR NEAR THE GULF STREAM FROM CANAVERAL
NORTHWARD INTO EARLY AFTERNOON.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
654 AM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 653 AM CDT MON MAY 11 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 653 AM CDT MON MAY 11 2015
BAND OF RAIN AND EMBEDDED THUNDERSTORMS IS EXPECTED TO DISSIPATE
OR BECOME MORE SCATTERED AS IT MOVES SLOWLY EAST THROUGH 18Z. A
PERIOD OF MVFR CONDITIONS IS POSSIBLE AS THE PRECIPITATION MOVES
THROUGH EACH SITE. CONFINED THE TS AND MVFR CONDITIONS TO A 2 HOUR
PERIOD. SOME LOW VFR CEILINGS ARE LIKELY FOR A FEW HOURS BEHIND
THE RAIN...AND MVFR CEILINGS CANNOT BE RULED OUT.
SOUTH WINDS WILL INCREASE AND VEER TO WEST SOUTHWEST THROUGH THE
DAY. SUSTAINED WINDS IN THE TEENS AND GUSTS WELL INTO THE 20S ARE
EXPECTED...WITH THE STRONGEST WINDS AT KOWB. SKIES WILL CLEAR
QUICKLY EARLY THIS EVENING...AND WINDS WILL SUBSIDE TO UNDER 10KTS
WITH SUNSET.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...RJP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS JACKSON KY
642 AM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 642 AM EDT MON MAY 11 2015
VFR CONDITIONS WILL BE SEEN TO START THE FORECAST PERIOD.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE NOW EXPECTED
TO DEVELOP BETWEEN 16Z AND 23Z...WHICH IS AN EARLIER ONSET THAN
PREVIOUSLY EXPECTED. THIS NEW TIMING WILL BE REFLECTED IN THE 12Z
TAFS. AS MENTIONED BEFORE...GUSTY WINDS ARE EXPECTED IN AND AROUND
ANY THUNDERSTORMS THIS AFTERNOON ALONG WITH THE THREAT OF
TURBULENCE. VFR CONDITIONS SHOULD DOMINATE THOUGH...BUT SOME
REDUCED VISIBILITIES ARE POSSIBLE IN THE STRONGER STORMS. VFR
CONDITIONS WILL RETURN BY LATE EVENING...BUT WILL NEED TO WATCH
FOR FOG OR LOW CLOUD DEVELOPMENT PENDING RAINFALL AMOUNTS AND
WHERE THE RAIN FALLS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
644 AM CDT MON MAY 11 2015
.AVIATION...THE HIGH RESOLUTION SHORT RANGE MODEL TAKES THE BAND
OF SHOWERS AND THUNDERSTORMS APROACHING FROM THE NORTHWEST INTO
THE TERMINALS LATER THIS MORNING. POSSIBLE CONDITIONS AS LOW AS
LIFR CIGS WITH RAIN ASSUMING THE CURRENT ACTIVITY WEAKENS AS SOME
SIGNS HAVE INDICATED. SINCE ATMOSPHERE WOULD BE WORKED OVER BY THIS
AFTERNOON WILL GO WITH VFR CIGS WITH VCTS. LATE TNITE AS THE WEAK
FRONT APPROACHES, MVFR WITH LIGHT RAIN.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 343 AM CDT MON MAY 11 2015/
DISCUSSION...MAIN FORECAST ISSUE WILL BE POPS THROUGHOUT THE
WEEK.
LINE OF THUNDERSTORMS OVER NE TEXAS HAS SLOWLY SHIFTED SE DURING THE
NIGHT. LATEST HRRR MAY BE A LITTLE QUICK IN PUSHING THE LINE INTO
NW PART OF THE FORECAST AREA BY 12Z...BUT THERE IS CERTAINLY
POTENTIAL FOR CONVECTION DEVELOPING AHEAD OF THE LINE BY THAT
TIME. EVEN IF LINE WEAKENS...REMNANT BOUNDARIES COMBINED WITH
RICH THTE AIR WILL LIKELY KEEP GOOD COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR TODAY ESPECIALLY ACROSS EAST TEXAS AND CENTRAL
LOUISIANA. WILL TWEAK CURRENT POPS FORECAST FOR TODAY BUT OVERALL
NOT MUCH CHANGE FROM PREVIOUS FORECASTS.
FOR TUESDAY...MODELS SHOW VIGOROUS SHORTWAVE IN UPPER SW FLOW AND
THIS SHOULD FURTHER ENHANCE SHOWER AND THUNDERSTORM CHANCES.
A SERIES OF UPPER SHORT WAVE TROUGHS WILL MOVE THROUGH THE
WESTERN U.S. THROUGH THE WEEK. ALSO...MODELS ARE SHOWING A BROAD
NEGATIVELY TILTED TROUGH BECOMING ESTABLISHED OVER THE WEST COAST
BY LATE IN THE WEEK. AT THE SURFACE...FRONTAL BOUNDARY IS
FORECASTED TO MOVE INTO THE AREA AND STALL THROUGH AT LEAST
WEDNESDAY. A VERY MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE
WEEK. WILL THEREFORE MAINTAIN MAINLY DIURNAL SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK. WILL LOWER POPS
SLIGHTLY OVER THE WEEKEND AS SURFACE BOUNDARY SHOULD BE LESS
DEFINED OR DIFFUSE.
MARINE....WILL ALLOW SCEC TO EXPIRE AT 5 AM FOR INNER AND OUTER
WATERS. WITH BOUNDARY APPROACHING THE AREA ON TUESDAY...GRADIENT
SHOULD WEAKEN AND LOW LEVEL FLOW SHOULD BECOME MORE EASTERLY.
PROGRESSION OF HIGH PRESSURE TOWARD THE EAST COAST WILL ALLOW FOR
A WEAK SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEK.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 84 68 79 65 / 60 70 70 30
LCH 83 71 83 70 / 50 50 70 30
LFT 86 72 84 70 / 40 40 60 30
BPT 83 72 82 71 / 50 60 70 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...11
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1043 AM EDT MON MAY 11 2015
.SYNOPSIS...
VERY WARM WEATHER WILL CONTINUE TODAY UNTIL THE PASSAGE OF A
COLD FRONT OVERNIGHT. THUNDERSTORM CHANCES WILL INCREASE THIS
AFTERNOON AND TONIGHT AS THE FRONT APPROACHES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE WAS TO TRY TO PINPOINT TIMING OF EXPECTED CONVECTIVE
ACTIVITY LATER TODAY. HRRR RUNS SEEM TO HAVE A GOOD HANDLE ON
CURRENT ACTIVITY AND HAVE BEEN FAIRLY CONSISTENT IN BRINGING
ACTIVITY TO NEAR ZZV BY 22Z AND TO THE PA/WV BORDER BY 00Z.
MIDLEVEL WINDS DO INCREASE INTO THE 40-50 KNOT RANGE AROUND 00Z IN
OHIO...AND EXPECTED INVERTED-V SOUNDINGS INDICATE SOME DOWNDRAFT
POTENTIAL AS WELL. SPC HAS OHIO OUTLOOKED IN SLIGHT RISK AREA AND
THIS LOOKS REASONABLE AS A FEW STRONG TO DAMAGING WIND GUSTS
APPEAR POSSIBLE. ADDED GUSTY WIND WORDING TO GRIDS/ZFP. MOST OTHER
CHANGES AMOUNTED TO TWEAKS. CL
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH THE FRONT TIMED TO APPROACH THIS EVENING...WE WILL LOSE THE
INSTABILITY NEEDED FOR A STRONG ORGANIZED LINE OF STORMS TO
CONTINUE. ADDITIONALLY...AS THE FRONT IS NOT MUCH MORE THEN A
RIPPLE IN ISOBARS WITH ONLY WEAK COLD AIR ADVECTION BEHIND IT AND
A MINOR SHIFT IN SURFACE WINDS. I WOULD EXPECT A LINE OF SHOWERS
AND STORMS TO ROLL THROUGH WITH THIS FEATURE...BUT SEE THE
ACTIVITY WEAKENING AS IT RUSHES TO THE EAST.
UPPER TROUGH WILL PIVOT A SECONDARY FRONT...TIED TO A MUCH COOLER
AIRMASS...THROUGH THE REGION BY LATE TUESDAY MORNING. WILL NEED TO
KEEP IN THE CHANCE FOR SHOWERS AND POSSIBLY A STORM UNTIL THIS
BOUNDARY CROSSES. TEMPERATURES MAY ACTUALLY STAY ELEVATED UNTIL
THIS BOUNDARY PASSES...WITH HIGH TEMPERATURE BEING REALIZED EARLY
BEFORE A GRADUAL DECLINE IS EXPECTED. THE DOWNWARD TREND SHOULD
CONTINUE TUESDAY NIGHT AND WEDNESDAY AS THE GREAT LAKES REGION
REMAINS IN NORTHWEST FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
QUIET AND COOL BEGINNING TO THE LONG TERM PERIOD. TEMPERATURES
WILL MODERATE BY THE END OF THE WEEK AND THROUGH THE WEEKEND.
LOOKS TO BE A MORE ACTIVE WEATHER PATTERN SETTING UP FOR SATURDAY
AND SUNDAY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE AFTERNOON WITH INCREASING
MID-LEVEL CLOUD COVERAGE AHEAD OF AN APPROACHING COLD FRONT.
THUNDERSTORM CHANCES WILL INCREASE THROUGH THE AFTERNOON AND LAST
THROUGH MIDNIGHT...WITH TWO PRIMARY TIMEFRAMES WHERE CHANCES WILL
BE GREATEST. FIRST BETWEEN LATE AFTERNOON AND EARLY EVENING WITH
THE PASSAGE OF A SHORTWAVE TROUGH ALOFT...AND SECOND WITH THE
PASSAGE OF A WEAK COLD FRONT SHORTLY BEFORE MIDNIGHT INTO EARLY
TUESDAY MORNING.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS IS EXPECTED WITH MID WEEK
MORNING FOG AND STRATUS AS COOLER AIR SETTLES OVER THE REGION IN
THE WAKE OF THE FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1115 AM EDT MON MAY 11 2015
LATEST UPDATE...
UPDATE/MARINE
.SYNOPSIS...
ISSUED AT 320 AM EDT MON MAY 11 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY WITH SOME SEVERE
WEATHER POSSIBLE IN THE FORM OF DAMAGING WIND GUSTS AND PERHAPS
ISOLATED TORNADOES. A COLD FRONT MOVES IN TONIGHT BRINGING VERY
CHILLY AIR FOR TUESDAY WITH HIGHS ONLY IN THE 50S ALONG WITH GUSTY
WESTERLY WINDS. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY
BUT MORE PRECIP IS POSSIBLE FOR LATE IN THE WEEK AND PORTIONS OF
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
I UPDATED THE GRIDS TO SHOW A MORE REALIST PROGRESSION OF THE
CONVECTION THAT EXPECTED TO MOVE THROUGH THE AREA THIS AFTERNOON
AHEAD OF THE COLD FRONT. I ALSO DROPPED THE FOG ADVISORY AND
REPLACED IT WITH AREAS OF FOG INTO EARLY AFTERNOON BUT FOR THE
MOST PART THE FOG IS GONE.
AS FOR THE SEVERE WEATHER THREAT... CLEARLY CLOUD COVER IS AN
ISSUE. THAT WOULD DECREASE THE THREAT FOR STRONG TO SEVERE STORMS
OVER OUR CWA THIS AFTERNOON. EVEN SO THE LATEST RAP MODEL...WHICH
IS DONE WELL WITH THE CURRENT AREA OF SHOWERS AND WHERE THE
CURRENT THUNDERSTORMS ARE...SHOWS MAX WIND SPEED CORE ON THE LOW
LEVEL JET DEVELOPING OVER WRN IN AND SOUTHWEST LWR MI BY NOON BUT
AT THAT POINT WINDS ARE MOSTLY UNDER 35 KNOTS. BY 4 PM THE RAP 14Z
MODEL SHOWS A CORE OF 40 KNOT WINDS ON THE LOW LEVEL JET NEAR JXN
MOVING NORTHEAST...REACHING THE FNT AREA BY EARLY EVENING. AT THE
SAME TIME THE ENTRANCE REGION TO A 110 KNOT 300 MB JET IS MOVING
NORTH NORTHEAST ACROSS LAKE MICHIGAN. THE PUTS MOST OF SOUTHWEST
MICHIGAN IN A FAVORABLE PLACE FOR STRONG TO SEVERE THUNDERSTORMS.
THE MOST UNSTABLE CAPE (OVER 500 J/KG) STAYS SOUTH OF A LINE FROM
AZO TO LAN TO FNT. THIS TELLS ME THE THREAT FOR STRONG TO SEVERE
STORMS IS MOSTLY IN THE I-69 AREA (MORE OR LESS) DURING THE MID
AFTERNOON. ELSESWHERE WILL LIKELY SEE SHOWERS AND
THUNDERSTORMS... WITH A LESSER THREAT FOR STRONG TO SEVERE STORMS.
ALSO THIS TELLS ME THE GREATEST THREAT IS FOR DAMAGING WINDS SINCE
THE CAPE IS NOT ALL THAT GREAT IN THE -10 TO -30C RANGE ON THE
LATEST RAP MODEL SOUNDINGS NEAR JXN AND LAN.
UPDATE ISSUED AT 626 AM EDT MON MAY 11 2015
WILL BE ISSUING A DENSE FOG ADVISORY SHORTLY FOR THE TWO ROWS OF
COUNTIES NORTH OF THE I94 ROW. FEEL THAT CONDITIONS ARE IMPROVING
AND WILL CONTINUE TO IMPROVE ALONG I94...SO LEFT THAT ROW OUT OF
THE DENSE FOG ADVISORY FOR THE TIME BEING. THE DENSE FOG ADVISORY
WILL INCLUDE HOLLAND...GRAND RAPIDS...LANSING AND HASTINGS. THE
FOG IS MOST THICK JUST NORTH OF THE WARM FRONT WHICH IS LIFTING
NORTH. THE WARM FRONT AT 600AM WAS LOCATED ALONG I94 LIFTING
NORTH. OB SITES IN THE FAR SOUTHERN ROW OF COUNTIES ALONG THE
MI/IN LINE HAVE IMPROVED SUBSTANTIALLY WITH THIS TREND MOVING
NORTH. THE ADVISORY WILL RUN THROUGH 11AM.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
FORECAST CONCERNS DEAL WITH THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY THIS AFTERNOON AND EVENING. OVERALL...THERE LOOKS TO BE A MAIN WINDOW
OF OPPORTUNITY FROM 17Z TO 00Z FOR ANY SEVERE WEATHER...WITH THE PRIMARY THREAT
BEING DAMAGING WIND GUSTS AND A SECONDARY CONCERN BEING ISOLATED TORNADOES.
MANY INGREDIENTS ARE COMING TOGETHER TODAY TO SUPPORT THE CONTINUED THREAT FOR
SEVERE THUNDERSTORMS IN SPITE OF AN ENVIRONMENT THAT WILL FEATURE ONLY MODEST
CAPE. GOOD POSITIONING WITH RESPECT TO THE UPPER LEVEL JET (STRONGER DIVERGENCE
SHOWN TO OVERSPREAD THE SOUTHERN AND EASTERN CWA BY 18Z) ALONG WITH MID LEVEL
VORT LOBES AND A STRONG LLJ OF 50 KTS ACROSS NORTHERN INDIANA ARE THE MAIN
SYNOPTIC FEATURES OF NOTE. SPEAKING OF THE LLJ...THERE LOOKS TO BE DECENT WIND
CONVERGENCE AT THE NOSE OF THE JET ACROSS SW AND S CENTRAL LOWER MI. MOISTURE
POOLING AND CONVECTIVE DEVELOPMENT LOOK LIKELY ACROSS A GOOD PORTION OF THE
CWA...INCLUDING BUT NOT LIMITED TO WHERE THE SLIGHT RISK AREA IS OUTLINED
FOR TODAY.
WHILE SFC BASED CAPE WILL BE REALIZED AS THE WARM FRONT PUSHES NORTH TODAY...IT
WILL NOT BE SUBSTANTIAL...ONLY ON THE ORDER OF A FEW HUNDRED JOULES/KG MAINLY
FROM I-96 TO THE SOUTH. HOWEVER...COMPENSATING FOR THE MARGINAL INSTABILITY
WILL BE STRONG LOW LEVEL WIND SHEAR AND ELEVATED STORM RELATIVE
HELICITY...WHICH INTRODUCES A THREAT FOR ISOLATED TORNADOES. GFS BUFKIT
SOUNDING FOR AZO AT 18Z SHOWS 0-2KM SHEAR OF AROUND 45 KTS AND 0-1KM SRH OF 235
M2/S2. THE SPC SREF SIG TOR PARAMETER SHOWS A 30% PROBABILITY OF >=1 FOR OUR
SOUTH CENTRAL CWA.
THE CONVECTION ALLOWING MODELS SUPPORT A LINEAR LINE BEING THE PRIMARY
CONVECTIVE MODE...WITH SOME SUGGESTION THAT A FEW DISCRETE CELLS COULD FIRE
AHEAD OF THE LINE ESPECIALLY EAST OF A AZO TO LAN LINE. THE NSSL WRF AND HRRR
BOTH SUGGEST A LINEAR LINE OF STORMS MOVING FROM NORTHERN INDIANA INTO SW LOWER
MI LATE MORNING/EARLY AFTERNOON...AND PROGRESSING EAST QUITE RAPIDLY. THIS LINE
OF STORMS WILL LIKELY BE PRE-FRONTAL WITH A MORE NARROW LINE OF CONVECTION
FOLLOWING FOR LATE IN THE AFTERNOON AND EARLY EVENING...MARKING THE ARRIVAL OF
THE COLD FRONT.
CHILLY TEMPS ON TUESDAY IN THE MIDST OF CAA WILL MAKE FOR A RATHER
FALL-LIKE DAY. GUSTY WINDS ARE FORECAST TO BE 20 TO 30 MPH OR
PERHAPS GREATER AT TIMES...MAKING IT FEEL EVEN COLDER THAN THE
50S. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
EXTENDED PERIOD LOOKS TO FEATURE NEAR TO ABOVE NORMAL TEMPERATURES
AND POTENTIALLY WET WEATHER. THE UPPER PATTERN WILL START WITH
RIDGING IN PLACE MID WEEK...WHICH WILL TREND TO A DEEP SOUTHWEST
FLOW LATE IN THE WORK WEEK AND INTO NEXT WEEKEND.
TWO MAIN WEATHER FEATURES TO KEEP AN EYE ON. FIRST IS A SHORTWAVE
THAT MOVES THROUGH THE REGION THURSDAY NIGHT AND FRIDAY. HAVE
SHOWERS IN THE FORECAST BOTH PERIODS. AT THIS POINT JUST CHANCE
POPS...BUT COULD SEE NEEDING TO BUMP THIS UP WITH TIME.
THE NEXT ITEM OF NOTE WILL BE OVER THE WEEKEND AS A WARM FRONT SETS
UP OVER THE GREAT LAKES AHEAD OF A LOW IN THE PLAINS. WE COULD SEE
PERIODS OF SHOWERS AND STORMS DURING THIS TIME FRAME.
HIGHS WILL START THE PERIOD IN THE 60S ON THURSDAY...BUT WARM INTO
THE 70S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 746 AM EDT MON MAY 11 2015
LIFR CONDITIONS ARE WIDESPREAD AT THE TAF SITES AT 12Z. A WARM
FRONT IS PUSHING NORTH FROM THE INTERSTATE 94 CORRIDOR WITH MUCH
IMPROVED CONDITIONS TO THE SOUTH OF IT...VFR. CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH THE COURSE OF THE MORNING...AT LEAST
TO MVFR IF NOT VFR FOR A SHORT TIME AS THE WARM FRONT LIFTS
NORTHWARD.
THIS AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD MOVE INTO THE
AREA FROM THE SOUTHWEST. AT THIS POINT HAVE VCTS WORDING. THE
EARLY AFTERNOON SET OF TAFS MAY BE ABLE TO PROVIDE BETTER TIMING
IN REGARD TO THE PRECIPITATION. MOST LIKELY MVFR MUCH OF THE
AFTERNOON WITH CEILINGS AND POTENTIALLY VISIBILITIES.
THE SHOWERS...STORMS AND POOR AVIATION CONDITIONS SHOULD SWEEP
EAST THIS EVENING. THERE IS A CHANCE THAT MVFR CEILINGS COULD
REDEVELOP OVERNIGHT...BUT KEPT THINGS VFR AT THIS POINT.
&&
.MARINE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
LOOKING AT WEB CAMS FOG DOES NOT SEEM TO BE MUCH OF AN ISSUE OVER
THE NEAR SHORE SO I DISCONTINUED THE DENSE FOG ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1242 PM EDT SUN MAY 10 2015
MOST AREAS HAVE RECEIVED BETWEEN 1 AND 1.5 INCHES OF RAIN SINCE
THURSDAY. THIS HAS BEEN STEADY ENOUGH TO KEEP RIVER RESPONSE QUITE
GENTLE SO FAR. THERE IS STILL A FAIR CUSHION BEFORE BANKFULL IS
REACHED AT MOST LOCATIONS.
AN ADDITIONAL 0.5 TO 0.75 INCHES OF RAIN IS EXPECTED THROUGH MONDAY
EVENING. AFTER THIS DRY CONDITIONS SHOULD PREVAIL THE REST OF THE
WORK WEEK. THIS WILL RESULT IN ADDITIONAL MODEST WITHIN BANK RISES
FOR MOST RIVERS AND STREAMS. THE AREAS MOST VULNERABLE TO
SIGNIFICANT RISES UNDER THE HEAVIEST RAIN INCLUDE THE GRAND RIVER AT
JACKSON AND THE HEADWATERS OF THE KALAMAZOO RIVER.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
759 AM EDT MON MAY 11 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL SHIFT OFF THE EAST COAST
TODAY. A SHARP COLD FRONT WILL CROSS CENTRAL PA EARLY
TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING
SOUTHEAST INTO PA FOR THE SECOND PART OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR LOOP SHOWING SCT CONVECTION WORKING INTO THE NW
MTNS AT 09Z IN ASSOC WITH A WEAK SHORTWAVE RIDING ALONG NW
PERIPHERY OF UPPER RIDGE. HRRR SUPPORTS A CONTINUING CHC OF A
SHRA ACROSS THE NW MTNS THRU ARND 12Z...THEN A DIMINISHING CHC OF
PRECIP AFTER 12Z...AS SHOWERS RUN INTO A MORE UNFAVORABLE
ENVIRONMENT BENEATH UPPER RIDGE OVR CENTRAL PA. ACROSS EASTERN
PA...MARINE STRATUS DECK...WHICH COVERS AREAS EAST OF THE SUSQ
RIVER AT 0930Z...SHOULD MIX OUT TO SCT-BKN CU BY LATE AM.
AS RIDGE AXIS SLIDES EAST...PLUME OF HIGHER PWATS WILL OVERSPREAD
THE REGION TODAY. THE INCREASED HUMIDITY/INSTABILITY...COMBINED
WITH PASSAGE OF A WEAK MID LVL VORT MAX...SHOULD SUPPORT SCT PM
TSRA...ESP ACROSS THE CENTRAL MTNS. AN EXAMINATION OF MDL
SOUNDINGS SHOWS MODERATE CAPE OF ARND 1500 J/KG AND WEAK
SHEAR...IMPLYING MOSTLY PULSE TYPE CONVECTION W/LITTLE RISK OF
ORGANIZED SVR WX. MDL 8H TEMPS SUPPORT HIGHS IN THE L/M80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
BULK OF MDL DATA SUPPORTS A LULL IN CONVECTIVE ACTIVITY THIS
EVENING BTWN SCT DIURNALLY-DRIVEN ACTIVITY LATE THIS AFTN AND
ARRIVAL OF SHARP COLD FRONT LATE TONIGHT. ALL MDL DATA TRACKS COLD
FRONT THRU MOST OF CENTRAL PA BTWN 06Z-12Z TUESDAY...LIKELY
SPARING THE AREA SVR WX. IN ADDITION...PARENT SHORTWAVE AND BULK
OF LG SCALE FORCING IS PROGGED TO PASS WEST OF PA THRU THE GRT
LKS. HAVE PLACED THE HIGHEST /LKLY/ POPS ACROSS THE NW MTNS
TONIGHT AND THE LOWEST CHC OF RAIN ACROSS THE SE
COUNTIES...FURTHEST FROM UPPER LVL SUPPORT. TONIGHT WILL LIKELY BE
THE WARMEST NIGHT OF OUR RECENT STRING OF WARM NIGHTS...DUE TO
SURGING LOW LVL MOISTURE AND INCREASING CLOUD COVER.
TUESDAY WILL BE A DRY AND WINDY DAY FOR MOST OF CENTRAL PA BEHIND
COLD FRONT...AS STRENGTHENING PARENT LOW PASSES NORTH OF PA.
BUFKIT SOUNDINGS SUPPORT WGUSTS TO ARND 30KTS. AN ADDITIONAL
-SHRA IS POSSIBLE IN A FEW SPOTS TUES AFTN WITH PASSAGE OF UPPER
LVL TROF AXIS. HOWEVER...PTSUNNY AND DRY WX EXPECTED FOR MOST.
ENS MEAN 8H TEMPS STILL INDICATE TEMPS ABOVE NORMAL WITH MAX
READINGS LIKELY RANGING FROM THE U60S OVER THE NW MTNS...TO THE
L80S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER TROF AND COOL TEMPS ALOFT WILL REMAIN OVR PA
WED...LKLY RESULTING IN A GOOD DEAL OF AFTN CU/STRATOCU...ESP OVR
THE MTNS. 8H TEMPS SUPPORT HIGHS ONLY IN THE 50S TO L60S. THURSDAY
MORNING COULD BE QUITE CHILLY...AS SFC HIGH BUILDS OVER THE AREA.
MAY HAVE TO CONTEND W/POSSIBLE FROST OVR THE NW MTNS THOSE
MORNINGS WITH MINS LKLY IN THE 30S. GROWING SEASON STARTS MAY 11
OVER PARTS OF THE ALLEGHENY MTNS. CONFIDENCE IN NEAR-FREEZING
TEMPS IS HIGHEST IN MCKEAN/POTTER AND ELK BUT THE GROWING SEASON
DOES NOT BEGIN IN THESE COUNTIES UNTIL MAY 21.
BY LATE NEXT WEEK...ALL MED RANGE GUIDANCE SHOWS UPPER LVL RIDGE
REBUILDING ACROSS THE GRT LKS. HAVE INTRODUCED THE CHC OF SHOWERS
LATE FRIDAY/SATURDAY...WHEN MDLS SHOW A SHORTWAVE CRESTING RIDGE
AND DIVING SE TOWARD PA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AN UPPER LEVEL RIDGE WILL SHIFT OFF THE EAST COAST TODAY. A SHARP
COLD FRONT WILL CROSS CENTRAL PA EARLY TUESDAY...FOLLOWED BY A
LARGE HIGH PRESSURE SYSTEM FOR MIDWEEK.
UPPER LEVEL RIDGE BEGINNING TO GRADUALLY BREAK DOWN OVER THE
REGION TODAY. VFR CONDITIONS IN PLACE FOR MUCH OF CWA...WITH
MARINE LAYER STRATUS/FOG DECK IMPACTING THE SUSQ VALLEY FROM KIPT
TO KMDT-KLNS WITH MVFR CIGS. THIS SHOULD MIX OUT THROUGH THE MID
MORNING...LINGERING LONGEST AT KMDT-KLNS.
BY AFTERNOON...LOW LEVEL MOISTURE WILL BE INCREASING AS A WEAK MID
LEVEL SHORTWAVE SLIDES THROUGH. THIS WILL BE ENOUGH TO INITIATE
SCT SHOWERS / ISO TSTMS ACROSS THE WEST...WITH ONLY ISOLATED
CONVECTION POSS IN CENTRAL/EASTERN SECTIONS.
AFTER A LULL DURING THE EVENING...SHARP COLD FRONT MOVES THROUGH
OVERNIGHT KICKING OFF ANOTHER ROUND OF SCT/NUM SHOWERS AND ISO
TSTMS...MAINLY FOR WESTERN AND CENTRAL MTNS. TIMING OF FRONT COULD
ALLOW THE MARINE LAYER STRATUS TO RETURN IN THE LOWER SUSQ. AND
BEHIND THE FRONT MVFR CIGS WILL SLIDE INTO KBFD-KJST AS SW/W WINDS
BECOME BREEZY.
OUTLOOK...
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
FRI...MVFR WITH SCT SHRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
613 AM EDT MON MAY 11 2015
.SYNOPSIS...
AN ANOMALOUS UPPER LEVEL RIDGE WILL SHIFT OFF THE EAST COAST
TODAY. A SHARP COLD FRONT WILL CROSS CENTRAL PA EARLY
TUESDAY...FOLLOWED BY A LARGE HIGH PRESSURE SYSTEM BUILDING
SOUTHEAST INTO PA FOR THE SECOND PART OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR LOOP SHOWING SCT CONVECTION WORKING INTO THE NW
MTNS AT 09Z IN ASSOC WITH A WEAK SHORTWAVE RIDING ALONG NW
PERIPHERY OF UPPER RIDGE. HRRR SUPPORTS A CONTINUING CHC OF A
SHRA ACROSS THE NW MTNS THRU ARND 12Z...THEN A DIMINISHING CHC OF
PRECIP AFTER 12Z...AS SHOWERS RUN INTO A MORE UNFAVORABLE
ENVIRONMENT BENEATH UPPER RIDGE OVR CENTRAL PA. ACROSS EASTERN
PA...MARINE STRATUS DECK...WHICH COVERS AREAS EAST OF THE SUSQ
RIVER AT 0930Z...SHOULD MIX OUT TO SCT-BKN CU BY LATE AM.
AS RIDGE AXIS SLIDES EAST...PLUME OF HIGHER PWATS WILL OVERSPREAD
THE REGION TODAY. THE INCREASED HUMIDITY/INSTABILITY...COMBINED
WITH PASSAGE OF A WEAK MID LVL VORT MAX...SHOULD SUPPORT SCT PM
TSRA...ESP ACROSS THE CENTRAL MTNS. AN EXAMINATION OF MDL
SOUNDINGS SHOWS MODERATE CAPE OF ARND 1500 J/KG AND WEAK
SHEAR...IMPLYING MOSTLY PULSE TYPE CONVECTION W/LITTLE RISK OF
ORGANIZED SVR WX. MDL 8H TEMPS SUPPORT HIGHS IN THE L/M80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
BULK OF MDL DATA SUPPORTS A LULL IN CONVECTIVE ACTIVITY THIS
EVENING BTWN SCT DIURNALLY-DRIVEN ACTIVITY LATE THIS AFTN AND
ARRIVAL OF SHARP COLD FRONT LATE TONIGHT. ALL MDL DATA TRACKS COLD
FRONT THRU MOST OF CENTRAL PA BTWN 06Z-12Z TUESDAY...LIKELY
SPARING THE AREA SVR WX. IN ADDITION...PARENT SHORTWAVE AND BULK
OF LG SCALE FORCING IS PROGGED TO PASS WEST OF PA THRU THE GRT
LKS. HAVE PLACED THE HIGHEST /LKLY/ POPS ACROSS THE NW MTNS
TONIGHT AND THE LOWEST CHC OF RAIN ACROSS THE SE
COUNTIES...FURTHEST FROM UPPER LVL SUPPORT. TONIGHT WILL LIKELY BE
THE WARMEST NIGHT OF OUR RECENT STRING OF WARM NIGHTS...DUE TO
SURGING LOW LVL MOISTURE AND INCREASING CLOUD COVER.
TUESDAY WILL BE A DRY AND WINDY DAY FOR MOST OF CENTRAL PA BEHIND
COLD FRONT...AS STRENGTHENING PARENT LOW PASSES NORTH OF PA.
BUFKIT SOUNDINGS SUPPORT WGUSTS TO ARND 30KTS. AN ADDITIONAL
-SHRA IS POSSIBLE IN A FEW SPOTS TUES AFTN WITH PASSAGE OF UPPER
LVL TROF AXIS. HOWEVER...PTSUNNY AND DRY WX EXPECTED FOR MOST.
ENS MEAN 8H TEMPS STILL INDICATE TEMPS ABOVE NORMAL WITH MAX
READINGS LIKELY RANGING FROM THE U60S OVER THE NW MTNS...TO THE
L80S ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER TROF AND COOL TEMPS ALOFT WILL REMAIN OVR PA
WED...LKLY RESULTING IN A GOOD DEAL OF AFTN CU/STRATOCU...ESP OVR
THE MTNS. 8H TEMPS SUPPORT HIGHS ONLY IN THE 50S TO L60S. THURSDAY
MORNING COULD BE QUITE CHILLY...AS SFC HIGH BUILDS OVER THE AREA.
MAY HAVE TO CONTEND W/POSSIBLE FROST OVR THE NW MTNS THOSE
MORNINGS WITH MINS LKLY IN THE 30S. GROWING SEASON STARTS MAY 11
OVER PARTS OF THE ALLEGHENY MTNS. CONFIDENCE IN NEAR-FREEZING
TEMPS IS HIGHEST IN MCKEAN/POTTER AND ELK BUT THE GROWING SEASON
DOES NOT BEGIN IN THESE COUNTIES UNTIL MAY 21.
BY LATE NEXT WEEK...ALL MED RANGE GUIDANCE SHOWS UPPER LVL RIDGE
REBUILDING ACROSS THE GRT LKS. HAVE INTRODUCED THE CHC OF SHOWERS
LATE FRIDAY/SATURDAY...WHEN MDLS SHOW A SHORTWAVE CRESTING RIDGE
AND DIVING SE TOWARD PA.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
UPPER RIDGE REMAINS OVER THE REGION. WEAK SHORTWAVE SLIDING OVER
LAKE ERIE MAY KICK OFF ISOLATED SHOWERS/TSRA WEST OF KBFD THROUGH
10Z. BUT MAIN FOCUS OVERNIGHT WILL BE THE REDEVELOPMENT OF
STRATUS/FOG DECK OVER SE PORTIONS OF PA. SREF CIG PROBS AND MDL
SOUNDINGS SUGGEST THE LOW CLOUDS COULD REACH ALL THE WAY TO THE
CENTRAL MTNS...THOUGH BEST CHANCES FOR EXTENDED PERIOD OF
REDUCTIONS WILL BE AT KMDT-KLNS - FROM 08Z THROUGH THE MID
MORNING.
WE/LL SEE A BETTER CHANCE FOR SHRA/TSRA DURING THE DAY ON MON AS
RIDGE BEGINS TO BREAKS DOWN /AND REMNANTS OF ANA SLIDE TOWARD THE
MID ATLANTIC COAST/ WHILE LOW-LEVEL MOISTURE CONTINUES TO INCREASE.
SCT TO NUM SHOWERS WILL DEVELOP IN THE AFTERNOON AND CONTINUE INTO
THE EVENING HOURS MAINLY ACROSS THE NW HALF OF CWA...ALONG WITH
ISOLATED LATE DAY TSTMS.
OUTLOOK...
MON...SCT-NUMEROUS AFTERNOON AND EARLY NIGHTTIME TSRA IMPACTS
POSSIBLE. PATCHY MVFR TO IFR IN FOG LATE.
TUE...MORNING LOW CLOUDS AND FOG POSSIBLE...THEN BREEZY AND LESS
HUMID WITH AREAS OF MVFR CIGS ACROSS THE NRN AND WRN MTNS.
WED-THU...VFR.
FRI...MVFR WITH SCT SHRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
659 AM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL TURN NORTHEAST AND MOVE ACROSS EASTERN
TODAY...BEFORE MOVING OFF THE VIRGINIA COAST. A COLD FRONT WILL
CROSS OUR AREA ON TUESDAY. HIGH PRESSURE WILL MOVE FROM THE GREAT
LAKES WEDNESDAY TO OFF THE MID ATLANTIC COAST BY NEXT WEEKEND AS
MOISTURE FLOWS UP FROM THE GULF AND INTO OUR AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 655 AM...EARLIER CONVECTION HAS DISSIPATED. IN FACT...SKIES
ARE CLEAR ACROSS MUCH OF THE FORECAST AREA...EXCEPT FOR SOME AREAS
OF FOG/LOW STRATUS ACROSS THE MTN VALLEYS. THE CLEAR SKIES SHOULD
ALLOW TEMPS TO SOAR INTO THE 70S AND LOWER 80S BY LATE MORNING.
AS OF 310 AM...ISOLATED CONVECTION CONTINUES TO FIRE ALONG A
GRADIENT IN MUCAPE SOUTH OF THE I-85 CORRIDOR THIS MORNING. WILL
CONTINUE TO RETAIN 20 POPS IN THIS AREA THROUGH ABOUT DAYBREAK.
OTHERWISE...ATTENTION TURNS TO THE CONVECTIVE POTENTIAL FOR LATER
TODAY. DEWPOINTS IN THE MID/UPPER 60S ARE EXPECTED TO COMBINE WITH
STEEP LOW LEVEL LAPSE RATES TO YIELD SOME OF THE MORE ROBUST CAPE
VALUES WE/VE SEEN IN RECENT DAYS...WITH A CONSENSUS OF DETERMINISTIC
AND ENSEMBLE GUIDANCE CLEARLY SUPPORTING SBCAPE IN THE 2000-2500
J/KG RANGE THIS AFTERNOON. IN ADDITION...MOISTURE WILL BE MORE
PLENTIFUL THROUGH A DEEP LAYER...WITH PWATS OF AROUND 1.5...OR ABOUT
2 STANDARD DEVS ABOVE CLIMO...EXPECTED ACROSS THE PIEDMONT THIS PM.
WHAT WILL BE LACKING IS AN OBVIOUS SOURCE OF ORGANIZED LIFT.
HOWEVER...IT IS INTERESTING THAT SOME OF THE CONVECTION-ALLOWING
MODELS...AND EVEN THE NAM APPEAR TO BE HIGHLIGHTING A LOW LEVEL
CONVERGENCE AXIS ACROSS EAST TENN AND NORTH GA. THE HRRR AND NSSL
WRF LIGHT THIS AREA UP...SUGGESTING (AT LEAST) NUMEROUS CONVECTIVE
COVERAGE BY EARLY/MID AFTERNOON...WHICH WOULD PUSH INTO OUR AREA
BY MID/LATE AFTERNOON. LIKELY POPS WILL BE CARRIED OVER THE
MTNS...WHERE DIFF HEATING STILL APPEARS TO BE THE BEST BET FOR
INITIATING CONVECTION. HOWEVER...POPS HAVE ALSO BEEN BUMPED TO 50
PERCENT ACROSS MUCH OF THE REMAINDER OF THE WESTERN HALF OF THE
FORECAST AREA. IF THE MESOSCALE MODELS HAVE THE RIGHT IDEA...
THIS WILL BE TOO LOW. WHILE PROFILES ARE GENERALLY MOIST...STEEP
LOW LEVEL LAPSE RATES/A HOT BOUNDARY LAYER SHOULD YIELD
DOWNDRAFT CAPE IN THE 500-1000 J/KG RANGE THIS AFTERNOON...WHICH
COULD COMBINE WITH WEAK SHEAR AND WATER LOADING TO YIELD A WET
MICROBURST THREAT WITH SOME OF THE STRONGER UPDRAFTS. WHILE DEEP
LAYER SHEAR IS WEAK...THERE COULD BE JUST ENOUGH SHEAR OVER COLD
POOL DEPTH TO PROMOTE SOME DEGREE OF LIMITED UPSCALE ORGANIZATION...
WHICH WOULD RESULT IN A MORE ORGANIZED DOWNBURST THREAT.
COVERAGE OF CONVECTION WILL GRADUALLY DIMINISH TONIGHT. A COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY
OVERNIGHT. HOWEVER...THERE IS A DEFINITIVE MODEL CONSENSUS
SUGGESTING THAT ANY ASSOCIATED CONVECTION WILL BE DIMINISHING AS THE
BOUNDARY NUDGES INTO THE FORECAST AREA TOWARD DAYBREAK. TOKEN SMALL
CHANCE POPS WILL NEVERTHELESS BE RETAINED. TEMPERATURES WILL REMAIN
A SOLID 10 DEGREES ABOVE CLIMO THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AT 300 AM EDT MONDAY...ON TUESDAY MORNING NEARLY ZONAL FLOW WILL
EXTEND FROM THE SOUTHERN ROCKIES TO THE MID ATLANTIC COAST...WHILE
AN UPPER TROUGH CROSSES THE GREAT LAKES. ON WEDNESDAY AND UPPER
RIDGE AMPLIFIES OVER THE MS RIVER VALLEY. ON WEDNESDAY NIGHT THIS
RIDGE PROGRESSES TO THE TN AND OH RIVER VALLEYS AND THE GREAT LAKES.
A COLD FRONT WILL CROSS OUR AREA EARLY TUESDAY...ACCOMPANIED BY
PRECIPITATION. INSTABILITY WILL SUPPORT THUNDERSTORMS ALONG AND AHEAD
OF THE FRONT...AND SOME SHEAR WILL BE PRESENT...PERHAPS SUPPORTING
SOME ORGANIZATION TO THE STORMS.
THE FRONT STALLS NEAR THE GULF COAST ON TUESDAY NIGHT...WHILE DRIER
AIR MOVES INTO OUR AREA FROM THE NW. DRY HIGH PRESSURE BUILDS DOWN
THE EAST SLOPES OF THE APPALACHIANS ON WEDNESDAY NIGHT...WHILE THE
STALLED FRONT REMAINS TO OUR S. TEMPERATURES WILL RUN WELL ABOVE
NORMAL IN DOWNSLOPE WARMING BEHIND THE FRONT...COOLING TO SLIGHTLY
ABOVE NORMAL AS COOLING WITH THE POST FRONTAL AIR MASS IS OFFSET BY
RISING HEIGHTS ALOFT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 300 AM EDT MONDAY...ON THURSDAY MORNING AND UPPER RIDGE WILL BE
CENTERED OVER SW FL...EXTENDING N TO THE GREAT LAKES...WHILE TROUGHS
WILL BE OFF THE WEST AND EAST COASTS. A WELL DEFINED SHORTWAVE WILL
BE MOVING ACROSS THE PLAIN AT THAT TIME. BY FRIDAY MORNING THE
SHORTWAVE CROSSES THE UPPER MS RIVER VALLEY...AND BY SATURDAY
MORNING IT WEAKENS OVER THE NORTHEAST. MEANWHILE...THE UPPER RIDGE
REMAINS FROM THE GULF TO THE GREAT LAKES...WHILE A CLOSED LOW MOVES
INLAND FROM THE CA COAST TO UT. BY SUNDAY THE RIDGE AXIS PROGRESSES
TO THE APPALACHIANS...WHILE THE UPPER LOW MOVES INTO WY...AND
ANOTHER UPPER LOW APPROACHES THE CA COAST.
AT THE SURFACE...HIGH PRESSURE WILL EXTEND FROM THE GREAT LAKES TO
THE EAST COAST AND GULF STATES THURSDAY MORNING...WHILE A STATIONARY
FRONT EXTENDS FROM N FL TO THE GULF COAST. ON FRIDAY THE SURFACE
RIDGE WILL BE OVER THE EASTERN SEABOARD...WHILE GULF INFLOW SETS UP
TO THE WEST. ISENTROPIC UPGLIDE OVER THE SURFACE RIDGE WILL SUPPORT
PRECIPITATION OVER OUR AREA...BUT INSTABILITY APPEARS TO BE LACKING
AT THIS TIME.
THE SURFACE RIDGE MOVES OFF THE EAST COAST ON SATURDAY...ALLOWING
GULF INFLOW TO SPREAD EAST TOWARD THE SOUTHERN APPALACHIANS....AND
THIS PATTERN PERSISTS INTO SUNDAY. INCREASING INSTABILITY WILL
SUPPORT A RETURN OF THUNDERSTORMS...BUT AT THIS POINT SHEAR APPEARS
TO BE QUITE LIMITED...AND ORGANIZED CONVECTION UNLIKELY.
TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL RANGE DUE TO CLOUD COVER
AND INCREASING MOISTURE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE (EXCEPT MTN VALLEYS)...VFR CONDITIONS ARE
GENERALLY EXPECTED UNTIL AFTERNOON...ALTHOUGH BRIEF MVFR VISBY WILL
BE POSSIBLE EARLY THIS MORNING...ESP AT KAND/KHKY. WINDS WILL BECOME
SW AT 7-10 KTS AT MOST TERMINALS THIS AFTERNOON...WITH GUSTS IN THE
TEENS POSSIBLE. THE PRIMARY CONCERN FOR THE FORECAST PERIOD WILL BE
THE POTENTIAL FOR DEEP CONVECTION LATER TODAY...WHICH SHOULD BE
QUITE A BIT HIGHER THAN IN RECENT DAYS. THIS IS DUE TO IMPROVING
MOISTURE AND INSTABILITY PROFILES. THERE IS STILL SOME QUESTION AS
TO HOW EXTENSIVE COVERAGE WILL BE...BUT CURRENT INDICATIONS ARE THAT
COVERAGE WILL BE GREATEST ACROSS UPSTATE SC AND THE NC MTNS.
NEVERTHELESS...PROB30S ARE CERTAINLY WARRANTED AT ALL TERMINALS FROM
MID-AFTERNOON ON. TEMPOS WILL LIKELY NEED TO BE ADDED TO SOME OR ALL
OF THE TERMINALS AT SOME POINT...BUT TIMING IS TOO UNCERTAIN TO
INCLUDE ATTM.
AT KAVL/MTN VALLEYS...LIFR/BRIEF VLIFR CONDITIONS WILL PERSIST IN
THE MTN VALLEYS UNTIL 14Z OR SO. OTHERWISE...CONVECTION IS EXPECTED
TO DEVELOP OVER THE HIGH TERRAIN SURROUNDING THE MTN TERMINALS BY
EARLY AFTERNOON...AND A CATEGORICAL MENTION OF SHRA/VCTS STILL
APPEARS WARRANTED BY MID-AFTERNOON. COVERAGE OF CONVECTION WILL
DIMINISH THIS EVENING...BUT AT LEAST ISOLATED SHOWERS SHOULD LINGER
INTO THE OVERNIGHT. ANOTHER ROUND OF FOG/STRATUS IS POSSIBLE LATE
TONIGHT...BUT CONDITIONS ARE TOO UNCERTAIN TO FORECAST RESTRICTIONS
ATTM.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...BRINGING
ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE IN ON
WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE SOUTH...POSSIBLY
ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA LATE IN THE WEEK.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 62% 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.
&&
$$
SYNOPSIS...JAT
NEAR TERM...JDL
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1030 AM CDT MON MAY 11 2015
.UPDATE...
MAIN ITEM OF INTEREST FOR THE TODAY PERIOD IS THE CHANCES FOR A
COUPLE STRONG TO POSSIBLY SEVERE STORMS. SPC HAS OUR SW COUNTIES
HIGHLIGHTED WITH A SLIGHT RISK AND THE REST OF THE AREA WITH A
MARGINAL RISK. HRRR INDICATES 1000-1500 J/KG SBCAPE SNEAKING INTO
THE SOUTHWEST BY 18Z WITH SOME STORMS APPROACHING THAT AREA AT THE
TIME. CURRENTLY RADAR SHOWS SOME STORMS IN THE NORTH CENTRAL MS.
TIMING THESE STORMS OUT PUTS THEM INTO OUR WESTERN COUNTIES AROUND
19Z. LATEST RUN OF THE HRRR IS MORE BULLISH WITH THE AMOUNT OF
PRECIPITATION BROUGHT INTO THE AREA. PREVIOUS RUNS WERE MORE
SCATTERED IN NATURE. TEND TO AGREE WITH THE EARLIER RUNS GIVEN THE
LACK OF CONVERGENCE AND SUPPORT FOR THE STORMS. WITH ALL OF
THIS...KEPT POPS AS THEY WERE.
OVERALL HIGH TEMPERATURES ARE ON PACE. TWEAKED SOME HOURLY TEMPS
ESPECIALLY TO THE EAST WHERE FULL SUN HAS ALLOWED A QUICK WARM UP
BUT WARMING TRENDS SHOULD BE TEMPERED AS CLOUDS MOVE IN FROM THE
WEST.
REAGAN
&&
.PREV DISCUSSION... /ISSUED 628 AM CDT MON MAY 11 2015/
UPDATE...FOR AVIATION.
AVIATION...
12Z TAFS...SCATTERED TSRA WILL DEVELOP OVER THE AREA TODAY AHEAD
OF A COLD FRONT. SOME SEVERE STORMS ARE POSSIBLE. OUTSIDE ANY
TSRA...VFR EXPECTED WITH GUSTY SSW WINDS TO 22KT AT TIMES. TSRA
CHANCES WILL DECREASE TONIGHT. WINDS WILL DIMINISH AND VEER TO
THE NW OVERNIGHT.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
953 AM CDT MON MAY 11 2015
.UPDATE...
A BAND OF RAIN SHOWERS IS WEAKENING WHILE MOVING IN FROM THE WEST
WITH DEVELOPING SHOWERS AND THUNDERSTORMS SOUTH OF MEMPHIS ALONG
THE INTERSTATE 55 CORRIDOR. THE ATMOSPHERE IS PRETTY WELL WORKED
OVER ALONG AND WEST OF THE MISSISSIPPI RIVER...SO ANY ADDITIONAL
STRONG OR SEVERE STORMS WOULD DEVELOP IN EASTERN PORTIONS OF WEST
TENNESSEE AND IN NORTH MISSISSIPPI EAST ON INTERSTATE 55. CURRENT
THINKING IS THAT THE LINE IN NORTH MISSISSIPPI ALONG INTERSTATE 55
WILL CONTINUE TO STRENGTHEN AS IT SHIFTS EAST AND MAY BUILD
SLIGHTLY FARTHER NORTH INTO WEST TENNESSEE...BUT WILL MOST LIKELY
REMAIN BELOW SEVERE LIMITS AS EXTENSIVE CLOUD COVER OVER THE
REGION CURBS INSTABILITY. UPPER LEVEL SUPPORT FOR SEVERE STORMS
SHOULD CONTINUE TO DIMINISH WITH TIME.
&&
.PREV DISCUSSION... /ISSUED 618 AM CDT MON MAY 11 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 11 2015/
DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...12Z TAFS
LINE OF TSTMS WILL ADVANCE THROUGH THE TAF SITES EARLY...WITH TUP
BEING LEAST AFFECTED. EXPECT IFR/MVFR CONDITIONS WITHIN THE
HEAVIEST ACTIVITY AND VARIABLE WIND GUSTS. OUTSIDE OF STORMS
WEATHER WILL BE VFR WITH SOUTHWEST WINDS INCREASING TO 10-12 KTS
AND BECOMING GUSTY BY LATE MORNING. COLD FRONT WILL PUSH THROUGH
THIS AFTERNOON/EVENING...WITH A GRADUAL DECREASE IN CLOUD COVER
AND SUBSIDING WINDS.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
618 AM CDT MON MAY 11 2015
.DISCUSSION...
UPDATED FOR 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 11 2015/
DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...
12Z TAFS
LINE OF TSTMS WILL ADVANCE THROUGH THE TAF SITES EARLY...WITH TUP
BEING LEAST AFFECTED. EXPECT IFR/MVFR CONDITIONS WITHIN THE
HEAVIEST ACTIVITY AND VARIABLE WIND GUSTS. OUTSIDE OF STORMS
WEATHER WILL BE VFR WITH SOUTHWEST WINDS INCREASING TO 10-12 KTS
AND BECOMING GUSTY BY LATE MORNING. COLD FRONT WILL PUSH THROUGH
THIS AFTERNOON/EVENING...WITH A GRADUAL DECREASE IN CLOUD COVER
AND SUBSIDING WINDS.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR CLAY-
CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...FLASH FLOOD WATCH UNTIL 1 PM CDT THIS AFTERNOON FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
947 AM CDT MON MAY 11 2015
.DISCUSSION...GFE FORECAST MONITOR SHOWING THINGS ARE FINE WITH
RESPECT TO TEMPS/WINDS AND CLOUDS. CONCERNING RAIN CHANCES...SOME
SPOTTY SHOWERS STARTING TO SHOW UP MAINLY OVER THE NORTHERN AREAS
WHERE SURFACE CONVERGENCE IS LOCATED AND CAP IS ERODING FAST.
OVERALL...FORECAST LOOKS GOOD. BASED ON 4 KM MODELS AND
APPROACHING CONVECTION SEEPING SLOWLY SOUTHWARD...WILL MENTION
SEVERE FOR THIS AFTERNOON OVER THE WESTERN AREAS (AND MAY INCLUDE
REMAINDER OF NORTHERN AREAS IF DIFFERENT TRENDS DEVELOP)...BUT
THINK MAIN CONCERN WILL BE WESTERN AREAS. ALSO WILL MENTION HEAVY
RAINFALL OVER THE NORTHERN AREAS THIS AFTERNOON AND ALL AREAS
TONIGHT. CONCERNING RIP CURRENT RISK...IT IS STARTING TO GO DOWN
BUT IT WAS CLOSE THIS MORNING. BASED ON OBSERVATIONS FROM
BOY020...SWELLS HAVE FALLEN TO 4 FEET OR LESS (AND TREND IS
FALLING)...WITH PERIODS STILL 7 TO 8 FEET. MODERATE WILL DO.
TIDES ARE STILL WELL BELOW 2 FEET...WITH MOST BELOW 1.5 FEET AND
HEIGHTS OF HIGH TIDES ARE SLIGHTLY LOWER. MARINE FORECAST IS OK.
MINOR UPDATES OF PRODUCTS WILL BE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 636 AM CDT MON MAY 11 2015/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...LOW END VFR AND MVFR CEILINGS CAN BE EXPECTED THROUGH
MUCH OF THE PERIOD. CHANCES FOR SHOWERS AND STORMS WILL INCREASE
AS SLOW MOVING COLD FRONT APPROACHES SOUTH TEXAS. LATEST HRRR HAS
SLOWED DOWN ONSET OF CONVECTION SO WILL KEEP VCTS REMARKS FOR
NOW. IF THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS...HEAVY
RAIN...BRIEF GUSTY WINDS AND REDUCED VSBYS WILL BE LIKELY. WINDS
THROUGH THE PERIOD WILL BE PREDOMINANTLY OUT OF THE E AND ESE WITH
SPEEDS LESS THAN 15 KNOTS.
PREV DISCUSSION... /ISSUED 427 AM CDT MON MAY 11 2015/
SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
636 AM CDT MON MAY 11 2015
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...LOW END VFR AND MVFR CEILINGS CAN BE EXPECTED THROUGH
MUCH OF THE PERIOD. CHANCES FOR SHOWERS AND STORMS WILL INCREASE
AS SLOW MOVING COLD FRONT APPROACHES SOUTH TEXAS. LATEST HRRR HAS
SLOWED DOWN ONSET OF CONVECTION SO WILL KEEP VCTS REMARKS FOR
NOW. IF THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS...HEAVY
RAIN...BRIEF GUSTY WINDS AND REDUCED VSBYS WILL BE LIKELY. WINDS
THROUGH THE PERIOD WILL BE PREDOMINANTLY OUT OF THE E AND ESE WITH
SPEEDS LESS THAN 15 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 427 AM CDT MON MAY 11 2015/
SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
737 AM EDT MON MAY 11 2015
.SYNOPSIS...
LOW PRESSURE WAS OVER SOUTH DAKOTA WITH A COLD FRONT TRAILING INTO
NORTHERN TEXAS. THIS FRONT WILL MOVE EAST TODAY AND TONIGHT AND
WILL BE OFF THE COAST BY TUESDAY NIGHT. TROPICAL DEPRESSION ANA
WAS OVER EASTERN NORTH CAROLINA AND WILL WEAKEN AND MOVE
NORTHEAST TO THE MASSACHUSETTS COAST BY TUESDAY MORNING.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 415 AM EDT MONDAY...
WATCHING TWO FEATURES THIS MORNING. TROPICAL DEPRESSION ANA WAS IN
EAST CENTRAL NORTH CAROLINA AND WILL ACCELERATE AND OPEN IN A TROF
BY LATE TONIGHT. A SHORT WAVE ON THE NORTHERN EDGE OF THE SOUTHEAST
UPPER RIDGE WAS MOVING THROUGH THE OHIO VALLEY AND WAS GENERATING
SHOWERS AND ISOLATED THUNDERSTORMS OVER WEST VIRGINIA.
LOCAL WRF MODELS SHOWED A NORTH-SOUTH ORIENTED AXIS OF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS MOVING INTO THE WESTERN COUNTY
WARNING AREA BEFORE 8AM...THEN WEAKENING LATE THIS MORNING. HAVE
ALIGNED PROBABILITY OF PRECIPITATION THROUGH NOON WITH CURRENT RADAR
TRENDS AND THE LOCAL WRF.
OUTFLOW BOUNDARY CROSSING THROUGH OHIO AND KENTUCKY MAY BECOME THE
FOCUS FOR SHOWERS AND THUNDERSTORMS FARTHER EAST THIS AFTERNOON.
APPEARS BEST WINDOW FOR PRECIPITATION WILL BE WITH THE OUTFLOW OR
PRE-FRONTAL TROF...MAINLY BETWEEN 18Z/2PM AND 03Z/11PM. SOME MODELS
WERE CONFINING SHOWERS AND THUNDERSTORMS TO JUST THE WESTERN COUNTY
WARNING AREA...BUT DON`T SEE WHY THE CHANCE WOULD NOT EXTENDED INTO
THE EASTERN PART OF THE FORECAST AREA ONCE THE WINDS COME AROUND TO
THE SOUTHWEST.
ACTUAL COLD FRONT CROSSES THROUGH THE FORECAST AREA LATE TONIGHT.
HAVE KEPT IN UPSLOPE SHOWERS BEHIND THE FRONT INTO TUESDAY MORNING
FOR SOUTHEAST WEST VIRGINIA.
NO CHANGE IN AIR MASS TODAY OR TONIGHT AHEAD OF THE FRONT. MAXIMUM
TEMPERATURES TODAY WILL STILL BE ABOVE NORMAL WITH ANY DECENT AMOUNT
OF SUN.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM EDT MONDAY...
BY TUESDAY MORNING...THE REMNANTS OF ANA WILL BE LOCATED OFF THE NEW
JERSEY SHORE AND TRAVEL NORTHEAST TO OFF THE NEW ENGLAND COAST BY
TUESDAY AFTERNOON INTO TUESDAY NIGHT.
THE UPPER LOW WILL CONTINUE TO SHEAR OUT TUESDAY AND SHIFT INTO THE
EASTERN GREAT LAKES/SOUTHEASTERN CANADA. AT THE SURFACE...A COLD
FRONT ATTENDANT TO UPPER TROUGH WILL ADVANCE SOUTHEAST ACROSS THE
REGION...THEN MOVE OFF THE ATLANTIC COAST TUESDAY EVENING/NIGHT.
THE PROXIMITY OF THE BOUNDARY...GOOD THERMODYNAMICS AND
HEATING...SUPPORT THE MENTION OF SCATTERED AFTERNOON SHOWERS AND
THUNDERSTORMS ACROSS THE PIEDMONTS NEAR AND SOUTH OF THE FRONT. THE
DAY TWO CONVECTIVE OUTLOOK HAS PLACE A MARGINAL (5 PERCENT) TO
THE SOUTHEAST OF OUR AREA ACROSS EASTERN NORTH CAROLINA AND
SOUTHEAST VIRGINIA. HIGH TEMPERATURES TUESDAY WILL REMAIN ABOVE
NORMAL WITH READINGS FROM THE MID 60S IN THE NORTHWEST MOUNTAINS
TO THE UPPER 80S IN THE PIEDMONTS. DRIER AIR FROM THE OHIO VALLEY
PUSHES SOUTH ACROSS OUR AREA TUESDAY NIGHT. LOW TEMPERATURES WILL
SEEM CHILLY COMPARED TO RECENT DAYS WITH VALUES FROM LOWER 40S IN
THE NORTHERN MOUNTAINS TO THE MID 50S IN THE SOUTHEAST.
HIGH PRESSURE CONTINUES TO SLIDE EASTWARD WEDNESDAY INTO WEDNESDAY
NIGHT. DRY AIR WILL FILTER INTO THE REGION AT LEAST FOR A COUPLE OF
DAYS...ALLOWING DEWPOINTS TO DROP INTO THE 30S AND 40S ACROSS THE
MOUNTAINS AND 50S ELSEWHERE. HIGH TEMPERATURES WEDNESDAY WILL RANGE
THE UPPER 50S IN THE NORTHWEST MOUNTAINS TO THE UPPER 70S IN THE
PIEDMONTS. UNDER A BUILDING UPPER RIDGE...WEDNESDAY NIGHT LOW
TEMPERATURES WILL DROP INTO THE LOWER 40S IN THE WEST TO LOWER 50S
IN THE EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 400 PM EDT SUNDAY...
THURSDAY SHOULD BE ONE FINAL DRY DAY ACROSS THE REGION WITH RELATIVE
LOW HUMIDITIES AND NEAR NORMAL MAX TEMPS AND NEAR TO SLIGHTLY BELOW
NORMAL MIN TEMPS... 60S AND 70S MOUNTAINS MOUNTAINS TO NEAR 80
PIEDMONT...WITH LOWS IN THE 40S MOUNTAINS AND 50S ELSEWHERE.
FOR FRI AND INTO THE WEEKEND...THE REGION SHIFTS INTO A LARGELY
SUMMERLIKE PATTERN WITH INCREASINGLY OPPRESSIVE LEVELS OF HUMIDITY
AS A SUBTROPICAL RIDGE BUILDS ACROSS THE SOUTHEAST STATES. A
POTENTIALLY SIGNIFICANT OVERRUNNING EVENT WILL PRECEDED THE
TRANSITION FROM THE DRIER CONDITIONS OF THU TO THE SUMMERLIKE
PATTERN EXPECTED BY THE WEEKEND AS THE RETURNING FRONTAL BOUNDARY
COMBINES WITH AN UPPER LEVEL SHORT WAVE AND THE RETURN OF DEEP
GULF MOISTURE. WIDESPREAD RAIN AND A FEW THUNDERSTORMS APPEAR
LIKELY FRIDAY...ESPECIALLY IN THE WEST.
THEREAFTER...ACTIVITY WILL BECOME INCREASINGLY DIURNALLY FOCUSED
WITH AN UPPER RIDGE DEVELOPING OVER THE REGION AS YET ANOTHER
TROUGH FILLS INTO THE SOUTHWEST U.S. HIGH TEMPERATURES IN THE 70S
WEST AND THE 80S EAST WILL RULE THROUGH MUCH OF THE PERIOD WITH
INCREASING HUMIDITY LEVELS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 735 AM EDT MONDAY...
FIRST VISIBLE SATELLITE PICTURES THIS MORNING SHOWED PATCHY IFR
TO LIFR SHALLOW FOG IN THE WESTERN VALLEYS. EXPECT KLWB AND KBCB
TO RETURN TO VFR BY 14Z/10AM.
A COLD FRONT WILL CROSS THROUGH THE AREA LATE THIS AFTERNOON INTO
THIS EVENING. AHEAD OF THIS FRONT SHORT RANGE WRF AND HRRR PAST
FEW RUNS HAVE SHOWN SHOWER AND THUNDERSTORM DEVELOPMENT BEGINNING
AROUND 17Z/1PM IN THE MOUNTAINS. LOW LEVEL MOISTURE AND WEST WINDS
WILL BRING MVFR CEILINGS TO KBLF AND KLWB OVERNIGHT. LOW CONFIDENCE
IF CEILINGS WILL BE LOWER THAN MVFR.
A MUCH DRIER AIR MASS COMES INTO THE REGION WITH VFR CONDITIONS
TUESDAY THROUGH THURSDAY. GUSTY NORTHWEST WINDS ARE EXPECTED ON
TUESDAY AND POSSIBLY WEDNESDAY. THE NEXT CHANCE OF SUB VFR WEATHER
AND PRECIPITATION WILL BE ON FRIDAY.
&&
.CLIMATE...
AS OF 425 AM EDT MONDAY...
A FEW MAXIMUM TEMPERATURE RECORDS MAY BE SET TODAY.
HERE ARE THE CURRENT RECORD HIGHS...
ROANOKE 91 IN 1953
LYNCHBURG 94 IN 1896
DANVILLE 94 IN 1953
BLUEFIELD 83 IN 2007
LEWISBURG 82 IN 2007
BLACKSBURG 84 IN 2007
RECORD WARM MINIMUM TEMPERATURES ARE ALSO POSSIBLE.
ROANOKE 64 IN 1991
DANVILLE 68 IN 1963
BLUEFIELD 62 IN 2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS/NF
CLIMATE...AMS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1118 AM MDT MON MAY 11 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
DRIER DAY IN STORE FOR THE FORECAST AREA WITH TEMPS REBOUNDING
AFTER A COUPLE OF COOLER DAYS. HRRR AND NAM12 GENERATING A FEW
LATE DAY SHOWERS OVER THE HIGHER PEAKS...OTHERWISE IT WILL BE A
DRY DAY ACROSS THE REGION. QUIET PATTERN CONTINUES TONIGHT WITH
SHORTWAVE RIDGING SLIDING EAST INTO THE PLAINS. THIS ALLOWS FOR A
QUICK RETURN TO SOUTHERLY FLOW WITH ANOTHER SURGE OF MOISTURE
WORKING NORTHWARD BY MIDDAY TUESDAY. PRECIPITABLE WATER VALUES
CLIMB TO OVER A HALF INCH ACROSS THE SOUTHERN MOUNTAINS BY LATE
TUESDAY AFTERNOON...SO POTENTIAL FOR LOCALLY HEAVY RAIN IS NOT OUT
OF THE QUESTION. MODELS ARE IN GOOD AGREEMENT WITH AT LEAST
SCATTERED CONVECTION FIRING OVER THE MOUNTAINS AND SOUTHERN
VALLEYS TUESDAY AFTERNOON AND EVENING AND HAVE RAMPED POPS UPWARD.
TEMPS WILL BE MARCHING TOWARD ABOVE NORMAL READINGS BY TUESDAY
AFTERNOON IN THE STRENGTHENING SOUTHERLY FLOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 425 AM MDT MON MAY 11 2015
SHOWERS LINGER TUESDAY EVENING BEFORE A PACIFIC NW WAVE SHUNTS
THE NORTHERLY PROGRESSING MOISTURE BACK TO OUR EAST...WITH GENERAL
DECREASE IN ACTIVITY THROUGH MIDDAY WEDNESDAY. DIURNAL HEATING AND
LINGERING LOW LEVEL MOISTURE SHOULD FIRE A FEW MORE SHOWERS AND
THUNDERSTORMS WEDNESDAY AFTERNOON AND AGAIN THURSDAY. ACTIVITY
PICKS UP IN EARNEST BY FRIDAY AS ANOTHER STRONG LOW PUSHES INTO
THE GREAT BASIN. DEEP SWLY FLOW TAPS MOISTURE OFF THE BAJA AND
LIFTS IT NORTHEAST INTO THE FOUR CORNERS EARLY FRIDAY...SPREADING
NORTH IN INCREASINGLY DIFLUENT PATTERN OVER THE FORECAST AREA.
THIS WILL TRIGGER FAIRLY WIDESPREAD SHOWERS AND THUNDERSTORMS BY
FRIDAY AFTERNOON WITH ACTIVITY LIKELY TO CONTINUE THROUGH THE
WEEKEND AS THE LOW LIFTS NORTHEAST INTO WYOMING. LATEST RUNS ARE A
TAD BIT SLOWER AND DEEPER WITH THE LOW VERSUS EARLIER RUNS...BUT
CONFIDENCE IS FAIRLY HIGH WE WILL BE IN FOR ANOTHER WET END OF THE
WEEK. TEMPS WILL BE RUNNING ON THE PLUS SIDE OF NORMAL THROUGH
THURSDAY...WITH GRADUAL COOLING AS WE MOVE INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1115 AM MDT MON MAY 11 2015
NO FLIGHT CONCERNS FOR THE NEXT 24 HOURS OVER TAF SITES. SOME LOW
CLOUDS WILL PERSIST OVER NORTHERN VALLEYS BUT SHOULD LIFT AS THE
DAY PROGRESSES.
&&
.HYDROLOGY...
ISSUED AT 425 AM MDT MON MAY 11 2015
MOST RIVERS IN WESTERN COLORADO REMAIN WELL BELOW BANKFULL STAGES.
HOWEVER...A COMBINATION OF RECENT RAIN FALL AND MELTING MOUNTAIN
SNOW WILL BRING GRADUAL RISES OVER THE NEXT WEEK. A FEW SMALLER
STREAMS AND CREEKS WILL BE RUNNING NEAR BANKFULL.
THE UPPER YAMPA RIVER IS ALREADY AT BANKFULL AND WILL REMAIN NEAR
OR SLIGHTLY ABOVE BANKFULL THROUGH MUCH OF THIS WEEK.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JDC
LONG TERM...JDC
AVIATION...TGR
HYDROLOGY...JDC/AS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
203 PM EDT MON MAY 11 2015
.SYNOPSIS...
HIGH PRESSURE WELL OFFSHORE DRIFTS EAST THROUGH TONIGHT AS LOW
PRESSURE PASSES TO THE SOUTH AND EAST LATE TONIGHT. A COLD FRONT
APPROACHES TUESDAY...PASSING EAST TUESDAY NIGHT...FOLLOWED BY HIGH
PRESSURE. A WEAK LOW PRESSURE SYSTEM MAY AFFECT THE REGION OVER
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOUTHWESTERLY FLOW AROUND HIGH PRESSURE WELL TO THE EAST HAS
MARITIME TROPICAL AIR ADVECTING ACROSS SEAS SURFACE TEMPS IN THE
LOWER 50S. THUS FOG AND STRATUS PERSIST FOR THE SOUTH SHORE OF
LONG ISLAND. DENSE FOG SOUTH OF MONTAUK HIGHWAY AND ESPECIALLY FOR
OCEAN PARKWAY - SPECIAL WEATHER STATEMENT REMAINS EFFECT. AM
PLANNING ON A DENSE FOG ADVISORY ISSUANCE AT 3:30 PM FOR TONIGHT.
OTHERWISE...BACKDOOR COLD FRONT OVER NORTH EASTERN MA AND REMNANTS
OF ANA NEARING NORFOLK. FRONT HAS STRONG 20-25 KT PUSH BEHIND IT
AND MAY REACH NORTHEASTERN SECTION OF THE FORECAST AREA BEFORE
STALLING OUT.
SHOWERS...FORCED BY SURFACE HEATING OVER MONMOUTH AND OCEAN
COUNTY HEADING NNE AT 25 MPH. EXPECT THESE TO DISSIPATE BEFORE
REACHING SOUTHER QUEENS/BROOKLYN.
COULD STILL SEE A SHOWER...PERHAPS A THUNDERSTORM NORTH AND WEST
OF NYC WHERE WEAK INSTABILITY REMAINS. LI`S GET DOWN TO -2 C AND
A FEW HUNDRED JOULES OF CAPE ARE PRESENT. HAVE LEFT THIS OUT OF
THE FORECAST THOUGH AS RAP AND HRRR HAVE NO GOOD SIGNAL ACTIVITY
AND NARRE-TL HAS VERY LOW PROBABILITIES.
TEMPS WERE ADJUSTED SLIGHTLY...MAINLY IN COASTAL SECTIONS FOR
TRENDS WITH THE ONSHORE FLOW. TEMPERATURES SHOULD BE SIMILAR TO
SUNDAY`S HIGHS. LEANED TOWARD THE MUCH WARMER MAV GUIDANCE AND
RAISED A DEGREE OR SO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE SHORTWAVE ASSOCIATED WITH THE REMNANT LOW OF ANA PASSES TO THE
SOUTH AND EAST FROM 06Z TO 12Z AND MAY BRING SOME SHOWERS AND
ISOLATED THUNDER MAINLY TO THE WATERS SOUTH OF LONG ISLAND...WITH
A CHANCE ACROSS EASTERN LONG ISLAND.
MEANWHILE THE UPPER TROUGH AND COLD FRONT SLOWLY APPROACH TONIGHT.
PRECIPITATION STAYS WEST OF THE AREA UNTIL EARLY TUESDAY MORNING
WHEN THE CHANCE OF SHOWERS INCREASES. FORCING WITH THE FRONT WILL
BE MINIMAL ALONG WITH 400 TO 500 CAPE AND WEAK INSTABILITY. SO
WILL KEEP POPS MINIMAL AT SLIGHT CHANCE TO LOW CHANCE. AGAIN
LEANED TOWARD THE WARMER MAV GUIDANCE FOR LOWS AND HIGHS.
DENSE FOG LIKELY RETURNS TO LONG ISLAND AND COASTAL CT THIS
EVENING...THOUGH WSW FLOW TOWARDS MORNING SHOULD CLEAR THINGS UP
QUICKLY ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN GENERAL AGREEMENT WITH MEAN NE TROUGHING THROUGH THE
MIDWEEK...GRADUALLY SLIDING OFFSHORE WITH MORE ZONAL UPPER FLOW FOR
LATE WEEK/WEEKEND.
SHORTWAVE ENERGY PIVOTS INTO THE NORTHEAST TUESDAY NIGHT...WITH
SURFACE COLD FRONT MOVING THROUGH TUESDAY EVENING...PUSHING ANY
LINGERING SHRA/TSRA ACTIVITY OFFSHORE.
SHORTWAVE CONTINUES TO DIG THROUGH THE NE ON WEDNESDAY WITH
SECONDARY COLD FRONT SLIDING THROUGH. ASSOCIATED SCT-BKN AFT
INSTABILITY CU LIKELY...WITH AN ISOLATED INSTABILITY SHRA POSSIBLE
TO DRIFT SE OFF THE HIGHER TERRAIN INTO AREAS WELL N&W OF NYC. MOST
NOTICEABLE WILL BE A CHANGE TO A MUCH DRIER AND COOLER AIRMASS IN
THE WAKE OF THE COLD FRONTS...WITH HIGHS ONLY IN THE 60S FOR MOST OF
THE REGION ACCOMPANIED BY A BREEZY NW WIND. WITH THE TUE FRONTAL
SYSTEM NOT LOOKING LIKE A WETTING RAIN PRODUCER...THE GUSTY AND DRY
COND ON WED MAY LEND TO POTENTIAL FIRE WEATHER CONCERNS.
CHILLY CONDITIONS WED NIGHT AS HIGH BUILDS IN FROM WEST. PATCHY
FROST POSSIBLE ACROSS INTERIOR LOWER HUD AND SOUTHERN CT AS WELL AS
PINE BARRENS OF LI IF WINDS DECOUPLE QUICK ENOUGH.
DRY...TRANQUIL...AND GRADUAL MODERATING TREND TO SEASONABLE TEMPS
THU INTO FRI AS HIGH PRESSURE BUILDS IN FROM THE WEST.
MODELS IN GENERAL AGREEMENT WITH SW US SHORTWAVE ENERGY EJECTING
INTO THE CENTRAL PLAINS LATE WEEK...AND THEN ROUNDING SOUTHERN
RIDGING BUT WEAKENING AS IT APPROACHES THE REGION FRI NIGHT/SAT. AT
THE SURFACE...POTENTIAL EXISTS FOR A RESULTANT WEAK SURFACE LOW TO
TRACK ACROSS THE REGION ON SAT. HAVE INCREASED POPS TO LOW CHANCE
FOR FRIDAY NIGHT AND SAT BASED ON INCREASED MODEL AGREEMENT ON THIS
SCENARIO.
EARLY INDICATIONS ARE FOR DRY AND NEAR SEASONABLE TEMPS ON SUNDAY AS
CANADIAN MARITIMES HIGH BUILDS INTO THE REGION FROM THE NE DUE TO AN
AMPLIFYING TROUGH OFF SE CANADA COAST.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE DRIFTS FURTHER OFFSHORE THROUGH TONIGHT AS LOW
PRESSURE PASSES SOUTH AND EAST OF THE TERMIMALS.
VFR TO START THE TAF PERIOD. CONDITIONS WILL BEGIN TO DETERIORATE
THIS EVENING AND OVERNIGHT TO IFR AND LIFR IN STRATUS AND FOG.
STRATUS AND FOG WILL FIRST RETURN TO KJFK AND KISP AND THEN
OVERSPREAD ALL OTHER TERMINALS THROUGH MIDNIGHT. CONDITIONS
SHOULD BEGIN TO IMPROVE BEFORE SUNRISE ON TUESDAY.
S WINDS 10-15 KT THIS AFTERNOON. GUSTS UP TO AROUND 20 KT FOR
SOME TERMINALS THIS AFTERNOON. S WINDS DIMINISH TONIGHT AND THEN
VEER TO THE SW LATE TONIGHT. SW WINDS INCREASE 10 TO 15 KT WITH
GUSTS 20 TO 25 KT TUESDAY MORNING.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 18-19Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER THAN
CURRENTLY FORECAST.
KLGA FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 19-20Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER/SLOWER THAN
CURRENTLY FORECAST.
KEWR FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 19-20Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER/SLOWER THAN
CURRENTLY FORECAST.
KTEB FCSTER COMMENTS: BRIEF ISO SHOWER POSSIBLE 19-20Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER/SLOWER THAN
CURRENTLY FORECAST.
KHPN FCSTER COMMENTS: IFR/LIFR CONDS THIS EVE COULD COME IN AN
HOUR OR TWO QUICKER THAN CURRENTLY FORECAST.
KISP FCSTER COMMENTS: BRIEF PERIOD OF IFR 18Z TO 19Z. IFR/LIFR
CONDS THIS EVE COULD COME IN AN HOUR OR TWO QUICKER THAN
CURRENTLY FORECAST.
.OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY...
.TUE AFTN...VFR. ISO TSTM. SW GUSTS 25KT.
.WEDNESDAY-FRIDAY...VFR. NW GUSTS 25-30KT WED.
.SATURDAY...MAINLY VFR. MVFR POSS IN SHOWERS.
&&
.MARINE...
DENSE FOG PERSISTS FOR THE WATERS SOUTH OF LONG ISLAND AS WARM
HUMID AIR MOVES OVER THE COLD SEA SURFACE. PATCHES OF CLEARING ARE
EXPECTED...BUT OVERALL...THE DENSE FOG REMAINS SIGNIFICANT AND THE
ADVISORY CONTINUES THROUGH TUESDAY MORNING.
OTHERWISE...SOUTHWESTERLY FLOW WILL PERSIST ACROSS THE FORECAST
WATERS TODAY AND TONIGHT AS HIGH PRESSURE OVER THE NORTHERN
ATLANTIC DRIFTS EAST. SEAS WILL BUILD TO SMALL CRAFT LEVELS
TONIGHT AS SWELLS FROM THE REMNANT LOW OF ANA PASSES TO THE SOUTH
AND EAST. IN ADDITION SOME GUSTS MAY APPROACH 25 KT. SMALL CRAFT
SEAS WILL REMAIN INTO TUESDAY ALONG WITH SOME GUSTY WIND TO NEAR
25 KT AS A COLD FRONT APPROACHES.
SCA CONDITIONS LIKELY ON THE OCEAN WATERS TUESDAY NIGHT FROM
RESIDUALS SCA SOUTHERLY SWELLS AND INCREASING OFFSHORE WINDS IN WAKE
OF COLD FRONT. MARGINAL SCA GUSTS ARE POSSIBLE ON ALL WATERS TUE
NIGHT IN WAKE OF COLD FRONT...BUT BETTER CHANCE ON ALL NEARSHORE
WATERS ON WEDNESDAY. SCA SWELLS GRADUALLY SUBSIDE ON THE OCEAN WED
INTO WED NIGHT.
SUB SCA CONDS LIKELY THU AND FRI AS HIGH PRESSURE BUILDS OVER THE
WATERS.
&&
.HYDROLOGY...
NO SIGNIFICANT WIDESPREAD RAINFALL IS EXPECTED THROUGH FRIDAY.
A FEW LOCALLY HEAVIER SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TUESDAY WITH BASIN AVERAGE QPF LESS THAN A QUARTER INCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 11 AM EDT TUESDAY FOR ANZ345-350-353-
355.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EDT
TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MET/TONGUE/NV
NEAR TERM...TONGUE
SHORT TERM...MET/TONGUE
LONG TERM...NV
AVIATION...DS
MARINE...MET/TONGUE/NV
HYDROLOGY...MET/NV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
655 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ANA WILL MOVE NORTHEAST AND OFFSHORE
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH OUR AREA TUESDAY NIGHT...
WITH A SECONDARY COLD FRONT FOLLOWING ON WEDNESDAY. HIGH PRESSURE
WILL MOVE INTO OUR REGION FROM THE NORTHWEST ON THURSDAY...AND
PASS OFFSHORE ON FRIDAY. A WARM FRONT IS FORECAST TO APPROACH FROM
THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
630 PM ESTF: LOWERED POPS FURTHER THROUGH 09Z TO ALMOST NO MENTION
EXCEPT EXTREME SOUTHEAST. ADJUSTED TEMPS SLIGHTLY MORE THIS EVE
BUT NO OVERALL IMPACT ON HUMID WARM MINS.
550 PM ESTF EARLY UPDATE: SLIGHT ADJUSTMENTS EVENING TEMPS TRENDS
AND WITHDREW LIGHTNING FROM THE FCST. APPEARS TO BE STABILIZING AT
22Z. WE MAY HAVE TO BOOST POPS THIS EVENING ALONG THE SNJ COAST
AND DE COASTS BUT NO CERTAINTY ATTM DESPITE THE RADAR APPEARANCE.
BELOW FROM 330 PM.
THE WATER VAPOR IMAGERY SHOWS A PERSISTENT RIDGE ALOFT ACROSS THE
EAST, HOWEVER IT IS GRADUALLY WEAKENING. THE REMNANTS OF TROPICAL
STORM ANA IS OVER EASTERN VIRGINIA THIS AFTERNOON AND IT IS DRIFTING
NORTHEAST. MEANWHILE, A LARGE TROUGH REMAINS ACROSS THE PLAINS.
THE LAPS DATA INDICATES THAT THE SURFACE-BASED INSTABILITY IS
BETWEEN ABOUT 1000-1500 J/KG ACROSS THE AREA. THERE IS NOT A LOT OF
FORCING, HOWEVER IT APPEARS THAT JUST ENOUGH LOW-LEVEL CONVERGENCE
IS RESULTING IN A BAND OF SOME SHOWERS AND ISOLATED THUNDER ACROSS
PORTIONS OF THE AREA. THESE STARTED IN SOUTHERN NEW JERSEY AND THEN
EXPANDED SOME AS THEY LIFTED NORTHWESTWARD. IT APPEARS THAT JUST
BRIEF DOWNPOURS AND SOME LIGHTNING IS OCCURRING, WHICH THE REGION
NEEDS THE RAINFALL. THIS IS EXPECTED TO CONTINUE THROUGH ABOUT EARLY
EVENING GIVEN LINGERING INSTABILITY AND THE PRESENCE OF PVA FROM
WHAT WAS TROPICAL STORM ANA. IT IS POSSIBLE THAT SOME REDEVELOPMENT
OCCURS FROM ABOUT INTERSTATE 95 ON EASTWARD THIS EVENING AS THE
LEFTOVER CENTER OF ANA TRACKS NEARBY. THE RAP AND HRRR HAVE BEEN
HINTING AT THIS POTENTIAL. THEREFORE WE WILL CARRY SOME SLIGHT CHC
TO LOW CHC POPS FOR ISOLATED/SCATTERED ACTIVITY. WE ALSO ARE
CARRYING SLIGHT CHC POPS FOR A TIME OVERNIGHT ACROSS THE NORTHWEST
ZONES AS CONVECTION FROM THE WEST SHOULD BE WEAKENING WITH AN
EASTWARD EXTENT.
THE NEXT ITEM IS LOW CLOUDS AND FOG. THE AIRMASS REMAINS MOIST AND
WITH THE INVERSION STRENGTHENING ONCE AGAIN AS THE BOUNDARY LAYER
COOLS, STRATUS SHOULD DEVELOP. THERE ARE SOME POCKETS OF LOWER
CLOUDS STILL LINGERING THIS AFTERNOON. WHILE SOME FOG IS EXPECTED,
IT MAY NOT BE ALL THAT DENSE GIVEN THE FLOW IS MORE FROM THE SOUTH
AND SOUTHWEST. IN ADDITION, A WEAK COLD FRONT WILL BE APPROACHING
TOWARD DAYBREAK. WE WILL CARRY THE MOST FOG MENTION CLOSEST TO THE
COAST BUT HOLD OFF ON A DENSE FOG ADVISORY GIVEN LESS CONFIDENCE.
LOW TEMPERATURES WERE MOSTLY A NAM/GFS MOS BLEND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL BE MOVING ACROSS THE GREAT LAKES AND INTO
THE NORTHEAST DURING THE COURSE OF TUESDAY. THIS WILL DRIVE SURFACE
LOW PRESSURE WELL TO OUR NORTH, HOWEVER AN ASSOCIATED COLD FRONT
WILL MOVE THROUGH. IT APPEARS THAT AN INITIAL DEW POINT BOUNDARY
MOVES THROUGH DURING THE MORNING TO MIDDAY HOURS WITH A DROP IN THE
DEW POINTS. THE TRUE AIRMASS CHANGE LOOKS TO HOLD OFF UNTIL LATE IN
THE DAY AND BEYOND. THERE MAY NOT BE MUCH LIFT TO SUPPORT
CONVECTION, PLUS THE AIRMASS IS FORECAST TO BE DRYING OUT THROUGH
THE DAY. THEREFORE WE KEPT MUCH OF THE DAY AND THE CWA DRY DESPITE
THE FRONTAL PASSAGE AND INCOMING UPPER-LEVEL TROUGH.
THERE SHOULD BE SOME STRATUS AND FOG EARLY, HOWEVER THE GUIDANCE
GENERALLY IS BRINGING IN ENOUGH DRYING EARLY TO ALLOW FOR THIS TO
QUICKLY DISSIPATE. THE FORECAST SOUNDINGS SHOW THIS DISTINCT DRYING,
AND ALSO THE BOUNDARY LAYER BECOMING WELL MIXED. AS THE PRESSURE
GRADIENT TIGHTENS AND THE FLOW INCREASES SOME, A BREEZY AFTERNOON IS
ANTICIPATED.
AS FOR THE HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND THEN
ADJUSTED UPWARD A LITTLE FOR SOME AREAS GIVEN THE DRYING WHICH
SHOULD HELP BOOST TEMPERATURES WELL INTO THE 80S FOR MANY
LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
MID-LEVEL S/WV TROUGH MOVES THRU THE NORTHEAST CONUS ON WED. FLOW
IS THEN MORE ZONAL OUT OF THE W/NW WITH SEVERAL S/WV DISTURBANCES
TRAVERSING IT THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND. FOR
THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...RIDGING MAY
TRY TO BUILD ALONG THE EAST COAST. IN GENERAL...FAIR WX EXPECTED
WED THRU FRI WITH HIGH PRESSURE AND TEMPS NEAR SEASONABLE LEVELS.
THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY WITH REGARD TO THE
EVOLUTION OF THE PATTERN OVER THE NORTHEAST CONUS. GENERAL MODEL
CONSENSUS SLOWS THE NORTHWARD ADVANCE OF A WARM FRONT AS THE MID-
LEVEL FLOW BECOMES PARALLEL TO IT. BOTH THE GFS AND ECMWF DEVELOP
SEVERAL WAVES OF LOW PRESSURE ALONG THIS BOUNDARY...WHILE THE UK
AND CANADIAN SHOW A MORE DIFFUSE BOUNDARY. NEVERTHELESS...CHANCE
FOR CONVECTION INCREASES DURING THIS TIME FRAME AND TEMPERATURES
TREND ABOVE AVERAGE.
DAILIES...
TUE NIGHT...COLD FRONT PROGGED TO MOVE OFFSHORE EARLY WITH ANY
SHRA/TSRA ENDING BY MIDNIGHT. POST-FRONTAL COLUMN DRIES QUICKLY
WITH CLEARING SKIES. COLD AIR ADVECTION WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES WHICH SHOULD LEAD TO WIND INITIALLY SCT GUSTS
UP TO 25 KNOTS, POSSIBLY BECOMING WIDESPREAD AFTER MIDNIGHT.
WED AND THU...FAIR WEATHER. SOME HIGH CLOUDS POSSIBLE EACH DAY
WITH THE UPPER JET NEARBY...WHILE MODEL SOUNDINGS INDICATE MORE
SCATTERED CU ON WED AS CONVECTIVE TEMPS ARE REACHED ALONG WITH
LOW-LEVEL MOISTURE TRAPPED BELOW SUBSIDENCE INVERSION. NW FLOW
BOTH DAYS...W/THE POTENTIAL FOR GUSTS OF 25 KNOTS ON WED AFTN.
THE GRADIENT SHOULD RELAX ENOUGH ON THU FOR SEA-BREEZES ALONG
THE SHORE BY THURSDAY.
FRI...HIGH PRES MOVES OFFSHORE LEADING TO A SOUTHERLY FLOW. A
WARM FRONT APPROACHES FROM THE WEST ALONG WITH SOME PRECIP...
BUT THE BULK OF THIS SHOULD REMAIN TO OUR WEST ALONG W/DEEP
MOIST AND BEST DYNAMICS. ATTM...CARRIED SLIGHT CHC POPS OVR
THE WESTERN CWA.
SAT THRU MON...FEEL THE UK/CANADIAN SOLUTION MOST REALISTIC
FOR THIS TIME FRAME...WHICH FEATURES A GRADUALLY MOISTENING
COLUMN DUE TO RETURN SOUTHWEST FLOW AROUND HIGH PRES MOVING
OFFSHORE. A DIFFUSE BOUNDARY IN THE VICINITY WOULD PROVIDE A
FOCUS FOR CONVECTION. THIS BOUNDARY MAY BECOME A COLD FRONT
IN THE SUN-MON TIME FRAME AND MOVE THRU THE REGION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...MAINLY VFR WITH ISOLATED EVENING SHOWERS, MAINLY NJ.
CEILINGS LOWERING TO MVFR/IFR WITH ANOTHER ROUND OF STRATUS
/LOCAL FOG/ OVERNIGHT...MAINLY I95 EASTWARD. THE TIMING OF THE
STRATUS IS OF LOWER CONFIDENCE, HOWEVER IT SHOULD HAPPEN FAIRLY
QUICKLY DURING THE EVENING ESPECIALLY CLOSER TO THE COAST.
SOUTHERLY WINDS NEAR 5 KNOTS.
LIFR PATCHY DENSE FOG POSSIBLY VCNTY KRDG IN THE 04Z-10Z TIME
FRAME.
GUSTY SOUTH WINDS 15-20 KT AT 22Z BECOME LIGHT WIND ALL NIGHT
AFTER 00Z/12...FIRST FROM THE SOUTH, THEN AFTER 05Z FROM THE
WEST OR SOUTHWEST.
TUESDAY...ANY LOW CLOUDS AND SOME FOG DISSIPATE BY 13Z, THEN VFR
SCT CLOUDS AOA 4000 FT. WEST- SOUTHWEST WINDS INCREASING TO NEAR
15 KNOTS WITH GUSTS UP TO 25 KNOTS.
OUTLOOK...
TUE NIGHT...MVFR POSSIBLE IN SHRA/TSRA MAINLY BEFORE MIDNIGHT.
NW WIND GUSTS NEAR 25 KT BECOMING INCREASINGLY WIDESPREAD DURING
THE NIGHT.
WED THRU FRI...VFR CONDITIONS EXPECTED. NW WIND GUSTS UP TO 25
KNOTS WED AFTN.
SAT...MVFR POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
A SOUTHERLY FLOW WILL BE MAINTAINED THROUGH TUESDAY, WITH A
SOUTHEAST WIND THIS AFTERNOON NEARSHORE AND UP DELAWARE BAY. A SHIFT
MORE FROM THE SOUTHWEST SHOULD OCCUR TUESDAY AS A WEAK FRONT MOVES
THROUGH BY LATE MORNING, THEN A SECONDARY FRONT ARRIVES LATE IN THE
DAY. MEANWHILE, THE REMNANTS OF TROPICAL DEPRESSION ANA WILL SLIDE
NEARBY TONIGHT. THE COMBINATION OF THE SOUTHERLY FLOW AND THE
PASSING SYSTEM SHOULD BUILD THE SEAS TO AROUND 5 FEET TONIGHT AND
TUESDAY ON THE COASTAL WATERS. THE WAVEWATCH GUIDANCE COULD BE A
LITTLE HIGH THOUGH WITH THE SEAS. THERE MAY BE SOME MARINE FOG ONCE
AGAIN TONIGHT GIVEN THE RATHER WARM AND MOIST AIRMASS OVER THE
COLDER WATERS, HOWEVER THE FLOW IS MORE SOUTH-SOUTHWEST SO THIS MAY
RESULT IN THE MAIN FOG AREA TO OUR NORTHEAST. AS A RESULT, WE WILL
CARRY A FOG MENTION BUT HOLD OFF ON A DENSE FOG ADVISORY ATTM. FOR
TUESDAY, THE FLOW INCREASES AND GUSTS TO 25 KNOTS LOOK TO OCCUR
MAINLY NEARSHORE WHERE THE BEST MIXING WILL BE. THEREFORE, WE WILL
MAINTAIN THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS MAINLY FOR
ELEVATED SEAS TONIGHT AND TUESDAY. WE HELD OFF ON A SMALL CRAFT
ADVISORY FOR DELAWARE BAY UNTIL TUESDAY NIGHT.
OUTLOOK...
TUE NIGHT THRU WED...SCA FOR WINDS AND SEAS IS NOW EXTENDED
THRU 10Z WED. STRONG, POST-FRONTAL COLD AIR ADVECTION REGIME
OVER WARMER SEA SURFACE TEMPERATURES WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES AND EFFECTIVE MOMENTUM TRANSFER IN SFC-900
HPA LAYER. EXPECT BOTH NW WINDS AND SEAS MEETING SCA LEVELS.
LOW PROBABILITY OF SCT GUSTS 35 KTS IN THE 10 PM TUESDAY TO 2 AM
WEDNESDAY TIME FRAME.
WED NIGHT THRU SAT...SUB-SCA WINDS AND SEAS ANTICIPATED ATTM.
&&
.FIRE WEATHER...
AN ENHANCED THREAT OF WILDFIRE SPREAD IS POSSIBLE TUESDAY AND
WEDNESDAY.
FOR TUESDAY, WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST UP TO 30
MPH ESPECIALLY IN THE AFTERNOON. THE RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP INTO THE 30S DURING THE AFTERNOON. SOME WETTING
HAS OCCURRED IN SPOTS TODAY /MONDAY/ HOWEVER THE FUELS ARE RATHER
DRY.
FOR WEDNESDAY, A NORTHWEST WIND IS EXPECTED AND GUSTS OF 20 TO 30
MPH ARE ANTICIPATED. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP
AROUND 30 PERCENT DURING THE AFTERNOON. APPEARS TO DESTINED FOR
SPS AT A MINIMUM FOR WEDNESDAY. THIS IN PART DUE TO LESS THAN 5
PERCENT OF NORMAL MAY PCPN IN THE NE PART OF PA AND NW PART OF NJ
AND 5 TO 25 PCT OF NORMAL ELSEWHERE.
ACTUAL VALUES UNDER ONE QUARTER INCH SEEM TO BE WIDESPREAD SINCE
ABOUT THE 23RD OF APRIL AND TEMPS ARE AVGING 5 TO 8 DEGS ABOVE
NORMAL FOR THE FIRST 10 DAYS OF MAY!
10 HR FUELS ARE ALREADY DRY EVEN IN THE HUMID CONDITIONS AT 640
PM THIS EVENING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ450>453.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ454-455.
SMALL CRAFT ADVISORY FROM 8 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...DRAG/GORSE 654
SHORT TERM...GORSE
LONG TERM...FRANCK
AVIATION...DRAG/FRANCK/GORSE 654
MARINE...DRAG/FRANCK/GORSE/ROBERTSON 654
FIRE WEATHER...654
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
612 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ANA WILL MOVE NORTHEAST AND OFFSHORE
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH OUR AREA TUESDAY NIGHT...
WITH A SECONDARY COLD FRONT FOLLOWING ON WEDNESDAY. HIGH PRESSURE
WILL MOVE INTO OUR REGION FROM THE NORTHWEST ON THURSDAY...AND
PASS OFFSHORE ON FRIDAY. A WARM FRONT IS FORECAST TO APPROACH FROM
THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
550 PM ESTF EARLY UPDATE: SLIGHT ADJUSTMENTS EVENING TEMPS TRENDS
AND WITHDREW LIGHTNING FROM THE FCST. APPEARS TO BE STABILIZING AT
22Z. WE MAY HAVE TO BOOST POPS THIS EVENING ALONG THE SNJ COAST
AND DE COASTS BUT NO CERTAINTY ATTM DESPITE THE RADAR APPEARANCE.
BELOW FROM 330 PM.
THE WATER VAPOR IMAGERY SHOWS A PERSISTENT RIDGE ALOFT ACROSS THE
EAST, HOWEVER IT IS GRADUALLY WEAKENING. THE REMNANTS OF TROPICAL
STORM ANA IS OVER EASTERN VIRGINIA THIS AFTERNOON AND IT IS DRIFTING
NORTHEAST. MEANWHILE, A LARGE TROUGH REMAINS ACROSS THE PLAINS.
THE LAPS DATA INDICATES THAT THE SURFACE-BASED INSTABILITY IS
BETWEEN ABOUT 1000-1500 J/KG ACROSS THE AREA. THERE IS NOT A LOT OF
FORCING, HOWEVER IT APPEARS THAT JUST ENOUGH LOW-LEVEL CONVERGENCE
IS RESULTING IN A BAND OF SOME SHOWERS AND ISOLATED THUNDER ACROSS
PORTIONS OF THE AREA. THESE STARTED IN SOUTHERN NEW JERSEY AND THEN
EXPANDED SOME AS THEY LIFTED NORTHWESTWARD. IT APPEARS THAT JUST
BRIEF DOWNPOURS AND SOME LIGHTNING IS OCCURRING, WHICH THE REGION
NEEDS THE RAINFALL. THIS IS EXPECTED TO CONTINUE THROUGH ABOUT EARLY
EVENING GIVEN LINGERING INSTABILITY AND THE PRESENCE OF PVA FROM
WHAT WAS TROPICAL STORM ANA. IT IS POSSIBLE THAT SOME REDEVELOPMENT
OCCURS FROM ABOUT INTERSTATE 95 ON EASTWARD THIS EVENING AS THE
LEFTOVER CENTER OF ANA TRACKS NEARBY. THE RAP AND HRRR HAVE BEEN
HINTING AT THIS POTENTIAL. THEREFORE WE WILL CARRY SOME SLIGHT CHC
TO LOW CHC POPS FOR ISOLATED/SCATTERED ACTIVITY. WE ALSO ARE
CARRYING SLIGHT CHC POPS FOR A TIME OVERNIGHT ACROSS THE NORTHWEST
ZONES AS CONVECTION FROM THE WEST SHOULD BE WEAKENING WITH AN
EASTWARD EXTENT.
THE NEXT ITEM IS LOW CLOUDS AND FOG. THE AIRMASS REMAINS MOIST AND
WITH THE INVERSION STRENGTHENING ONCE AGAIN AS THE BOUNDARY LAYER
COOLS, STRATUS SHOULD DEVELOP. THERE ARE SOME POCKETS OF LOWER
CLOUDS STILL LINGERING THIS AFTERNOON. WHILE SOME FOG IS EXPECTED,
IT MAY NOT BE ALL THAT DENSE GIVEN THE FLOW IS MORE FROM THE SOUTH
AND SOUTHWEST. IN ADDITION, A WEAK COLD FRONT WILL BE APPROACHING
TOWARD DAYBREAK. WE WILL CARRY THE MOST FOG MENTION CLOSEST TO THE
COAST BUT HOLD OFF ON A DENSE FOG ADVISORY GIVEN LESS CONFIDENCE.
LOW TEMPERATURES WERE MOSTLY A NAM/GFS MOS BLEND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL BE MOVING ACROSS THE GREAT LAKES AND INTO
THE NORTHEAST DURING THE COURSE OF TUESDAY. THIS WILL DRIVE SURFACE
LOW PRESSURE WELL TO OUR NORTH, HOWEVER AN ASSOCIATED COLD FRONT
WILL MOVE THROUGH. IT APPEARS THAT AN INITIAL DEW POINT BOUNDARY
MOVES THROUGH DURING THE MORNING TO MIDDAY HOURS WITH A DROP IN THE
DEW POINTS. THE TRUE AIRMASS CHANGE LOOKS TO HOLD OFF UNTIL LATE IN
THE DAY AND BEYOND. THERE MAY NOT BE MUCH LIFT TO SUPPORT
CONVECTION, PLUS THE AIRMASS IS FORECAST TO BE DRYING OUT THROUGH
THE DAY. THEREFORE WE KEPT MUCH OF THE DAY AND THE CWA DRY DESPITE
THE FRONTAL PASSAGE AND INCOMING UPPER-LEVEL TROUGH.
THERE SHOULD BE SOME STRATUS AND FOG EARLY, HOWEVER THE GUIDANCE
GENERALLY IS BRINGING IN ENOUGH DRYING EARLY TO ALLOW FOR THIS TO
QUICKLY DISSIPATE. THE FORECAST SOUNDINGS SHOW THIS DISTINCT DRYING,
AND ALSO THE BOUNDARY LAYER BECOMING WELL MIXED. AS THE PRESSURE
GRADIENT TIGHTENS AND THE FLOW INCREASES SOME, A BREEZY AFTERNOON IS
ANTICIPATED.
AS FOR THE HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND THEN
ADJUSTED UPWARD A LITTLE FOR SOME AREAS GIVEN THE DRYING WHICH
SHOULD HELP BOOST TEMPERATURES WELL INTO THE 80S FOR MANY
LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
MID-LEVEL S/WV TROUGH MOVES THRU THE NORTHEAST CONUS ON WED. FLOW
IS THEN MORE ZONAL OUT OF THE W/NW WITH SEVERAL S/WV DISTURBANCES
TRAVERSING IT THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND. FOR
THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...RIDGING MAY
TRY TO BUILD ALONG THE EAST COAST. IN GENERAL...FAIR WX EXPECTED
WED THRU FRI WITH HIGH PRESSURE AND TEMPS NEAR SEASONABLE LEVELS.
THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY WITH REGARD TO THE
EVOLUTION OF THE PATTERN OVER THE NORTHEAST CONUS. GENERAL MODEL
CONSENSUS SLOWS THE NORTHWARD ADVANCE OF A WARM FRONT AS THE MID-
LEVEL FLOW BECOMES PARALLEL TO IT. BOTH THE GFS AND ECMWF DEVELOP
SEVERAL WAVES OF LOW PRESSURE ALONG THIS BOUNDARY...WHILE THE UK
AND CANADIAN SHOW A MORE DIFFUSE BOUNDARY. NEVERTHELESS...CHANCE
FOR CONVECTION INCREASES DURING THIS TIME FRAME AND TEMPERATURES
TREND ABOVE AVERAGE.
DAILIES...
TUE NIGHT...COLD FRONT PROGGED TO MOVE OFFSHORE EARLY WITH ANY
SHRA/TSRA ENDING BY MIDNIGHT. POST-FRONTAL COLUMN DRIES QUICKLY
WITH CLEARING SKIES. COLD AIR ADVECTION WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES WHICH MAY LEAD TO WIND GUSTS UP TO 25 KNOTS
PRIOR TO MIDNIGHT...DIMINISHING THEREAFTER.
WED AND THU...FAIR WEATHER. SOME HIGH CLOUDS POSSIBLE EACH DAY
WITH THE UPPER JET NEARBY...WHILE MODEL SOUNDINGS INDICATE MORE
SCATTERED CU ON WED AS CONVECTIVE TEMPS ARE REACHED ALONG WITH
LOW-LEVEL MOISTURE TRAPPED BELOW SUBSIDENCE INVERSION. NW FLOW
BOTH DAYS...W/THE POTENTIAL FOR GUSTS OF 25 KNOTS ON WED AFTN.
THE GRADIENT SHOULD RELAX ENOUGH ON THU FOR SEA-BREEZES ALONG
THE SHORE BY THURSDAY.
FRI...HIGH PRES MOVES OFFSHORE LEADING TO A SOUTHERLY FLOW. A
WARM FRONT APPROACHES FROM THE WEST ALONG WITH SOME PRECIP...
BUT THE BULK OF THIS SHOULD REMAIN TO OUR WEST ALONG W/DEEP
MOIST AND BEST DYNAMICS. ATTM...CARRIED SLIGHT CHC POPS OVR
THE WESTERN CWA.
SAT THRU MON...FEEL THE UK/CANADIAN SOLUTION MOST REALISTIC
FOR THIS TIME FRAME...WHICH FEATURES A GRADUALLY MOISTENING
COLUMN DUE TO RETURN SOUTHWEST FLOW AROUND HIGH PRES MOVING
OFFSHORE. A DIFFUSE BOUNDARY IN THE VICINITY WOULD PROVIDE A
FOCUS FOR CONVECTION. THIS BOUNDARY MAY BECOME A COLD FRONT
IN THE SUN-MON TIME FRAME AND MOVE THRU THE REGION.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...MAINLY VFR WITH ISOLATED EVENING SHOWERS, MAINLY NJ.
CEILINGS LOWERING TO MVFR/IFR WITH ANOTHER ROUND OF STRATUS
/LOCAL FOG/ OVERNIGHT...MAINLY I95 EASTWARD. THE TIMING OF THE
STRATUS IS OF LOWER CONFIDENCE, HOWEVER IT SHOULD HAPPEN FAIRLY
QUICKLY DURING THE EVENING ESPECIALLY CLOSER TO THE COAST.
SOUTHERLY WINDS NEAR 5 KNOTS.
LIFR PATCHY DENSE FOG POSSIBLY VCNTY KRDG IN THE 04Z-10Z TIME
FRAME.
GUSTY SOUTH WINDS 15-20 KT AT 22Z BECOME LIGHT WIND ALL NIGHT
AFTER 00Z/12...FIRST FROM THE SOUTH, THEN AFTER 05Z FROM THE
WEST OR SOUTHWEST.
TUESDAY...ANY LOW CLOUDS AND SOME FOG DISSIPATE BY 13Z, THEN VFR
SCT CLOUDS AOA 4000 FT. WEST- SOUTHWEST WINDS INCREASING TO NEAR
15 KNOTS WITH GUSTS UP TO 25 KNOTS.
OUTLOOK...
TUE NIGHT...MVFR POSSIBLE IN SHRA/TSRA MAINLY BEFORE MIDNIGHT.
NW WIND GUSTS NEAR 25 KT BECOMING INCREASINGLY WIDESPREAD DURING
THE NIGHT.
WED THRU FRI...VFR CONDITIONS EXPECTED. NW WIND GUSTS UP TO 25
KNOTS WED AFTN.
SAT...MVFR POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
A SOUTHERLY FLOW WILL BE MAINTAINED THROUGH TUESDAY, WITH A
SOUTHEAST WIND THIS AFTERNOON NEARSHORE AND UP DELAWARE BAY. A SHIFT
MORE FROM THE SOUTHWEST SHOULD OCCUR TUESDAY AS A WEAK FRONT MOVES
THROUGH BY LATE MORNING, THEN A SECONDARY FRONT ARRIVES LATE IN THE
DAY. MEANWHILE, THE REMNANTS OF TROPICAL DEPRESSION ANA WILL SLIDE
NEARBY TONIGHT. THE COMBINATION OF THE SOUTHERLY FLOW AND THE
PASSING SYSTEM SHOULD BUILD THE SEAS TO AROUND 5 FEET TONIGHT AND
TUESDAY ON THE COASTAL WATERS. THE WAVEWATCH GUIDANCE COULD BE A
LITTLE HIGH THOUGH WITH THE SEAS. THERE MAY BE SOME MARINE FOG ONCE
AGAIN TONIGHT GIVEN THE RATHER WARM AND MOIST AIRMASS OVER THE
COLDER WATERS, HOWEVER THE FLOW IS MORE SOUTH-SOUTHWEST SO THIS MAY
RESULT IN THE MAIN FOG AREA TO OUR NORTHEAST. AS A RESULT, WE WILL
CARRY A FOG MENTION BUT HOLD OFF ON A DENSE FOG ADVISORY ATTM. FOR
TUESDAY, THE FLOW INCREASES AND GUSTS TO 25 KNOTS LOOK TO OCCUR
MAINLY NEARSHORE WHERE THE BEST MIXING WILL BE. THEREFORE, WE WILL
MAINTAIN THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS MAINLY FOR
ELEVATED SEAS TONIGHT AND TUESDAY. WE HELD OFF ON A SMALL CRAFT
ADVISORY FOR DELAWARE BAY UNTIL TUESDAY NIGHT.
OUTLOOK...
TUE NIGHT THRU WED...SCA FOR WINDS AND SEAS IS NOW EXTENDED
THRU 10Z WED. STRONG, POST-FRONTAL COLD AIR ADVECTION REGIME
OVER WARMER SEA SURFACE TEMPERATURES WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES AND EFFECTIVE MOMENTUM TRANSFER IN SFC-900
HPA LAYER. EXPECT BOTH NW WINDS AND SEAS MEETING SCA LEVELS.
WED NIGHT THRU SAT...SUB-SCA WINDS AND SEAS ANTICIPATED ATTM.
&&
.FIRE WEATHER...
AN ENHANCED THREAT OF WILDFIRE SPREAD IS POSSIBLE TUESDAY AND
WEDNESDAY.
FOR TUESDAY, WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST UP TO 30
MPH ESPECIALLY IN THE AFTERNOON. THE RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP INTO THE 30S DURING THE AFTERNOON. SOME WETTING
HAS OCCURRED IN SPOTS TODAY /MONDAY/ HOWEVER THE FUELS ARE RATHER
DRY.
FOR WEDNESDAY, A NORTHWEST WIND IS EXPECTED AND GUSTS OF 20 TO 30
MPH ARE ANTICIPATED. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP
AROUND 30 PERCENT DURING THE AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ450>453.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ454-455.
SMALL CRAFT ADVISORY FROM 8 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...DRAG/GORSE 613
SHORT TERM...GORSE
LONG TERM...FRANCK
AVIATION...DRAG/FRANCK/GORSE 613
MARINE...DRAG/FRANCK/GORSE/ROBERTSON 613
FIRE WEATHER...
AREA FORECAST DISCUSSION...CORRECTED
NWS MOUNT HOLLY NJ
351 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF TROPICAL STORM ANA WILL MOVE NORTHEAST AND OFFSHORE
OVERNIGHT. A COLD FRONT WILL MOVE THROUGH OUR AREA TUESDAY NIGHT...
WITH A SECONDARY COLD FRONT FOLLOWING ON WEDNESDAY. HIGH PRESSURE
WILL MOVE INTO OUR REGION FROM THE NORTHWEST ON THURSDAY...AND
PASS OFFSHORE ON FRIDAY. A WARM FRONT IS FORECAST TO APPROACH FROM
THE SOUTHWEST OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE WATER VAPOR IMAGERY SHOWS A PERSISTENT RIDGE ALOFT ACROSS THE
EAST, HOWEVER IT IS GRADUALLY WEAKENING. THE REMNANTS OF TROPICAL
STORM ANA IS OVER EASTERN VIRGINIA THIS AFTERNOON AND IT IS DRIFTING
NORTHEAST. MEANWHILE, A LARGE TROUGH REMAINS ACROSS THE PLAINS.
THE LAPS DATA INDICATES THAT THE SURFACE-BASED INSTABILITY IS
BETWEEN ABOUT 1000-1500 J/KG ACROSS THE AREA. THERE IS NOT A LOT OF
FORCING, HOWEVER IT APPEARS THAT JUST ENOUGH LOW-LEVEL CONVERGENCE
IS RESULTING IN A BAND OF SOME SHOWERS AND ISOLATED THUNDER ACROSS
PORTIONS OF THE AREA. THESE STARTED IN SOUTHERN NEW JERSEY AND THEN
EXPANDED SOME AS THEY LIFTED NORTHWESTWARD. IT APPEARS THAT JUST
BRIEF DOWNPOURS AND SOME LIGHTNING IS OCCURRING, WHICH THE REGION
NEEDS THE RAINFALL. THIS IS EXPECTED TO CONTINUE THROUGH ABOUT EARLY
EVENING GIVEN LINGERING INSTABILITY AND THE PRESENCE OF PVA FROM
WHAT WAS TROPICAL STORM ANA. IT IS POSSIBLE THAT SOME REDEVELOPMENT
OCCURS FROM ABOUT INTERSTATE 95 ON EASTWARD THIS EVENING AS THE
LEFTOVER CENTER OF ANA TRACKS NEARBY. THE RAP AND HRRR HAVE BEEN
HINTING AT THIS POTENTIAL. THEREFORE WE WILL CARRY SOME SLIGHT CHC
TO LOW CHC POPS FOR ISOLATED/SCATTERED ACTIVITY. WE ALSO ARE
CARRYING SLIGHT CHC POPS FOR A TIME OVERNIGHT ACROSS THE NORTHWEST
ZONES AS CONVECTION FROM THE WEST SHOULD BE WEAKENING WITH AN
EASTWARD EXTENT.
THE NEXT ITEM IS LOW CLOUDS AND FOG. THE AIRMASS REMAINS MOIST AND
WITH THE INVERSION STRENGTHENING ONCE AGAIN AS THE BOUNDARY LAYER
COOLS, STRATUS SHOULD DEVELOP. THERE ARE SOME POCKETS OF LOWER
CLOUDS STILL LINGERING THIS AFTERNOON. WHILE SOME FOG IS EXPECTED,
IT MAY NOT BE ALL THAT DENSE GIVEN THE FLOW IS MORE FROM THE SOUTH
AND SOUTHWEST. IN ADDITION, A WEAK COLD FRONT WILL BE APPROACHING
TOWARD DAYBREAK. WE WILL CARRY THE MOST FOG MENTION CLOSEST TO THE
COAST BUT HOLD OFF ON A DENSE FOG ADVISORY GIVEN LESS CONFIDENCE.
LOW TEMPERATURES WERE MOSTLY A NAM/GFS MOS BLEND.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL BE MOVING ACROSS THE GREAT LAKES AND INTO
THE NORTHEAST DURING THE COURSE OF TUESDAY. THIS WILL DRIVE SURFACE
LOW PRESSURE WELL TO OUR NORTH, HOWEVER AN ASSOCIATED COLD FRONT
WILL MOVE THROUGH. IT APPEARS THAT AN INITIAL DEW POINT BOUNDARY
MOVES THROUGH DURING THE MORNING TO MIDDAY HOURS WITH A DROP IN THE
DEW POINTS. THE TRUE AIRMASS CHANGE LOOKS TO HOLD OFF UNTIL LATE IN
THE DAY AND BEYOND. THERE MAY NOT BE MUCH LIFT TO SUPPORT
CONVECTION, PLUS THE AIRMASS IS FORECAST TO BE DRYING OUT THROUGH
THE DAY. THEREFORE WE KEPT MUCH OF THE DAY AND THE CWA DRY DESPITE
THE FRONTAL PASSAGE AND INCOMING UPPER-LEVEL TROUGH.
THERE SHOULD BE SOME STRATUS AND FOG EARLY, HOWEVER THE GUIDANCE
GENERALLY IS BRINGING IN ENOUGH DRYING EARLY TO ALLOW FOR THIS TO
QUICKLY DISSIPATE. THE FORECAST SOUNDINGS SHOW THIS DISTINCT DRYING,
AND ALSO THE BOUNDARY LAYER BECOMING WELL MIXED. AS THE PRESSURE
GRADIENT TIGHTENS AND THE FLOW INCREASES SOME, A BREEZY AFTERNOON IS
ANTICIPATED.
AS FOR THE HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND THEN
ADJUSTED UPWARD A LITTLE FOR SOME AREAS GIVEN THE DRYING WHICH
SHOULD HELP BOOST TEMPERATURES WELL INTO THE 80S FOR MANY
LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
OVERVIEW...
MID-LEVEL S/WV TROUGH MOVES THRU THE NORTHEAST CONUS ON WED. FLOW
IS THEN MORE ZONAL OUT OF THE W/NW WITH SEVERAL S/WV DISTURBANCES
TRAVERSING IT THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND. FOR
THE LATTER HALF OF THE WEEKEND INTO EARLY NEXT WEEK...RIDGING MAY
TRY TO BUILD ALONG THE EAST COAST. IN GENERAL...FAIR WX EXPECTED
WED THRU FRI WITH HIGH PRESSURE AND TEMPS NEAR SEASONABLE LEVELS.
THEREAFTER...THERE IS CONSIDERABLE UNCERTAINTY WITH REGARD TO THE
EVOLUTION OF THE PATTERN OVER THE NORTHEAST CONUS. GENERAL MODEL
CONSENSUS SLOWS THE NORTHWARD ADVANCE OF A WARM FRONT AS THE MID-
LEVEL FLOW BECOMES PARALLEL TO IT. BOTH THE GFS AND ECMWF DEVELOP
SEVERAL WAVES OF LOW PRESSURE ALONG THIS BOUNDARY...WHILE THE UK
AND CANADIAN SHOW A MORE DIFFUSE BOUNDARY. NEVERTHELESS...CHANCE
FOR CONVECTION INCREASES DURING THIS TIME FRAME AND TEMPERATURES
TREND ABOVE AVERAGE.
DAILIES...
TUE NIGHT...COLD FRONT PROGGED TO MOVE OFFSHORE EARLY WITH ANY
SHRA/TSRA ENDING BY MIDNIGHT. POST-FRONTAL COLUMN DRIES QUICKLY
WITH CLEARING SKIES. COLD AIR ADVECTION WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES WHICH MAY LEAD TO WIND GUSTS UP TO 25 KNOTS
PRIOR TO MIDNIGHT...DIMINISHING THEREAFTER.
WED AND THU...FAIR WEATHER. SOME HIGH CLOUDS POSSIBLE EACH DAY
WITH THE UPPER JET NEARBY...WHILE MODEL SOUNDINGS INDICATE MORE
SCATTERED CU ON WED AS CONVECTIVE TEMPS ARE REACHED ALONG WITH
LOW-LEVEL MOISTURE TRAPPED BELOW SUBSIDENCE INVERSION. NW FLOW
BOTH DAYS...W/THE POTENTIAL FOR GUSTS OF 25 KNOTS ON WED AFTN.
THE GRADIENT SHOULD RELAX ENOUGH ON THU FOR SEA-BREEZES ALONG
THE SHORE BY THURSDAY.
FRI...HIGH PRES MOVES OFFSHORE LEADING TO A SOUTHERLY FLOW. A
WARM FRONT APPROACHES FROM THE WEST ALONG WITH SOME PRECIP...
BUT THE BULK OF THIS SHOULD REMAIN TO OUR WEST ALONG W/DEEP
MOIST AND BEST DYNAMICS. ATTM...CARRIED SLIGHT CHC POPS OVR
THE WESTERN CWA.
SAT THRU MON...FEEL THE UK/CANADIAN SOLUTION MOST REALISTIC
FOR THIS TIME FRAME...WHICH FEATURES A GRADUALLY MOISTENING
COLUMN DUE TO RETURN SOUTHWEST FLOW AROUND HIGH PRES MOVING
OFFSHORE. A DIFFUSE BOUNDARY IN THE VICINITY WOULD PROVIDE A
FOCUS FOR CONVECTION. THIS BOUNDARY MAY BECOME A COLD FRONT
IN THE SUN-MON TIME FRAME AND MOVE THRU THE REGION.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF THIS AFTERNOON...MAINLY VFR CEILINGS. SOUTHERLY WINDS AROUND
10 KNOTS, WITH SOME LOCAL GUSTS UP TO 20 KNOTS AT TIMES. SOME
SHOWERS AND/OR THUNDERSTORMS AROUND.
TONIGHT...MAINLY VFR WITH AN EVENING SHOWER OR THUNDERSTORM AROUND,
THEN CEILINGS LOWERING TO MVFR/IFR WITH ANOTHER ROUND OF STRATUS
/LOCAL FOG/ OVERNIGHT. THE TIMING OF THE STRATUS IS OF LOWER
CONFIDENCE, HOWEVER IT COULD HAPPEN FAIRLY QUICKLY DURING THE
EVENING ESPECIALLY CLOSER TO THE COAST. SOUTHERLY WINDS NEAR 5
KNOTS.
TUESDAY...LOW CLOUDS AND SOME FOG EARLY, THEN VFR. WEST-SOUTHWEST
WINDS INCREASING TO NEAR 15 KNOTS WITH GUSTS UP TO 25 KNOTS.
OUTLOOK...
TUE NIGHT...MVFR POSSIBLE IN SHRA/TSRA MAINLY BEFORE MIDNIGHT.
WED THRU FRI...VFR CONDITIONS EXPECTED. NW WIND GUSTS UP TO 25
KNOTS WED AFTN.
SAT...MVFR POSSIBLE IN SHRA/TSRA.
&&
.MARINE...
A SOUTHERLY FLOW WILL BE MAINTAINED THROUGH TUESDAY, WITH A
SOUTHEAST WIND THIS AFTERNOON NEARSHORE AND UP DELAWARE BAY. A SHIFT
MORE FROM THE SOUTHWEST SHOULD OCCUR TUESDAY AS A WEAK FRONT MOVES
THROUGH BY LATE MORNING, THEN A SECONDARY FRONT ARRIVES LATE IN THE
DAY. MEANWHILE, THE REMNANTS OF TROPICAL DEPRESSION ANA WILL SLIDE
NEARBY TONIGHT. THE COMBINATION OF THE SOUTHERLY FLOW AND THE
PASSING SYSTEM SHOULD BUILD THE SEAS TO AROUND 5 FEET TONIGHT AND
TUESDAY ON THE COASTAL WATERS. THE WAVEWATCH GUIDANCE COULD BE A
LITTLE HIGH THOUGH WITH THE SEAS. THERE MAY BE SOME MARINE FOG ONCE
AGAIN TONIGHT GIVEN THE RATHER WARM AND MOIST AIRMASS OVER THE
COLDER WATERS, HOWEVER THE FLOW IS MORE SOUTH-SOUTHWEST SO THIS MAY
RESULT IN THE MAIN FOG AREA TO OUR NORTHEAST. AS A RESULT, WE WILL
CARRY A FOG MENTION BUT HOLD OFF ON A DENSE FOG ADVISORY ATTM. FOR
TUESDAY, THE FLOW INCREASES AND GUSTS TO 25 KNOTS LOOK TO OCCUR
MAINLY NEARSHORE WHERE THE BEST MIXING WILL BE. THEREFORE, WE WILL
MAINTAIN THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS MAINLY FOR
ELEVATED SEAS TONIGHT AND TUESDAY. WE HELD OFF ON A SMALL CRAFT
ADVISORY FOR DELAWARE BAY UNTIL TUESDAY NIGHT.
OUTLOOK...
TUE NIGHT THRU WED...SCA FOR WINDS AND SEAS IS NOW EXTENDED
THRU 10Z WED. STRONG, POST-FRONTAL COLD AIR ADVECTION REGIME
OVER WARMER SEA SURFACE TEMPERATURES WILL LEAD TO STEEP LOW-
LEVEL LAPSE RATES AND EFFECTIVE MOMENTUM TRANSFER IN SFC-900
HPA LAYER. EXPECT BOTH NW WINDS AND SEAS MEETING SCA LEVELS.
WED NIGHT THRU SAT...SUB-SCA WINDS AND SEAS ANTICIPATED ATTM.
&&
.FIRE WEATHER...
AN ENHANCED THREAT OF WILDFIRE SPREAD IS POSSIBLE TUESDAY AND
WEDNESDAY.
FOR TUESDAY, WEST-SOUTHWEST WINDS ARE EXPECTED TO GUST UP TO 30
MPH ESPECIALLY IN THE AFTERNOON. THE RELATIVE HUMIDITY VALUES ARE
FORECAST TO DROP INTO THE 30S DURING THE AFTERNOON. SOME WETTING
HAS OCCURRED IN SPOTS TODAY /MONDAY/ HOWEVER THE FUELS ARE RATHER
DRY.
FOR WEDNESDAY, A NORTHWEST WIND IS EXPECTED AND GUSTS OF 20 TO 30
MPH ARE ANTICIPATED. RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP
AROUND 30 PERCENT DURING THE AFTERNOON.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ450>453.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ANZ454-455.
SMALL CRAFT ADVISORY FROM 8 PM TUESDAY TO 6 AM EDT WEDNESDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...GORSE
SHORT TERM...GORSE
LONG TERM...FRANCK
AVIATION...FRANCK/GORSE
MARINE...FRANCK/GORSE
FIRE WEATHER...FRANCK/GORSE
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
400 PM EDT MON MAY 11 2015
.REST OF TODAY...ISOLD SHOWERS HAVE POPPED UP ALONG ATLC SEA BREEZE
AND CONVERGENT BOUNDARIES OVER DUVAL...MARION AND PUTNAM COUNTIES.
SBCAPE ANALYSIS SHOW AROUND 1500J/KG INLAND TO 2500-3000 J/KG TOWARD
THE COAST WHERE DEWPOINTS HAVE RISEN QUICKLY BEHIND THE SEA BREEZE.
TEMPS ARE IN THE LOWER TO MID 90S INLAND AND MID TO UPPER 80S NEAR
THE COAST. ANTICIPATE AN UPTICK IN COVERAGE AND INTENSITY OF
CONVECTION THROUGH THE AFTN...AGAIN MAINLY FOCUSED INTERIOR NE FL
WITH A LESSER CHANCE OVER THE ERN SE GA ZONES. DRY AIR AND
SUBSIDENCE AROUND THE 10000-18000 FT LEVEL WILL HELP LIMIT COVERAGE
OF CONVECTION.
TONIGHT...ISOLD TO SCT SHOWERS AND STORMS EXPECTED TO CONTINUE
INLAND AREAS WHICH WILL GRADUALLY FADE WITH THE LOSS OF HEATING.
NONETHELESS...WITH HIGHER DEWPOINTS AND ANY LINGERING BOUNDARIES
SOME WEAK ISOLD CONVECTION MAY POP UP THROUGH LATE TONIGHT
BUT EXPECTED TO BE SHORT-LIVED. LOW TEMPS GENERALLY 65 TO 70.
VERY PATCHY LIGHT FOG POSSIBLE.
TUESDAY...LOW LEVEL HIGH PRES RIDGE WILL BE LOCATED OVER CENTRAL
FL AGAIN WITH A WEAK COLD FRONT MOVING INTO THE SE CONUS.
PRE-FRONTAL TROUGH OVER SE GA AND W AND E COAST SEA BREEZES WILL
INITIATE AFTN CONVECTION...MAINLY ISOLD IN COVERAGE WITH SCT
SHOWERS AND STORMS POSSIBLE INLAND NE FL WHERE HIGHER DEWPOINTS
ARE EXPECTED. HIGH TEMPS CONTINUE TO BE ABOVE NORMAL IN THE LOWER
TO MID 90S...MID TO UPPER 80S AT THE COAST.
.SHORT TERM (TUESDAY NIGHT THROUGH THURSDAY NIGHT)...
A COLD FRONT MOVING INTO THE SOUTHEASTERN STATES LATE TUESDAY WILL
LOSE SUPPORT ALOFT....AS BROAD RIDGING OVER THE GULF OF MEXICO
EXPANDS EASTWARD OVER THE FL PENINSULA. HOWEVER...THIS BOUNDARY
WILL SERVE AS A FOCUSING MECHANISM...IN CONCERT WITH MESOSCALE
BOUNDARIES...TO SPARK AT LEAST SCATTERED DIURNAL CONVECTION AS THE
FRONT SINKS SOUTHWARD TO THE FL/GA BORDER BY LATE WEDNESDAY AND
STALLS. SCATTERED EARLY EVENING CONVECTION OVER NORTH CENTRAL FL ON
TUESDAY WILL PUSH SLOWLY WESTWARD AND WANE BEFORE MIDNIGHT...WITH
ONLY ISOLATED EARLY EVENING ACTIVITY ELSEWHERE. LOWS WILL REMAIN
ABOVE NORMAL...WITH UPPER 60S INLAND TO LOWER 70S AT THE COAST.
A WEAK SURFACE PRESSURE PATTERN WILL PREVAIL AS THE FRONT MOVES
THROUGH SOUTHEAST GA ON WED...ALLOWING FOR THE ATLANTIC SEA BREEZE
TO MOVE WELL INLAND AND FOCUS MAINLY AFTERNOON AND EVENING
CONVECTION FOR LOCATIONS WEST OF INTERSTATE 95. WE WILL KEEP
SCATTERED POPS IN THE FORECAST FOR NOW...ALTHOUGH AFTERNOON RAIN
CHANCES MAY NEED TO BE INCREASED OVER INLAND NORTHEAST FL IN FUTURE
FORECASTS. A MORE ACTIVE ATLANTIC SEA BREEZE WILL KEEP HIGHS IN THE
80S FOR THE COASTAL COUNTIES ON WED...WITH LOWER 90S EXPECTED
INLAND...EXCEPT A FEW DEGREES COOLER BEHIND THE FRONT NORTH OF
WAYCROSS. EVENING ACTIVITY MAY LINGER OVER NORTH CENTRAL FL...WITH
SLIGHTLY COOLER AND DRIER AIR FILTERING INTO INLAND SOUTHEAST
GA...WHERE LOWS WILL FALL INTO THE 60S. LOWS SOUTH OF THE FRONT WILL
REMAIN IN THE UPPER 60S TO THE LOWER 70S.
SURFACE RIDGING WILL BUILD TO THE NORTH OF OUR REGION ON THURS AS
THE FRONT WASHES OUT OVER NORTHEAST FL...WITH DEEPENING EASTERLY LOW-
LEVEL FLOW FOCUSING ACTIVITY OVER INLAND AREAS...ESPECIALLY ALONG
THE I-75 CORRIDOR BY LATE AFTERNOON. WE WILL MAINTAIN HIGH-END
CHANCE POPS FOR THESE AREAS...BUT RAIN CHANCES WILL NEED TO BE
INCREASED IN FUTURE FORECASTS. AFTERNOON CONVECTION AND EASTERLY
FLOW WILL KEEP HIGHS GENERALLY IN THE 80S...EXCEPT NEAR 90 OVER
NORTH CENTRAL FL. INCREASING LOW-LEVEL MOISTURE WILL KEEP LOWS THURS
NIGHT IN THE UPPER 60S TO LOWER 70S. CONVERGENT LOW LEVEL FLOW OFF
THE ATLANTIC MAY DRIVE A FEW NOCTURNAL SHOWERS ONSHORE INTO THE
COASTAL COUNTIES...GENERALLY AFTER MIDNIGHT.
.LONG TERM (FRIDAY THROUGH MONDAY)... MID-LEVEL RIDGING WILL PREVAIL
OVER THE FL PENINSULA FRI AND SAT DOWNSTREAM OF TROUGHING ALOFT
EMERGING FROM THE ROCKIES AND MOVING NORTHEASTWARD TOWARDS THE GREAT
LAKES STATES. SOUTHEASTERLY LOW LEVEL FLOW WILL MAINTAIN A SCATTERED
TO NUMEROUS MAINLY AFTERNOON AND EVENING CONVECTIVE PATTERN FOR
INLAND LOCATIONS...WITH HIGHEST ACTIVITY EXPECTED ALONG THE I-75
CORRIDOR. A FEW COASTAL SHOWERS MAY AGAIN MOVE ONSHORE FRI NIGHT
INTO EARLY SAT EAST OF I-95. HIGHS WILL REMAIN NEAR TO SLIGHTLY
ABOVE AVERAGE...WITH 80S EXPECTED. ABOVE AVERAGE LOWS IN THE UPPER
60S TO LOWER 70S ARE FORECAST. DEEP-LAYERED RIDGING OVER THE WESTERN
ATLANTIC WILL BEGIN TO WEAKEN TOWARDS SUNDAY...WITH SOME DRIER AIR
ALOFT POSSIBLY MOVING INTO OUR REGION FROM THE EAST.
HOWEVER...INCREASING INSOLATION SHOULD KEEP SEA BREEZES ACTIVE
THROUGH EARLY NEXT WEEK...AND WE WILL MAINTAIN A SCATTERED DIURNAL
CONVECTIVE PATTERN IN THE FORECAST GRIDS. HIGHS WILL CLIMB BACK UP
TOWARDS 90 AT INLAND LOCATIONS...WITH SEA BREEZES KEEPING HIGHS AT
THE COAST IN THE 80S. ABOVE AVERAGE LOW TEMPERATURES WILL PREVAIL.
&&
.AVIATION...PREVAILING VFR. ISOLD CONVECTION WILL NEAR JAX...VQQ
AND GNV THIS AFTN AND EARLY EVENING AS THE ATLC SEA BREEZE PUSHES
INLAND REST OF THE AFTN. INCLUDED VICINITY WORDING FOR THESE TAFS. SE
WINDS 10-15 KT FOR THE COASTAL TAFS REST OF THE AFTN...BECOMING
LIGHT SLY BY LATE EVENING/OVERNIGHT. EXPECT MOST CONVECTION TO
DISSIPATE BY 00Z-03Z TONIGHT. MVFR VSBY POSSIBLE FOR VQQ FROM 07Z-
12Z. ANY ISOLD CONVECTION ON TUESDAY WILL LIKELY HOLD OFF UNTIL
AFTER 18Z.
&&
.MARINE...SLY WINDS AROUND 15 KT...POSSIBLY A BIT HIGHER AT TIMES
TONIGHT THROUGH TUESDAY. LATEST OBSERVED WINDS AND RAP MODEL SUGGEST
NEED FOR SCEC FOR THE NEAR SHORE WATERS THIS EVENING AND WILL
INCLUDE WITH THE AFTN CWF. SEAS MAINLY 2-4 FT...LOCALLY HIGHER AT
TIMES. A WEAK COLD FRONT WILL DROP SOUTHWARD ACROSS AREA WATERS
WEDNESDAY AFTERNOON AND OVERNIGHT WITH WINDS BECOMING ONSHORE AND
INCREASING THROUGH THURSDAY. AN EXERCISE CAUTION WILL LIKELY BE
NEEDED FOR THE OFFSHORE WATERS THURSDAY AND FRIDAY...WITH A CHANCE
OF SCA HEADLINE. THE FRONT WILL BECOME DIFFUSE S OF THE AREA BY
FRIDAY AND SATURDAY AND HIGH PRES N OF THE AREA WILL SHIFT OFFSHORE
INTO THE WRN ATLC VEERING LOCAL WINDS AROUND TO E AND SE.
RIP CURRENTS: MAINLY LOW RISK THROUGH TUESDAY DUE TO MINIMAL
SWELLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 66 92 69 89 / 20 20 20 20
SSI 71 86 70 82 / 10 10 20 20
JAX 68 91 70 88 / 10 20 10 30
SGJ 72 87 71 84 / 10 20 10 20
GNV 66 92 68 91 / 20 30 40 40
OCF 68 92 70 91 / 20 30 40 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/NELSON/WALSH
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
321 PM EDT MON MAY 11 2015
.DISCUSSION...
TONIGHT-TUE...AXIS OF LOW LEVEL SURFACE RIDGE ACROSS CENTRAL
FLORIDA WILL HOLD IN PLACE OR NUDGE SLIGHTLY TO THE NORTH. THIS
WILL CONTINUE A RATHER MOIST SOUTHEAST WIND FLOW IN THE LOWER
LEVELS. MID/UPPER LEVELS DO NOT APPEAR PARTICULARLY UNFAVORABLE
FOR CONVECTION AS WINDS ARE LIGHT AND SUBSIDENCE WEAK...BUT NO
IMPULSES WILL BE AFFECTING THE AREA AND THERE IS STILL PLENTY OF
DRY AIR THERE.
THROUGH TONIGHT...STILL EXPECT SCATTERED SHOWERS/STORMS ALONG THE
SEA BREEZE BOUNDARY ACROSS INTERIOR SECTIONS. GREATEST COVERAGE
SHOULD BE ACROSS LAKE COUNTY WHERE THE HRRR IS STILL SHOWING THE
INTERACTION OF THE EAST/WEST COAST SEA BREEZES. OTHERWISE...QUITE
MOIST ONSHORE FLOW MAY BLOW A FEW SHOWERS INTO THE SPACE/TREASURE
COAST OVERNIGHT. THE MOIST/MILD AIR MASS WILL KEEP MIN TEMPS IN
THE UPPER 60S TO LOWER 70S.
FOR TUE...PRECIPITABLE WATER VALUES ARE ONLY FORECAST TO START
OUT THE DAY BETWEEN 1.3 AND 1.5 INCHES AGAIN DUE TO THE LINGERING
DRY AIR ALOFT. THIS WILL CONTINUE TO KEEP POPS LIMITED WITH 20
PERCENT NEAR THE COAST AND 30 INLAND. GREATEST MOISTURE CONVERGENCE
AND CHANCE FOR STRONG STORMS WILL SHIFT TOWARDS THE WEST COAST
LATE IN THE DAY.
MAX TEMPS TYPICAL OF THE EARLY CONVECTIVE SEASON WILL CONTINUE
WITH MID/UPPER 80S ALONG THE COAST AND LOWER 90S INLAND.
WED-THU...WEAK FRONTAL BOUNDARY STALLS NORTH OF THE REGION MID WEEK
AS AN AREA OF HIGH PRESSURE BUILDS TOWARD THE MID ATLANTIC COAST.
THIS WILL INCREASE THE LOW LEVEL ONSHORE FLOW ACROSS THE REGION
THROUGH THE PERIOD. WEATHER PATTERN WILL FAVOR GREATEST CHANCE FOR
SHOWERS AND STORMS ACROSS THE INTERIOR AND WESTERN FL PENINSULA
ALONG THE EAST COAST SEA BREEZE. HIGHS WILL REACH THE LOW 90S ACROSS
THE INTERIOR WED AFT BUT FASTER INLAND MOVEMENT OF THE EAST COAST
SEA BREEZE THU LOOK TO LIMIT MAX TEMPS TO UPPER 80S/NEAR 90.
FRI-SUN...CENTER OF SURFACE HIGH PRESSURE OVER THE MID ATLANTIC
SHIFTS JUST OFFSHORE INTO THE WEEKEND WITH MODELS CONTINUING A
MODERATE EAST TO SOUTHEAST FLOW ACROSS THE REGION. LATE NIGHT AND
MORNING COASTAL SHOWERS WILL GIVE WAY TO ISOLATED TO SCATTERED
AFTERNOON CONVECTION ALONG THE SEA BREEZE AS IT MOVES INLAND AND
ENCOUNTERS MORE UNSTABLE MOIST AIR OVER THE INTERIOR. HIGHS NEAR TO
A COUPLE DEGREES ABOVE CLIMO IN THE MID-UPPER 80S.
&&
.AVIATION...
LARGELY VFR THROUGH THE PERIOD. THERE IS A SMALL CHANCE FOR STORMS
TO AFFECT NORTHERN TERMINALS THROUGH EVENING...PARTICULARLY KLEE.
ONSHORE FLOW MAY BRING A FEW SHOWERS TO THE COAST OVERNIGHT INTO
TUE MORNING...MAINLY KMLB-KSUA. HIGHEST CHANCE FOR AFTERNOON
SHOWERS/STORMS ON TUE WILL AGAIN BE ALONG/WEST OF I-4.
&&
.MARINE...
TONIGHT-TUE...LITTLE CHANGE WITH SURFACE RIDGE AXIS BRINGING A
SOUTHEAST WIND FLOW...WITH MORE OF A SOUTHERLY COMPONENT FAR
NORTH OVERNIGHT/EARLY TUE. SPEEDS SHOULD BE 10-15 KNOTS MOST AREAS
TONIGHT THEN WITH HIGH PRESSURE RIDGE STARTING TO WEAKEN SLIGHTLY
ON TUE...THE SPEEDS SHOULD EASE A FEW KNOTS. A SLIGHT CHANCE FOR
STORMS WILL EXIST TONIGHT INTO TUE MORNING...ESPECIALLY NEAR THE
GULF STREAM.
WED-SAT...HIGH PRESSURE RIDGE BUILDING TOWARD THE MID ATLANTIC WILL
INCREASE ONSHORE FLOW INTO LATE WEEK...UP TO 10-15 KNOTS. SEAS WILL
GRADUALLY RISE...INCREASING UP TO 5 FEET OFFSHORE BY FRI.
MODERATE ONSHORE BREEZE WILL CONTINUE INTO THE WEEKEND WITH SEAS UP
TO 5 TO 6 FEET POSSIBLE OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 70 88 70 88 / 10 20 10 20
MCO 71 93 71 92 / 20 30 10 30
MLB 73 87 73 86 / 10 20 10 20
VRB 71 86 71 86 / 20 20 20 20
LEE 73 93 73 92 / 30 30 20 40
SFB 71 92 71 91 / 20 20 10 30
ORL 72 92 73 91 / 20 20 10 30
FPR 71 87 71 86 / 20 20 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
LONG TERM....WEITLICH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
551 PM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 548 PM CDT MON MAY 11 2015
UPDATE FOR 00Z AVIATION ONLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 300 PM CDT MON MAY 11 2015
LEADING EDGE OF SURFACE COLD FRONTAL BOUNDARY EDGING INTO WESTERN
EDGE OF WFO PAH FORECAST AREA, STRETCHING FROM WEST OF
PINCKNEYVILLE IL, ONWARD TO PERRYVILLE AND VAN BUREN MISSOURI.
HIGH RESOLUTION GUIDANCE SUGGEST THAT LOW LEVEL CAPE FOR
CONVECTION WILL BE MINIMAL AFTER 4 PM ALONG THE EASTERN EDGE OF
THE PENNYRILE REGION OF WEST KENTUCKY. ANTICIPATE LITTLE IN THE
WAY OF WIDESPREAD AND SIGNIFICANT THUNDERSTORM ACTIVITY FOR THE
REMAINDER OF THIS FIRST PERIOD. THE HRRR GUIDANCE APPEARED TO HAVE
A GOOD HANDLE ON THE ISOLATED CONVECTION DEVELOPING AFTER 19Z OVER
THE CENTRAL PENNYRILE REGION OF WEST KENTUCKY.
BEYOND THIS AFTERNOON, HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
DOMINATE THE AREA UNTIL AFTER MIDNIGHT WEDNESDAY NIGHT WHEN THE
LEADING EDGE OF LIFT, INSTABILITY AND MOISTURE MOVE INTO SOUTHEAST
MISSOURI AND SOUTHWEST ILLINOIS AHEAD OF THE NEXT SHORTWAVE
STRENGTHENS OVER THE CENTRAL ROCKIES EARLY WEDNESDAY EVENING.
ADDED A SMALL CHANCE OF THUNDERSTORMS AND BLENDED INTERNALLY AND
EXTERNALLY WITH OTHER NWS OFFICES TO REFLECT SLOW EASTWARD
PROGRESSION BY DAYBREAK ON THURSDAY.
UTILIZED A BLEND OF GFS/NAM-WRF/ECWMF BLENDED GUIDANCE FOR
TEMPERATURES AND DEWPOINTS, WITH AN EMPHASIS TOWARD LAMP/NAM-WRF
FOR DEWPOINTS, WINDS, AND SKY COVER THROUGH TUESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 300 PM CDT MON MAY 11 2015
THE EXTENDED PERIOD WILL BEGIN WITH A MID LEVEL SHRTWV EJECTING
OUT OF THE SWRN CONUS AND MOVING INTO THE CENTRAL PLAINS AS MOIST
RETURN FLOW BEGINS TO GET ESTABLISHED THU. THE MED RANGE MODELS
HAVE A PRETTY CONSISTENT SIGNAL WITH THIS INITIAL PCPN
GENERATOR...HOWEVER SOME MODEL SOLUTIONS SUGGEST THAT...SIMILAR TO
WHAT HAS BEEN HAPPENING LATELY...MOST OF THE ENERGY MAY BE SHUNTED
NWD...LEAVING THE PAH FORECAST AREA WITH LIMITED PCPN CHANCES THU.
ON SAT...THE MODELS DEPICT ANOTHER SHALLOWER SHRTWV EMBEDDED IN
THE SWRLY FLOW TO MOVE THROUGH OUR REGION. THOUGH THE MED RANGE
MODELS/ENSEMBLES ARE IN GOOD GENERAL AGREEMENT ON THE LARGE SCALE
FEATURES...THE SMALLER DETAILS ARE MORE VAGUE. THUS THE TIMING OF
PCPN EVENTS IS APPROXIMATE. IN FACT...MOST OF THE FORECAST
CONTAINS 30% TO 50% POPS IN EACH 12 HOUR PERIOD...THOUGH THE MODEL
BLEND INITIALIZATION PROVIDED "LIKELIES" IN SOME CASES. ONE
EXCEPTION TO THE CONSTANT POPS IS SAT NIGHT...WHERE POPS ARE
MOSTLY SLIGHT IN THE WAKE OF THE SAT SYSTEM. THE PERSISTENT SRLY
LOW LEVEL FLOW AND SWRLY FLOW ALOFT WILL CERTAINLY BE CONDUCIVE TO
KEEPING THE MOISTURE LEVELS HIGH...TO BE ACTED ON BY ENERGY ALOFT.
BY EARLY MON...ANOTHER BUNDLE OF SHRTWV ENERGY IS PROGGED TO EJECT
OUT OF THE DOMINANT SWRN CONUS TROF...DRAGGING A SFC COLD FRONT TO
ITS SOUTH. THIS SHOULD REPRESENT A GOOD BET OF SHOWER AND TSTM
DEVELOPMENT FOR THE PAH FORECAST AREA. TIMING COULD CHANGE THIS FAR
OUT IN THE FORECAST HOWEVER.
EXPECT ABOVE AVERAGE TEMPS THROUGH THE EXTENDED PERIOD.
&&
.AVIATION...
ISSUED AT 548 PM CDT MON MAY 11 2015
CLEARING SKIES WILL RESULT IN VFR CONDITIONS THROUGH THE VALID
TIME OF ALL TAF SITES. WINDS WILL STAY UP OVERNIGHT WITHOUT THE
GUSTS AND BEGIN TO SHIFT FROM WEST TO NORTHWEST AND INCREASE
AFTER SUNRISE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...KH
SHORT TERM...SMITH
LONG TERM...DB
AVIATION...KH
AREA FORECAST DISCUSSION
NWS PADUCAH KY
301 PM CDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 300 PM CDT MON MAY 11 2015
LEADING EDGE OF SURFACE COLD FRONTAL BOUNDARY EDGING INTO WESTERN
EDGE OF WFO PAH FORECAST AREA, STRETCHING FROM WEST OF
PINCKNEYVILLE IL, ONWARD TO PERRYVILLE AND VAN BUREN MISSOURI.
HIGH RESOLUTION GUIDANCE SUGGEST THAT LOW LEVEL CAPE FOR
CONVECTION WILL BE MINIMAL AFTER 4 PM ALONG THE EASTERN EDGE OF
THE PENNYRILE REGION OF WEST KENTUCKY. ANTICIPATE LITTLE IN THE
WAY OF WIDESPREAD AND SIGNIFICANT THUNDERSTORM ACTIVITY FOR THE
REMAINDER OF THIS FIRST PERIOD. THE HRRR GUIDANCE APPEARED TO HAVE
A GOOD HANDLE ON THE ISOLATED CONVECTION DEVELOPING AFTER 19Z OVER
THE CENTRAL PENNYRILE REGION OF WEST KENTUCKY.
BEYOND THIS AFTERNOON, HIGH PRESSURE AT THE SURFACE AND ALOFT WILL
DOMINATE THE AREA UNTIL AFTER MIDNIGHT WEDNESDAY NIGHT WHEN THE
LEADING EDGE OF LIFT, INSTABILITY AND MOISTURE MOVE INTO SOUTHEAST
MISSOURI AND SOUTHWEST ILLINOIS AHEAD OF THE NEXT SHORTWAVE
STRENGTHENS OVER THE CENTRAL ROCKIES EARLY WEDNESDAY EVENING.
ADDED A SMALL CHANCE OF THUNDERSTORMS AND BLENDED INTERNALLY AND
EXTERNALLY WITH OTHER NWS OFFICES TO REFLECT SLOW EASTWARD
PROGRESSION BY DAYBREAK ON THURSDAY.
ULILIZED A BLEND OF GFS/NAM-WRF/ECWMF BLENDED GUIDANCE FOR
TEMPERATURES AND DEWPOINTS, WITH AN EMPHASIS TOWARD LAMP/NAM-WRF
FOR DEWPOINTS, WINDS, AND SKY COVER THROUGH TUESDAY.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 300 PM CDT MON MAY 11 2015
THE EXTENDED PERIOD WILL BEGIN WITH A MID LEVEL SHRTWV EJECTING
OUT OF THE SWRN CONUS AND MOVING INTO THE CENTRAL PLAINS AS MOIST
RETURN FLOW BEGINS TO GET ESTABLISHED THU. THE MED RANGE MODELS
HAVE A PRETTY CONSISTENT SIGNAL WITH THIS INITIAL PCPN
GENERATOR...HOWEVER SOME MODEL SOLUTIONS SUGGEST THAT...SIMILAR TO
WHAT HAS BEEN HAPPENING LATELY...MOST OF THE ENERGY MAY BE SHUNTED
NWD...LEAVING THE PAH FORECAST AREA WITH LIMITED PCPN CHANCES THU.
ON SAT...THE MODELS DEPICT ANOTHER SHALLOWER SHRTWV EMBEDDED IN
THE SWRLY FLOW TO MOVE THROUGH OUR REGION. THOUGH THE MED RANGE
MODELS/ENSEMBLES ARE IN GOOD GENERAL AGREEMENT ON THE LARGE SCALE
FEATURES...THE SMALLER DETAILS ARE MORE VAGUE. THUS THE TIMING OF
PCPN EVENTS IS APPROXIMATE. IN FACT...MOST OF THE FORECAST
CONTAINS 30% TO 50% POPS IN EACH 12 HOUR PERIOD...THOUGH THE MODEL
BLEND INITIALIZATION PROVIDED "LIKELIES" IN SOME CASES. ONE
EXCEPTION TO THE CONSTANT POPS IS SAT NIGHT...WHERE POPS ARE
MOSTLY SLIGHT IN THE WAKE OF THE SAT SYSTEM. THE PERSISTENT SRLY
LOW LEVEL FLOW AND SWRLY FLOW ALOFT WILL CERTAINLY BE CONDUCIVE TO
KEEPING THE MOISTURE LEVELS HIGH...TO BE ACTED ON BY ENERGY ALOFT.
BY EARLY MON...ANOTHER BUNDLE OF SHRTWV ENERGY IS PROGGED TO EJECT
OUT OF THE DOMINANT SWRN CONUS TROF...DRAGGING A SFC COLD FRONT TO
ITS SOUTH. THIS SHOULD REPRESENT A GOOD BET OF SHOWER AND TSTM
DEVELOPMENT FOR THE PAH FORECAST AREA. TIMING COULD CHANGE THIS FAR
OUT IN THE FORECAST HOWEVER.
EXPECT ABOVE AVERAGE TEMPS THROUGH THE EXTENDED PERIOD.
&&
.AVIATION...
ISSUED AT 100 PM CDT MON MAY 11 2015
THE MAIN STORY IN THE TAFS IS THE WIND...WHICH SHOULD GUST AOA 20
KTS THIS AFTERNOON...ESPECIALLY IN THE ERN HALF OF THE REGION
(INCLUDING KEVV/KOWB). THIS IS ASSOCIATED WITH A WEST TO EAST COLD
FRONTAL PASSAGE. SHOWERS MAY AFFECT THE ERN TAFS THIS AFTERNOON...
BUT WITH A RATHER STABLE ATMOSPHERE IN PLACE AND AMPLE CLOUD
COVER...A TSTM DID NOT SEEM LIKELY ENOUGH TO INCLUDE IN ANY TAFS AT
THIS TIME. MVFR CIGS SHOULD BE COMMON ESPECIALLY IN THE WRN HALF OF
THE REGION BEFORE CLEARING AROUND SUNSET. AFTER SUBSIDING SOME
OVERNIGHT...WINDS SHOULD PICK UP AGAIN TUE WITH A MORE WRLY
COMPONENT.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...DB
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
314 PM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 311 PM EDT MON MAY 11 2015
UPDATED GRIDS TO ADD ENHANCED WORDING AND INCLUDE THE WATCH IN THE
ZONE PRODUCT. OTHERWISE QUICK FRESHENING UP OF THE GRIDS FOR
LATEST OBS AND TRENDS.
UPDATE ISSUED AT 150 PM EDT MON MAY 11 2015
DID A QUICK UPDATE TO FRESHEN UP THE GRID WITH THE LATEST OBS AND
TRENDS. UNDER MODERATELY UNSTABLE ENVIRONMENT AND CONVECTIVE
TEMPS REACHED...WE HAVE SEEN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS FIRE UP ACROSS EASTERN KY. HOWEVER GIVEN WEAKER
SUPPORT MOST OF THE ACTIVITY HAS BEEN FAIRLY DISORGANIZED. THE
MORE ORGANIZED CONVECTION IS OCCURRING ACROSS THE SW PORTIONS OF
THE CWA THIS AFTERNOON. THE MAIN THREAT FROM THESE STORMS WILL BE
ISOLATED SEVERE WINDS AND HEAVY DOWNPOURS.
UPDATE ISSUED AT 1050 AM EDT MON MAY 11 2015
YET ANOTHER WARM DAY IS ON TAP FOR EASTERN KENTUCKY. THE BIGGEST
QUESTION FOR TODAY WILL BE WHEN AND IF CONVECTION FIRES AHEAD OF A
BOUNDARY INCHING TOWARD THE MISSISSIPPI RIVER BASED ON THE 12Z
SURFACE ANALYSIS. EARLIER RUNS OF THE HRRR HAD A MORE PRONOUNCED
AREA OF CONVECTION AHEAD OF THE MAIN OUTFLOW DRAPED TO THE WEST.
THE MORE RECENT RUNS HAVE BACK OFF ON THIS NOTION...HOWEVER STILL
BRING AREA OF CONVECTION OUT OF THE TN VALLEY AFTER 18Z. ONE OF
THE ISSUES WILL BE LACK OF SHEAR AHEAD OF THE MAIN UPPER LEVEL
SYSTEM AND LIFTING MECHANISMS. THE SPC HAS DOWNGRADED MOST OF
EASTERN KY TO A MARGINAL RISK FOR THE TODAY. THIS SEEMS REASONABLE
GIVEN THE CURRENT FORECAST ISSUES/CONFIDENCE HEADING INTO THIS
AFTERNOON. GIVEN THE UNCERTAINTY THAT REMAINS ISOLATED DAMAGING
WIND TREAT SEEMS REASONABLE AT THIS POINT...SO WILL KEEP THAT IN
THE HWO. OTHERWISE DID UPDATED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON MAY 11 2015
THIS AFTERNOON WE HAVE SEEN CONVECTION FIRE UP ACROSS PORTIONS OF
EASTERN KY. THESE ISOLATED TO SCATTER STORMS WILL BE THE BIGGEST
CONCERN FOR THE NEXT FEW HOURS. IT DOES LOOK LIKE THERE COULD BE
TWO ROUND...ONE ONGOING CONVECTION MORE DIURNALLY DRIVEN UNDER
MODERATELY UNSTABLE ENVIRONMENT...TWO THE COLD FRONT AND ANY
OUTFLOWS AHEAD OF THE FRONT. THE SECOND LINE IS IN QUESTION GIVEN
THAT STORMS HAVE ALREADY FIRED AND COULD TAP OUT THE CURRENT
UNSTABLE ENVIRONMENT. THE BIGGEST THREAT FROM THIS AVIATION WISE
LOOKS TO BE THE POTENTIAL FOR GUSTY WINDS AND REDUCED VIS.
OTHERWISE OVERNIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIE
OFF WITH DAYTIME HEATING AND FRONT SWEEPING ACROSS THE REGION.
THE OTHER ISSUE TONIGHT WILL BE POTENTIAL FOR FOG AND/OR LOW
STRATUS DECK. RIGHT NOW PLAN TO KEEP LOW STRATUS DECK WITH
POTENTIAL FOR AT LEAST MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY. HIGH PRESSURE WILL RETURN TOMORROW WITH CLEARING SKIES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
100 PM CDT MON MAY 11 2015
UPDATE...
ISSUED AT 100 PM MON MAY 11 2015 UPDATED AVIATION SECTION ONLY.
&&
UPDATE...
ISSUED AT 1200 PM CDT MON MAY 11 2015
QUICK UPDATE TO REFLECT SHORT TERM TRENDS THIS AFTERNOON WITH
RESPECT TO CONVECTIVE ACTIVITY AND SENSIBLE WEATHER ELEMENTS. ANY
LOCALIZED BREAKS IN THE CLOUD COVER MAY CAUSE SLIGHT ELEVATION IN
TEMPERATURES BY 1-3 DEGREES ABOVE CURRENT FORECAST.
ANTICIPATE MOST OF THE CONVECTION THIS AFTERNOON MAY REMAIN
SOMEWHAT ELEVATED WITH THE APPROACHING FRONT, THE FRONTAL LOCATION
SUGGESTED BY THE FINE LINE ON THE KLSX RADAR ALONG AND EAST OF
THE MISSISSIPPI RIVER. SPC MARGINAL RISK FOR SEVERE STORMS SEEMS
SOMEWHAT OPTIMISTIC, BUT THE POTENTIAL FOR SOME SURFACE-BASED
CONVECTION WILL STILL REMAIN POSSIBLE OVER THE EASTERN PARTS OF
SOUTHWEST INDIANA AND THE PENNYRILE REGION OF WEST KENTUCKY
BETWEEN NOON AND 5 PM.
ISSUED A SPECIAL WEATHER STATEMENT FOR GUSTY WINDS AHEAD OF THE
FRONT IN SOUTHWEST INDIANA AND WEST KENTUCKY OUTSIDE OF CONVECTION
THIS AFTERNOON...MAINLY FOR BOATERS AND TRAVELERS ON THE ROAD.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 100 PM CDT MON MAY 11 2015
THE MAIN STORY IN THE TAFS IS THE WIND...WHICH SHOULD GUST AOA 20
KTS THIS AFTERNOON...ESPECIALLY IN THE ERN HALF OF THE REGION
(INCLUDING KEVV/KOWB). THIS IS ASSOCIATED WITH A WEST TO EAST COLD
FRONTAL PASSAGE. SHOWERS MAY AFFECT THE ERN TAFS THIS AFTERNOON...
BUT WITH A RATHER STABLE ATMOSPHERE IN PLACE AND AMPLE CLOUD
COVER...A TSTM DID NOT SEEM LIKELY ENOUGH TO INCLUDE IN ANY TAFS AT
THIS TIME. MVFR CIGS SHOULD BE COMMON ESPECIALLY IN THE WRN HALF OF
THE REGION BEFORE CLEARING AROUND SUNSET. AFTER SUBSIDING SOME
OVERNIGHT...WINDS SHOULD PICK UP AGAIN TUE WITH A MORE WRLY
COMPONENT.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...DRS
LONG TERM...RJP
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 PM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 150 PM EDT MON MAY 11 2015
DID A QUICK UPDATE TO FRESHEN UP THE GRID WITH THE LATEST OBS AND
TRENDS. UNDER MODERATELY UNSTABLE ENVIRONMENT AND CONVECTIVE
TEMPS REACHED...WE HAVE SEEN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS FIRE UP ACROSS EASTERN KY. HOWEVER GIVEN WEAKER
SUPPORT MOST OF THE ACTIVITY HAS BEEN FAIRLY DISORGANIZED. THE
MORE ORGANIZED CONVECTION IS OCCURRING ACROSS THE SW PORTIONS OF
THE CWA THIS AFTERNOON. THE MAIN THREAT FROM THESE STORMS WILL BE
ISOLATED SEVERE WINDS AND HEAVY DOWNPOURS.
UPDATE ISSUED AT 1050 AM EDT MON MAY 11 2015
YET ANOTHER WARM DAY IS ON TAP FOR EASTERN KENTUCKY. THE BIGGEST
QUESTION FOR TODAY WILL BE WHEN AND IF CONVECTION FIRES AHEAD OF A
BOUNDARY INCHING TOWARD THE MISSISSIPPI RIVER BASED ON THE 12Z
SURFACE ANALYSIS. EARLIER RUNS OF THE HRRR HAD A MORE PRONOUNCED
AREA OF CONVECTION AHEAD OF THE MAIN OUTFLOW DRAPED TO THE WEST.
THE MORE RECENT RUNS HAVE BACK OFF ON THIS NOTION...HOWEVER STILL
BRING AREA OF CONVECTION OUT OF THE TN VALLEY AFTER 18Z. ONE OF
THE ISSUES WILL BE LACK OF SHEAR AHEAD OF THE MAIN UPPER LEVEL
SYSTEM AND LIFTING MECHANISMS. THE SPC HAS DOWNGRADED MOST OF
EASTERN KY TO A MARGINAL RISK FOR THE TODAY. THIS SEEMS REASONABLE
GIVEN THE CURRENT FORECAST ISSUES/CONFIDENCE HEADING INTO THIS
AFTERNOON. GIVEN THE UNCERTAINTY THAT REMAINS ISOLATED DAMAGING
WIND TREAT SEEMS REASONABLE AT THIS POINT...SO WILL KEEP THAT IN
THE HWO. OTHERWISE DID UPDATED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON MAY 11 2015
THIS AFTERNOON WE HAVE SEEN CONVECTION FIRE UP ACROSS PORTIONS OF
EASTERN KY. THESE ISOLATED TO SCATTER STORMS WILL BE THE BIGGEST
CONCERN FOR THE NEXT FEW HOURS. IT DOES LOOK LIKE THERE COULD BE
TWO ROUND...ONE ONGOING CONVECTION MORE DIURNALLY DRIVEN UNDER
MODERATELY UNSTABLE ENVIRONMENT...TWO THE COLD FRONT AND ANY
OUTFLOWS AHEAD OF THE FRONT. THE SECOND LINE IS IN QUESTION GIVEN
THAT STORMS HAVE ALREADY FIRED AND COULD TAP OUT THE CURRENT
UNSTABLE ENVIRONMENT. THE BIGGEST THREAT FROM THIS AVIATION WISE
LOOKS TO BE THE POTENTIAL FOR GUSTY WINDS AND REDUCED VIS.
OTHERWISE OVERNIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIE
OFF WITH DAYTIME HEATING AND FRONT SWEEPING ACROSS THE REGION.
THE OTHER ISSUE TONIGHT WILL BE POTENTIAL FOR FOG AND/OR LOW
STRATUS DECK. RIGHT NOW PLAN TO KEEP LOW STRATUS DECK WITH
POTENTIAL FOR AT LEAST MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY. HIGH PRESSURE WILL RETURN TOMORROW WITH CLEARING SKIES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
136 PM EDT MON MAY 11 2015
.UPDATE...
ISSUED AT 1050 AM EDT MON MAY 11 2015
YET ANOTHER WARM DAY IS ON TAP FOR EASTERN KENTUCKY. THE BIGGEST
QUESTION FOR TODAY WILL BE WHEN AND IF CONVECTION FIRES AHEAD OF A
BOUNDARY INCHING TOWARD THE MISSISSIPPI RIVER BASED ON THE 12Z
SURFACE ANALYSIS. EARLIER RUNS OF THE HRRR HAD A MORE PRONOUNCED
AREA OF CONVECTION AHEAD OF THE MAIN OUTFLOW DRAPED TO THE WEST.
THE MORE RECENT RUNS HAVE BACK OFF ON THIS NOTION...HOWEVER STILL
BRING AREA OF CONVECTION OUT OF THE TN VALLEY AFTER 18Z. ONE OF
THE ISSUES WILL BE LACK OF SHEAR AHEAD OF THE MAIN UPPER LEVEL
SYSTEM AND LIFTING MECHANISMS. THE SPC HAS DOWNGRADED MOST OF
EASTERN KY TO A MARGINAL RISK FOR THE TODAY. THIS SEEMS REASONABLE
GIVEN THE CURRENT FORECAST ISSUES/CONFIDENCE HEADING INTO THIS
AFTERNOON. GIVEN THE UNCERTAINTY THAT REMAINS ISOLATED DAMAGING
WIND TREAT SEEMS REASONABLE AT THIS POINT...SO WILL KEEP THAT IN
THE HWO. OTHERWISE DID UPDATED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 642 AM EDT MON MAY 11 2015
UPDATED FORECAST TO REFINE THE POPS THROUGH THE DAY INCLUDING THIS
EVENING. LAST 3 RUNS OF BOTH THE HRRR AND RAP HAVE SHOWN
CONVECTIVE INITIATION ALONG THE PREFRONTAL TROUGH BETWEEN 16Z AND
18Z. ALSO BASED ON THE LOCATION...ACTIVITY LOOKS TO BLOW UP OVER
EASTERN KENTUCKY THIS AFTERNOON BEFORE ADVANCING EAST INTO THE
EARLY EVENING HOURS. WITH THESE NEW TRENDS SUPPORTED BY SEVERAL
RUNS OF THE HI RES MODELS...HAVE OPTED TO PUT THE HIGHEST POPS
BETWEEN 17Z AND 23Z THIS AFTERNOON AND EARLY EVENING. GIVEN THE
EARLIER CONVECTION...WOULD NOT EXPECT MUCH TO SPREAD ACROSS THE
AREA AFTER 00Z TONIGHT GIVEN THE ATMOSPHERE WILL BE WORKED OVER
AND THUS...LITTLE TO NO INSTABILITY TO WORK WITH. THUS...HAVE
TRIMMED BACK POPS CONSIDERABLY FOR THE TONIGHT PORTION OF THE
FORECAST. STILL APPEARS THE MAIN THREAT WITH STORMS WILL BE
DAMAGING WINDS...BUT SOME HAIL COULD ALSO OCCUR. DUE TO THE
UNIDIRECTIONAL FLOW FROM SURFACE TO 700MB...WOULD NOT EXPECT MUCH
OF A TORNADO THREAT TODAY. GIVEN THE CHANGE IN POPS...ALSO
ADJUSTED CLOUD COVER AND TEMPERATURES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
UPPER LEVEL RIDGING REMAINS OVER THE EASTERN CONUS THIS MORNING
WITH TROPICAL DEPRESSION ANA MOVING NORTH ACROSS EASTERN NORTH
CAROLINA. CONVECTION OVERNIGHT ACROSS WESTERN KENTUCKY SENT A GUST
FRONT TO THE EAST WHERE IT CURRENTLY RESIDES FROM NEAR
FLEMINGSBURG...SOUTH TO SOMERSET. HOW THIS BOUNDARY MIGHT IMPACT
LATER CONVECTION IS STILL TO BE DETERMINED. ONLY SHOWERS AND
STORMS TO EVEN COME CLOSE TO THE AREA OVERNIGHT HAVE BEEN OVER
WEST VIRGINIA...FUELED BY OUTFLOW FROM STORMS YESTERDAY EVENING.
A SHORTWAVE TROUGH CONTINUES TO GENERATE ROUNDS OF SHOWERS AND
STORMS OVER THE SOUTHERN MISSISSIPPI RIVER VALLEY THIS MORNING.
THIS SHORTWAVE TROUGH WILL LIFT NORTHEAST TODAY INTO TONIGHT...
GENERATING MORE SHOWERS AND STORMS ACROSS THE OHIO RIVER VALLEY BY
THIS AFTERNOON/EVENING. BEST FORCING AND LIFT WILL RESIDE TO OUR
NORTH AND NORTHWEST THROUGH THE DAY AND EVEN TONIGHT. THIS WILL
LEAVE EASTERN KENTUCKY IN A VERY SIMILAR PATTERN THE PAST SEVERAL
DAYS WITH THE THREAT OF ISOLATED SHOWERS AND STORMS. IF THE
OUTFLOW BOUNDARY STALLS OVER THE AREA THIS MORNING...THIS MAY
SERVE AS THE FOCUS FOR SHOWERS AND STORMS TO DEVELOP LATER THIS
AFTERNOON WITH PEAK HEATING. WITH THE SHORTWAVE TROUGH FINALLY ON
THE MOVE INTO THE GREAT LAKES...A COLD FRONT WILL PUSH EAST WITH
THE GRADIENT TIGHTENING UP OVER THE AREA. THIS WILL YIELD
INCREASING WIND SHEAR AS WE HEAD THROUGH THE DAY. THUS...ANY
SHOWERS OR STORMS THAT DO MANAGE TO POP UP THIS AFTERNOON OR
EVENING WOULD HAVE THE POTENTIAL TO BECOME SEVERE. FLOW IS FAIRLY
UNIDIRECTIONAL...SO MAIN THREATS WOULD BE STRAIGHT LINE WINDS.
HAIL THREAT MAY BE THERE TOO IF INSTABILITY CAN BUILD ENOUGH PRIOR
TO STORM INITIATION...BUT FREEZING LEVELS ARE UP NEAR 12KFT
AGL...SO IT WILL TAKE SOME HEFTY UPDRAFTS TO GENERATE HAIL TODAY.
GIVEN THE SEVERE THREAT...THE AREA HAS BEEN PLACED IN A SLIGHT
RISK AREA FOR SEVERE THUNDERSTORMS BY THE SEVERE STORMS PREDICTION
CENTER.
THERE IS SOME WEAK FORCING THAT WILL PUSH ACROSS THE AREA
THIS EVENING AND HENCE THE BEST OPPORTUNITY FOR BETTER COVERAGE IN
SHOWERS AND STORMS. HOWEVER...LATEST HI-RES MODELS DO NOT SHOW
MUCH MOVING INTO THE AREA THIS EVENING...SO CONFIDENCE IS FAIRLY
LOW ON CONVECTION THIS EVENING AS OF RIGHT NOW. THUS...WILL STAY
WITH THE CHANCE POPS WITH THE PREVIOUS FORECAST. IF CONVECTION
FORMS...IT SHOULD BE ON THE WAY OUT BY MIDNIGHT...WITH SUBSIDENCE
BUILDING BEHIND THE DEPARTING STORMS. THE COLD FRONT WILL LAG WELL
BEHIND THE CONVECTION AND WILL NOT MAKE ITS MOVE ACROSS THE AREA
UNTIL TUESDAY MORNING...WHEN ANOTHER ISOLATED SHOWER MAY BE
POSSIBLE. IF THE FRONT HANGS UP TOO MUCH ON TUESDAY...MAY NEED TO
WATCH POTENTIAL FOR A FEW STORMS TO FIRE UP ON THE BOUNDARY AS IT
SLIPS ACROSS THE AREA. AS IT STANDS NOW...IT SHOULD MOVE THROUGH
IN TIME TO PREVENT THIS FROM HAPPENING. TUESDAY WILL BE COOLER
WITH DRIER AIR ADVECTING INTO THE AREA...THIS WILL MAKE FOR A
PLEASANT AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 342 AM EDT MON MAY 11 2015
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY NIGHT WITH UPPER
LEVEL RIDGING OVER THE REGION KEEPING EASTERN KENTUCKY DRY THROUGH
THE WEDNESDAY AND MUCH OF THURSDAY TIME PERIOD. THIS PATTERN SEEMS
TO TAKE A CHANGE AS THE PATTERN BECOMES MORE ACTIVE AND A STRONG
SHORTWAVE MOVES OUT OF THE SOUTHWESTERN CONUS AND TRAVELS OVER THE
RIDGE AND INTO THE UPPER PLAINS AND GREAT LAKES BY FRIDAY. THIS NOT
ONLY BRINGS SOME UPPER LEVEL SUPPORT INTO THE OH VALLEYS REGION BUT
ALSO OPENS THE GULF AS SOME MID LEVEL MOISTURE ADVECTS INTO THE
REGION. ALSO DURING THIS TIME ON FRIDAY...A STRONG CLOSED LOW COMES
ASHORE IN SOUTHERN CA. THIS FEATURE STANDS TO BRING A GOOD SHOT OF
UPPER LEVEL ENERGY TO THE PLAINS AND EVEN INTO THE MIDWEST BY
SUNDAY. THE EURO AND GFS ARE SIMILAR IN THIS TREND.
CLOSER TO THE SURFACE...THE APPROACH OF THE FIRST MENTIONED
SHORTWAVE WILL BRING INCREASED SOUTHERLY LOW LEVEL FLOW INTO THE
AREA AND AS THE RIDGE WEAKENS...CONVECTION WILL BECOME MORE AND MORE
PREVALENT...ESPECIALLY BY FRIDAY. A BOUNDARY SHOULD BEGIN TO FORM
TO THE NORTH OF THE OH RIVER WITH PLENTY OF CONVECTION BY FRIDAY
AFTERNOON AND AS WELL INTO THE WEEKEND. THIS LEAVES EASTERN
KENTUCKY IN A WARM...HUMID...AND UNSTABLE PATTERN WITH DIURNALLY
DRIVEN CONVECTION. BY SUNDAY HOWEVER...THE MENTIONED STRONG LOW
THAT CAME ASHORE OVER SOCA WILL MOVE INTO THE UPPER MIDWEST
DRAGGING A POTENT COLD FRONT TO THE OH VALLEY DOORSTEP.
THE EURO AND GFS DO SHOW SOME CONSISTENCY HERE. THE SUPER BLEND DID
COME IN RATHER HIGH IN POPS...ESPECIALLY FOR FRIDAY. TRENDS OF THE
RIDGE MIGHT BE ENOUGH TO SUPPRESS CONVECTION ENOUGH THAT LIKELY POPS
SEEM A BIT...UNLIKELY...AND SO LOWERED THEM DURING THIS TIME FRAME
AS WELL. ALSO THE BLEND HAD NO INDICATION OF ANY SORT OF DIURNALLY
TREND TO THE CONVECTION AND GIVEN WHAT THE AREA HAS EXPERIENCED THIS
PAST WEEK...THIS SEEMS TO BE A REPEAT OF SORTS. DID THEN ADDRESS
THIS WITH THE NEIGHBORING OFFICES AND MADE THESE ADJUSTMENTS TO THE
POPS INHERITED BY THE SUPER BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 133 PM EDT MON MAY 11 2015
THIS AFTERNOON WE HAVE SEEN CONVECTION FIRE UP ACROSS PORTIONS OF
EASTERN KY. THESE ISOLATED TO SCATTER STORMS WILL BE THE BIGGEST
CONCERN FOR THE NEXT FEW HOURS. IT DOES LOOK LIKE THERE COULD BE
TWO ROUND...ONE ONGOING CONVECTION MORE DIURNALLY DRIVEN UNDER
MODERATELY UNSTABLE ENVIRONMENT...TWO THE COLD FRONT AND ANY
OUTFLOWS AHEAD OF THE FRONT. THE SECOND LINE IS IN QUESTION GIVEN
THAT STORMS HAVE ALREADY FIRED AND COULD TAP OUT THE CURRENT
UNSTABLE ENVIRONMENT. THE BIGGEST THREAT FROM THIS AVIATION WISE
LOOKS TO BE THE POTENTIAL FOR GUSTY WINDS AND REDUCED VIS.
OTHERWISE OVERNIGHT SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIE
OFF WITH DAYTIME HEATING AND FRONT SWEEPING ACROSS THE REGION.
THE OTHER ISSUE TONIGHT WILL BE POTENTIAL FOR FOG AND/OR LOW
STRATUS DECK. RIGHT NOW PLAN TO KEEP LOW STRATUS DECK WITH
POTENTIAL FOR AT LEAST MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY. HIGH PRESSURE WILL RETURN TOMORROW WITH CLEARING SKIES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1203 PM CDT MON MAY 11 2015
.UPDATE...
ISSUED AT 1200 PM CDT MON MAY 11 2015
QUICK UPDATE TO REFLECT SHORT TERM TRENDS THIS AFTERNOON WITH
RESPECT TO CONVECTIVE ACTIVITY AND SENSIBLE WEATHER ELEMENTS. ANY
LOCALIZED BREAKS IN THE CLOUD COVER MAY CAUSE SLIGHT ELEVATION IN
TEMPERATURES BY 1-3 DEGREES ABOVE CURRENT FORECAST.
ANTICIPATE MOST OF THE CONVECTION THIS AFTERNOON MAY REMAIN
SOMEWHAT ELEVATED WITH THE APPROACHING FRONT, THE FRONTAL LOCATION
SUGGESTED BY THE FINE LINE ON THE KLSX RADAR ALONG AND EAST OF
THE MISSISSIPPI RIVER. SPC MARGINAL RISK FOR SEVERE STORMS SEEMS
SOMEWHAT OPTIMISTIC, BUT THE POTENTIAL FOR SOME SURFACE-BASED
CONVECTION WILL STILL REMAIN POSSIBLE OVER THE EASTERN PARTS OF
SOUTHWEST INDIANA AND THE PENNYRILE REGION OF WEST KENTUCKY
BETWEEN NOON AND 5 PM.
ISSUED A SPECIAL WEATHER STATEMENT FOR GUSTY WINDS AHEAD OF THE
FRONT IN SOUTHWEST INDIANA AND WEST KENTUCKY OUTSIDE OF CONVECTION
THIS AFTERNOON...MAINLY FOR BOATERS AND TRAVELERS ON THE ROAD.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 AM CDT MON MAY 11 2015
THE LARGE AREA OF CONVECTION THAT HAS BEEN ADVERTISED FOR
DAYS...HAS DEVELOPED RIGHT ON SCHEDULE EARLY THIS MORNING ACROSS
SOUTHEAST MISSOURI. THE PREPONDERANCE OF SHORT TERM GUIDANCE LIFTS
THE BAND NORTH NORTHEAST THROUGH SOUTHEAST MISSOURI AND SOUTHERN
ILLINOIS THROUGH THE MORNING HOURS...WITH THE TAIL END OF IT
DISSIPATING AS IT MOVES EAST THROUGH WEST KENTUCKY AND SOUTHWEST
INDIANA. THIS LARGE AREA OF CONVECTION SEEMS TO BE ASSOCIATED
WITH AN UPPER-LEVEL JET LIFTING NORTHWARD OUT OF THE AREA BY THIS
AFTERNOON.
THE BIG QUESTION IS WHAT WILL HAPPEN THIS AFTERNOON OVER WEST
KENTUCKY AND SOUTHWEST INDIANA. IT LOOKS LIKE SCATTERED CONVECTION
AT BEST...AS THE 06Z HRRR HAS NEXT TO NOTHING LEFT IN THE EAST
AFTER 17Z. THE POPS WITH THIS FORECAST PACKAGE ARE LIKELY TOO
WET IN THE EAST THIS AFTERNOON.
AS FOR SEVERE...WILL KEEP AN EYE ON RADAR THROUGH DAYBREAK...BUT
IT APPEARS THAT THERE ARE JUST TOO MANY UPDRAFTS FOR ANY ONE OF
THEM TO GET CLOSE TO SEVERE LEVELS. HAVE NOT SEEN ANYTHING SO FAR
THAT WAS ORIENTED IN SUCH A WAY AS TO CATCH THE ENVIRONMENTAL
WINDS...AND NOT SURE IF THE STRONGER WINDS WOULD REACH THE GROUND
GIVEN THE ELEVATED NATURE OF THE STORMS.
ANY STORM THAT GETS GOING IN THE EAST THIS AFTERNOON WOULD HAVE
SOME POTENTIAL TO BE SEVERE...BUT WIND FIELDS ARE STILL A BIT
SUSPECT...WITH MODEL SOUNDINGS INDICATING BACKING WINDS WITH
HEIGHT IN THE LOW-LEVELS. OF COURSE...WITH THE POTENTIAL FOR
CONVECTIVE DEVELOPMENT IN DOUBT THIS AFTERNOON...THE SEVERE
PROBABILITIES ARE RATHER LOW. BETTER CHANCES FOR SEVERE WOULD
SEEM TO BE EAST AND NORTHEAST OF OUR AREA.
IT STILL LOOKS LIKE THE CONVECTION WILL BE WELL EAST OF THE AREA
BY 00Z TUESDAY...AND THE REMAINDER OF THE SHORT TERM WILL BE
DRY WITH SURFACE HIGH PRESSURE DOMINATING THE REGION. CONSIDERED
INSERTING A SLIGHT CHANCE POP WEDNESDAY NIGHT IN THE FAR
WEST...BUT A GFS SOUNDING FROM THAT AREA WAS UNINSPIRING.
SOUTHWEST WINDS FROM MID-MORNING THROUGH MID AFTERNOON ARE
FORECAST TO BE AT OR ABOVE LAKE WIND ADVISORY CRITERIA OVER THE
EASTERN HALF OF THE AREA. HOWEVER...CONFIDENCE IN THE CONVECTIVE
EVOLUTION CASTS SOME DOUBT ON THE WIND FORECAST...SO WILL NOT
ISSUE AN ADVISORY AT THIS TIME. WILL LET THE DAY SHIFT MONITOR
TRENDS THIS MORNING AND ISSUE IF/WHEN IT BECOMES MORE OBVIOUS.
WEST NORTHWEST WINDS OVER THE NORTHERN HALF OF THE AREA WILL BE
NEAR CRITERIA ON TUESDAY AS WELL.
GENERALLY STAYED CLOSE TO THE CONSENSUS OF GUIDANCE FOR TEMPERATURES
THROUGH THE PERIOD. MAY NOT BE COLD ENOUGH TUESDAY NIGHT...WITH
DECENT RADIATIONAL COOLING REGIME AND DRY AIR IN PLACE.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON MAY 11 2015
ON THE LARGER SCALE...OPERATIONAL MODELS AND THEIR ENSEMBLES ARE IN
RELATIVELY GOOD AGREEMENT THROUGH THE EXTENDED PERIOD. HOWEVER...
MUCH OF THE WEATHER DURING THIS TIME WILL BE DRIVEN BY SUBTLE
MESOSCALE FEATURES THAT RESULT IN RELATIVELY WEAK FORCING. AS A
RESULT...OUR CONFIDENCE IS ONLY AVERAGE AT BEST DURING THIS TIME.
THE UPPER LEVEL PATTERN THROUGH THE WEEKEND WILL BE DOMINATED BY A
RIDGE POSITIONED FROM THE GULF COAST NORTHWARD ACROSS THE EASTERN
HALF OF THE NATION. A LARGE UPPER LEVEL LOW OVER THE EASTERN PACIFIC
IS FORECAST TO SLOWLY MIGRATE EAST INTO THE INTERMOUNTAIN WEST LATE
IN THE WEEK...REACHING THE PLAINS LATE IN THE WEEKEND.
AS FOR THE DETAILS...HIGH PRESSURE WILL SHIFT EAST OF THE REGION BY
THURSDAY. AN UPPER LEVEL DISTURBANCE IS FORECAST TO TRACK ACROSS THE
MIDDLE AND UPPER MISSISSIPPI RIVER VALLEYS AS A WARM FRONT LIFTS
NORTH ACROSS THE REGION THURSDAY AND THURSDAY NIGHT. THE RESULTANT
INCREASE IN MOISTURE AND INSTABILITY WILL LEAD TO OUR NEXT CHANCE OF
SHOWERS AND THUNDERSTORMS DURING THIS TIME.
BY FRIDAY AND SATURDAY...THE UPPER LEVEL RIDGE BECOMES THE DOMINANT
WEATHER FEATURE. HOWEVER...RATHER WARM AND HUMID CONDITIONS WILL
PREVAIL BENEATH THIS RIDGE. EVEN THOUGH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS CERTAINLY CANNOT BE RULED OUT...FORECAST
MODELS APPEAR TO BE OVERDONE WITH RESPECT TO PRECIPITATION CHANCES
AND COVERAGE. AS A RESULT...WE COLLABORATED WITH SURROUNDING OFFICES
TO REDUCE RAIN CHANCES TO NO HIGHER THAN 30-40 PERCENT DURING THIS
TIME. RAIN CHANCES SHOULD INCREASE LATE IN THE WEEKEND AS THE
REMNANTS OF THE UPPER LOW DRAW CLOSER.
TEMPERATURES WILL UNDERGO A SLOW WARMING TREND THROUGH THE PERIOD.
HIGHS WILL START OFF IN THE MID TO UPPER 70S ON THURSDAY...THEN
MODERATE INTO THE LOWER AND PERHAPS MID 80S BY THE WEEKEND. LOWS OF
50 TO 55 THURSDAY MORNING WILL RISE INTO THE LOWER AND MID 60S
DURING THE REMAINDER OF THE PERIOD.
&&
.AVIATION...
ISSUED AT 653 AM CDT MON MAY 11 2015
BAND OF RAIN AND EMBEDDED THUNDERSTORMS IS EXPECTED TO DISSIPATE
OR BECOME MORE SCATTERED AS IT MOVES SLOWLY EAST THROUGH 18Z. A
PERIOD OF MVFR CONDITIONS IS POSSIBLE AS THE PRECIPITATION MOVES
THROUGH EACH SITE. CONFINED THE TS AND MVFR CONDITIONS TO A 2 HOUR
PERIOD. SOME LOW VFR CEILINGS ARE LIKELY FOR A FEW HOURS BEHIND
THE RAIN...AND MVFR CEILINGS CANNOT BE RULED OUT.
SOUTH WINDS WILL INCREASE AND VEER TO WEST SOUTHWEST THROUGH THE
DAY. SUSTAINED WINDS IN THE TEENS AND GUSTS WELL INTO THE 20S ARE
EXPECTED...WITH THE STRONGEST WINDS AT KOWB. SKIES WILL CLEAR
QUICKLY EARLY THIS EVENING...AND WINDS WILL SUBSIDE TO UNDER 10KTS
WITH SUNSET.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...DRS
LONG TERM...RJP
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
102 PM CDT MON MAY 11 2015
.AVIATION...
LINE OF THUNDERSTORMS EXTENDS FROM HENDERSON IN SOUTH CENTRAL
LOUISIANA TO CAMERON LOUISIANA. THIS LINE IS MOVING TO THE
SOUTHEAST WHILE CELLS ARE MOVING TO THE NORTHEAST. VSBY AND
CEILINGS LWR W/ WINDS GUSTY IN AND AROUND TSTMS.
&&
.PREV DISCUSSION... /ISSUED 1108 AM CDT MON MAY 11 2015/
UPDATE...
BAND OF CONVECTION CONTINUES TO PROPAGATE SOUTHWARD ALONG THE
OUTFLOW BOUNDARY. THE LEADING EDGE OF THIS ACTIVITY WILL BE
REACHING THE I-10 CORRIDOR FROM BEAUMONT TO JENNINGS THEN BACK TO
THE NE TOWARD OPELOUSAS WITHIN THE NEXT HOUR. ADDITIONAL SCT
SHOWERS AND TSTMS ARE DEVELOPING ACRS PORTIONS OF ACADIANA AS
WELL. EXPECT THE SWD DEVELOPMENT OF THIS ACTIVITY TO SLOW OVER THE
NEXT FEW HOURS AS BOUNDARY ORIENTATION BECOMES MORE PARALLEL TO
THE MEAN FLOW ALOFT. OVERALL...EXPECT SCT TO NMRS SHOWERS AND
TSTMS TO CONTINUE THROUGH THE AFTN...MAINLY ALONG AND NORTH OF
I-10 AND ADJUSTED POP/WX GRIDS TO REFLECT THIS USING A BLEND OF
RECENT HIRES MODEL GUIDANCE. IN ADDITION...THE COMBINATION OF THE
ABV MENTIONED FACTORS AND AMPLE MOISTURE OVER THE REGION...THERE
IS THE POTENTIAL FOR SOME LOCALLY HEAVIER RAINFALL WHICH COULD
LEAD TO FLOODING OF URBAN AND LOW-LYING AREAS. THINK ANY FLOOD
RELATED PROBLEMS WILL BE LOCALIZED AND MINOR SO DO NOT THINK A
FLOOD WATCH WILL BE NECESSARY AT THIS TIME.
WITH WIDESPREAD CLOUDS AND SHOWERS CROSSING THE
AREA...TEMPERATURES ARE IN THE 60S ACRS THE NRN CWA WITH LOCATIONS
ALONG I-10 HAVING REACHED THE LOWER 80S JUST AHEAD OF THE LINE OF
CONVECTION. EXPECT TEMPS TO FALL BACK INTO THE 70S AS THE SHOWERS
REACH I-10. RECOVERY WILL DEPEND ON WHETHER ANY SUN CAN BREAK
THROUGH DURING THE AFTN...BUT HAVE ADJUSTED HOURLY TEMPS AND
DEWPOINTS BASED ON RECENT OBS AND TRENDED A LITTLE COOLER ON
HOURLY TEMPS THROUGH THE AFTN. ALSO ADJUSTED MAX TEMPS DOWNWARD
A BIT AS WELL...ESPECIALLY ACRS THE NRN ZONES. 24
PREV DISCUSSION... /ISSUED 644 AM CDT MON MAY 11 2015/
AVIATION...THE HIGH RESOLUTION SHORT RANGE MODEL TAKES THE BAND
OF SHOWERS AND THUNDERSTORMS APROACHING FROM THE NORTHWEST INTO
THE TERMINALS LATER THIS MORNING. POSSIBLE CONDITIONS AS LOW AS
LIFR CIGS WITH RAIN ASSUMING THE CURRENT ACTIVITY WEAKENS AS SOME
SIGNS HAVE INDICATED. SINCE ATMOSPHERE WOULD BE WORKED OVER BY THIS
AFTERNOON WILL GO WITH VFR CIGS WITH VCTS. LATE TNITE AS THE WEAK
FRONT APPROACHES, MVFR WITH LIGHT RAIN.
SWEENEY
PREV DISCUSSION... /ISSUED 343 AM CDT MON MAY 11 2015/
DISCUSSION...MAIN FORECAST ISSUE WILL BE POPS THROUGHOUT THE
WEEK.
LINE OF THUNDERSTORMS OVER NE TEXAS HAS SLOWLY SHIFTED SE DURING THE
NIGHT. LATEST HRRR MAY BE A LITTLE QUICK IN PUSHING THE LINE INTO
NW PART OF THE FORECAST AREA BY 12Z...BUT THERE IS CERTAINLY
POTENTIAL FOR CONVECTION DEVELOPING AHEAD OF THE LINE BY THAT
TIME. EVEN IF LINE WEAKENS...REMNANT BOUNDARIES COMBINED WITH
RICH THTE AIR WILL LIKELY KEEP GOOD COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR TODAY ESPECIALLY ACROSS EAST TEXAS AND CENTRAL
LOUISIANA. WILL TWEAK CURRENT POPS FORECAST FOR TODAY BUT OVERALL
NOT MUCH CHANGE FROM PREVIOUS FORECASTS.
FOR TUESDAY...MODELS SHOW VIGOROUS SHORTWAVE IN UPPER SW FLOW AND
THIS SHOULD FURTHER ENHANCE SHOWER AND THUNDERSTORM CHANCES.
A SERIES OF UPPER SHORT WAVE TROUGHS WILL MOVE THROUGH THE
WESTERN U.S. THROUGH THE WEEK. ALSO...MODELS ARE SHOWING A BROAD
NEGATIVELY TILTED TROUGH BECOMING ESTABLISHED OVER THE WEST COAST
BY LATE IN THE WEEK. AT THE SURFACE...FRONTAL BOUNDARY IS
FORECASTED TO MOVE INTO THE AREA AND STALL THROUGH AT LEAST
WEDNESDAY. A VERY MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE
WEEK. WILL THEREFORE MAINTAIN MAINLY DIURNAL SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK. WILL LOWER POPS
SLIGHTLY OVER THE WEEKEND AS SURFACE BOUNDARY SHOULD BE LESS
DEFINED OR DIFFUSE.
MARINE....WILL ALLOW SCEC TO EXPIRE AT 5 AM FOR INNER AND OUTER
WATERS. WITH BOUNDARY APPROACHING THE AREA ON TUESDAY...GRADIENT
SHOULD WEAKEN AND LOW LEVEL FLOW SHOULD BECOME MORE EASTERLY.
PROGRESSION OF HIGH PRESSURE TOWARD THE EAST COAST WILL ALLOW FOR
A WEAK SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEK.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 68 79 65 83 / 80 70 30 50
LCH 71 83 70 83 / 50 70 30 40
LFT 72 84 70 85 / 40 60 30 40
BPT 72 82 71 83 / 60 70 30 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...19
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1108 AM CDT MON MAY 11 2015
.UPDATE...
BAND OF CONVECTION CONTINUES TO PROPAGATE SOUTHWARD ALONG THE
OUTFLOW BOUNDARY. THE LEADING EDGE OF THIS ACTIVITY WILL BE
REACHING THE I-10 CORRIDOR FROM BEAUMONT TO JENNINGS THEN BACK TO
THE NE TOWARD OPELOUSAS WITHIN THE NEXT HOUR. ADDITIONAL SCT
SHOWERS AND TSTMS ARE DEVELOPING ACRS PORTIONS OF ACADIANA AS
WELL. EXPECT THE SWD DEVELOPMENT OF THIS ACTIVITY TO SLOW OVER THE
NEXT FEW HOURS AS BOUNDARY ORIENTATION BECOMES MORE PARALLEL TO
THE MEAN FLOW ALOFT. OVERALL...EXPECT SCT TO NMRS SHOWERS AND
TSTMS TO CONTINUE THROUGH THE AFTN...MAINLY ALONG AND NORTH OF
I-10 AND ADJUSTED POP/WX GRIDS TO REFLECT THIS USING A BLEND OF
RECENT HIRES MODEL GUIDANCE. IN ADDITION...THE COMBINATION OF THE
ABV MENTIONED FACTORS AND AMPLE MOISTURE OVER THE REGION...THERE
IS THE POTENTIAL FOR SOME LOCALLY HEAVIER RAINFALL WHICH COULD
LEAD TO FLOODING OF URBAN AND LOW-LYING AREAS. THINK ANY FLOOD
RELATED PROBLEMS WILL BE LOCALIZED AND MINOR SO DO NOT THINK A
FLOOD WATCH WILL BE NECESSARY AT THIS TIME.
WITH WIDESPREAD CLOUDS AND SHOWERS CROSSING THE
AREA...TEMPERATURES ARE IN THE 60S ACRS THE NRN CWA WITH LOCATIONS
ALONG I-10 HAVING REACHED THE LOWER 80S JUST AHEAD OF THE LINE OF
CONVECTION. EXPECT TEMPS TO FALL BACK INTO THE 70S AS THE SHOWERS
REACH I-10. RECOVERY WILL DEPEND ON WHETHER ANY SUN CAN BREAK
THROUGH DURING THE AFTN...BUT HAVE ADJUSTED HOURLY TEMPS AND
DEWPOINTS BASED ON RECENT OBS AND TRENDED A LITTLE COOLER ON
HOURLY TEMPS THROUGH THE AFTN. ALSO ADJUSTED MAX TEMPS DOWNWARD
A BIT AS WELL...ESPECIALLY ACRS THE NRN ZONES. 24
&&
.PREV DISCUSSION... /ISSUED 644 AM CDT MON MAY 11 2015/
AVIATION...THE HIGH RESOLUTION SHORT RANGE MODEL TAKES THE BAND
OF SHOWERS AND THUNDERSTORMS APROACHING FROM THE NORTHWEST INTO
THE TERMINALS LATER THIS MORNING. POSSIBLE CONDITIONS AS LOW AS
LIFR CIGS WITH RAIN ASSUMING THE CURRENT ACTIVITY WEAKENS AS SOME
SIGNS HAVE INDICATED. SINCE ATMOSPHERE WOULD BE WORKED OVER BY THIS
AFTERNOON WILL GO WITH VFR CIGS WITH VCTS. LATE TNITE AS THE WEAK
FRONT APPROACHES, MVFR WITH LIGHT RAIN.
SWEENEY
PREV DISCUSSION... /ISSUED 343 AM CDT MON MAY 11 2015/
DISCUSSION...MAIN FORECAST ISSUE WILL BE POPS THROUGHOUT THE
WEEK.
LINE OF THUNDERSTORMS OVER NE TEXAS HAS SLOWLY SHIFTED SE DURING THE
NIGHT. LATEST HRRR MAY BE A LITTLE QUICK IN PUSHING THE LINE INTO
NW PART OF THE FORECAST AREA BY 12Z...BUT THERE IS CERTAINLY
POTENTIAL FOR CONVECTION DEVELOPING AHEAD OF THE LINE BY THAT
TIME. EVEN IF LINE WEAKENS...REMNANT BOUNDARIES COMBINED WITH
RICH THTE AIR WILL LIKELY KEEP GOOD COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR TODAY ESPECIALLY ACROSS EAST TEXAS AND CENTRAL
LOUISIANA. WILL TWEAK CURRENT POPS FORECAST FOR TODAY BUT OVERALL
NOT MUCH CHANGE FROM PREVIOUS FORECASTS.
FOR TUESDAY...MODELS SHOW VIGOROUS SHORTWAVE IN UPPER SW FLOW AND
THIS SHOULD FURTHER ENHANCE SHOWER AND THUNDERSTORM CHANCES.
A SERIES OF UPPER SHORT WAVE TROUGHS WILL MOVE THROUGH THE
WESTERN U.S. THROUGH THE WEEK. ALSO...MODELS ARE SHOWING A BROAD
NEGATIVELY TILTED TROUGH BECOMING ESTABLISHED OVER THE WEST COAST
BY LATE IN THE WEEK. AT THE SURFACE...FRONTAL BOUNDARY IS
FORECASTED TO MOVE INTO THE AREA AND STALL THROUGH AT LEAST
WEDNESDAY. A VERY MOIST AIRMASS WILL REMAIN IN PLACE THROUGH THE
WEEK. WILL THEREFORE MAINTAIN MAINLY DIURNAL SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REMAINDER OF THE WEEK. WILL LOWER POPS
SLIGHTLY OVER THE WEEKEND AS SURFACE BOUNDARY SHOULD BE LESS
DEFINED OR DIFFUSE.
MARINE....WILL ALLOW SCEC TO EXPIRE AT 5 AM FOR INNER AND OUTER
WATERS. WITH BOUNDARY APPROACHING THE AREA ON TUESDAY...GRADIENT
SHOULD WEAKEN AND LOW LEVEL FLOW SHOULD BECOME MORE EASTERLY.
PROGRESSION OF HIGH PRESSURE TOWARD THE EAST COAST WILL ALLOW FOR
A WEAK SOUTHERLY FLOW FOR THE REMAINDER OF THE WEEK.
04
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 83 68 79 65 / 80 80 70 30
LCH 83 71 83 70 / 70 50 70 30
LFT 84 72 84 70 / 50 40 60 30
BPT 84 72 82 71 / 80 60 70 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
142 PM EDT MON MAY 11 2015
.SYNOPSIS...
VERY WARM WEATHER WILL CONTINUE TODAY UNTIL THE PASSAGE OF A
COLD FRONT OVERNIGHT. THUNDERSTORM CHANCES WILL INCREASE THIS
AFTERNOON AND TONIGHT AS THE FRONT APPROACHES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN CHANGE WAS TO TRY TO PINPOINT TIMING OF EXPECTED CONVECTIVE
ACTIVITY LATER TODAY. HRRR RUNS SEEM TO HAVE A GOOD HANDLE ON
CURRENT ACTIVITY AND HAVE BEEN FAIRLY CONSISTENT IN BRINGING
ACTIVITY TO NEAR ZZV BY 22Z AND TO THE PA/WV BORDER BY 00Z.
MIDLEVEL WINDS DO INCREASE INTO THE 40-50 KNOT RANGE AROUND 00Z IN
OHIO...AND EXPECTED INVERTED-V SOUNDINGS INDICATE SOME DOWNDRAFT
POTENTIAL AS WELL. SPC HAS OHIO OUTLOOKED IN SLIGHT RISK AREA AND
THIS LOOKS REASONABLE AS A FEW STRONG TO DAMAGING WIND GUSTS
APPEAR POSSIBLE. ADDED GUSTY WIND WORDING TO GRIDS/ZFP. MOST OTHER
CHANGES AMOUNTED TO TWEAKS. CL
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH THE FRONT TIMED TO APPROACH THIS EVENING...WE WILL LOSE THE
INSTABILITY NEEDED FOR A STRONG ORGANIZED LINE OF STORMS TO
CONTINUE. ADDITIONALLY...AS THE FRONT IS NOT MUCH MORE THEN A
RIPPLE IN ISOBARS WITH ONLY WEAK COLD AIR ADVECTION BEHIND IT AND
A MINOR SHIFT IN SURFACE WINDS. I WOULD EXPECT A LINE OF SHOWERS
AND STORMS TO ROLL THROUGH WITH THIS FEATURE...BUT SEE THE
ACTIVITY WEAKENING AS IT RUSHES TO THE EAST.
UPPER TROUGH WILL PIVOT A SECONDARY FRONT...TIED TO A MUCH COOLER
AIRMASS...THROUGH THE REGION BY LATE TUESDAY MORNING. WILL NEED TO
KEEP IN THE CHANCE FOR SHOWERS AND POSSIBLY A STORM UNTIL THIS
BOUNDARY CROSSES. TEMPERATURES MAY ACTUALLY STAY ELEVATED UNTIL
THIS BOUNDARY PASSES...WITH HIGH TEMPERATURE BEING REALIZED EARLY
BEFORE A GRADUAL DECLINE IS EXPECTED. THE DOWNWARD TREND SHOULD
CONTINUE TUESDAY NIGHT AND WEDNESDAY AS THE GREAT LAKES REGION
REMAINS IN NORTHWEST FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
QUIET AND COOL BEGINNING TO THE LONG TERM PERIOD. TEMPERATURES
WILL MODERATE BY THE END OF THE WEEK AND THROUGH THE WEEKEND.
LOOKS TO BE A MORE ACTIVE WEATHER PATTERN SETTING UP FOR SATURDAY
AND SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS FOR THE MOST PART DURING THE AFTERNOON HOURS...SAVE
FOR SCATTERED TSRA THAT WILL POP UP IN INSTABILITY. HANDLED THIS
INITIAL ACTIVITY WITH VCTS FOR NOW...WILL AMEND IF THE THREAT
INCREASES AT ANY ONE TERMINAL. SW BREEZES WILL GUST TO 15-20 KNOTS
AT TIMES. EXPECT A MORE SOLID LINE OF TSRA WITH A PREFRONTAL
TROUGH...CROSSING THE AREA BETWEEN 23Z AND 06Z. MVFR/BRIEF IFR
VISIBILITIES CAN BE EXPECTED WITH THESE STORMS....WHICH COULD ALSO
CONTAIN 30-40 KNOT GUSTS AT LEAST...ESPECIALLY IN SOUTHEAST OHIO.
MAINLY SHRA AND LINGERING MVFR CIGS ARE EXPECTED AHEAD OF THE
ACTUAL FROPA...WHICH OCCURS MAINLY AFTER SUNRISE ON TUESDAY. THESE
SHRA WILL TAPER OFF BY MIDMORNING...BUT WIND WILL PICK UP
CONSIDERABLY OUT OF THE WSW...GUSTING TO BETWEEN 20 AND 30 KNOTS.
VFR WILL BECOME ESTABILISHED AREAWIDE BY THE END OF THE TAF
PERIOD.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS IS EXPECTED WITH MID WEEK
MORNING FOG AND STRATUS AS COOLER AIR SETTLES OVER THE REGION IN
THE WAKE OF THE FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT MON MAY 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 421 PM EDT MON MAY 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW THE MID LEVEL LOW THAT WAS
OVER WRN NEBRASKA/SD 24HRS AGO NOW CENTERED IN WCNTRL MN. AHEAD OF
FEATURE...WARM CONVEYOR BELT MOISTURE RIBBON EXTENDS FROM THE LWR
MISSISSIPPI VALLEY TO THE WRN GREAT LAKES. RESULT HAS BEEN NMRS SHRA
SPREADING ACROSS THE FCST AREA TODAY. A FEW TSTMS WERE NOTED THIS
MORNING OVER THE W HALF OF UPPER MI. AT THE SFC...LOW PRES LOCATED
IN CNTRL MN IS BECOMING LESS WELL-DEFINED WITH TENDENCY FOR LOW PRES
REDEVELOPMENT AT THE TRIPLE POINT FARTHER E. OCCLUDED FRONT IS
APPROACHING THE MI/WI BORDER AS OF 20Z.
AS THE WARM CONVEYOR MOISTURE RIBBON TRANSLATES E...WIDESPREAD SHRA
NOW OVER THE E HALF OF THE FCST AREA WILL ALSO SHIFT E AND OUT OF
THE AREA IN THE NEXT FEW HRS. FOG AND SOME -DZ WILL PERSIST IN THE
UPSLOPE FLOW OFF LAKE SUPERIOR INTO THE KEWEENAW AND WRN PORTIONS OF
NCNTRL UPPER MI...AND A FEW SHRA MAY DEVELOP NEAR THE OCCLUDED FRONT
WHICH SHOULD LIFT INTO OR THRU MUCH OF CNTRL AND ERN UPPER MI THIS
EVENING. OTHERWISE...AS MID LEVEL LOW OPENS UP AND UPPER TROF MOVES
E INTO THE WRN GREAT LAKES TONIGHT...DEEPER MOISTURE WILL WRAP BACK
INTO THE AREA FROM THE N AND W. AIDED BY DEEP CYCLONIC FLOW...SHRA
WILL SPREAD BACK INTO THE FCST AREA...ESPECIALLY ACROSS THE W. AS
CAA INCREASES OVERNIGHT...FCST SOUNDINGS/WETBULB ZERO HEIGHTS
SUGGEST POTENTIAL FOR SNOW TO MIX WITH THE RAIN OVER THE HIGH
TERRAIN OF THE W LATE TONIGHT.
AS TROF CONTINUES TO SHIFT E TUE...DEEP LAYER QVECTOR DIVERGENCE
OVERSPREADS THE AREA WITH HEIGHTS BEGINNING TO RISE...MORE
SUBSTANTIALLY IN THE AFTN. THIS WILL TEND TO DIMINISH THE WRAP
AROUND PCPN WITH TIME...BUT THIS WILL BE COUNTERACTED BY SHARP
CYCLONIC FLOW AND CONSIDERABLE LOW TO MID LEVEL MOISTURE THAT
LINGERS THRU THE DAY. THIS WILL RESULT IN PCPN BEING MOST PERSISTENT
IN THE AREAS THAT SEE UPSLOPING UNDER NW TO N WINDS. DOWNSLOPE AREAS
WILL SEE PCPN DIMINISH OR END. CONTINUED CAA WILL DROP 850MB TEMPS
TO -3 TO AS LOW AS -6C...AND THIS WILL RESULT IN RAIN MIXING WITH
SNOW...MAINLY OVER THE HIGHER TERRAIN OF THE W AND CNTRL. PCPN WILL
LIKELY CHANGE TO ALL SNOW AT LEAST FOR A TIME OVER THE HIGH TERRAIN
OF THE W HALF AS LOWEST 850MB TEMPS ARE FCST THERE. THAT AREA WILL
ALSO HAVE THE BEST CHANCE FOR A LITTLE SNOW ACCUMULATION ON GRASSY
SFCS. IT WILL BE AN UNSEASONABLY COLD DAY WITH TEMPS AROUND 20
DEGREES BLO NORMAL ACROSS THE W AND N WHERE TEMPS WILL STRUGGLE TO
GET MUCH ABOVE 40F. ACROSS THE SCNTRL...TEMPS MAY SNEAK INTO THE LWR
50S. BLUSTERY WINDS WILL ADD TO THE CHILL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 255 PM EDT MON MAY 11 2015
WILL STILL HAVE SOME LINGERING MAINLY SNOW SHOWERS /WITH A FEW RAIN
SHOWERS OR AREAS OF DRIZZLE MIXED IN/ TUESDAY NIGHT OVER THE N HALF
OF UPPER MI. THE BEST CHANCE OF PRECIP WILL BE N CENTRAL AS
FAVORABLE N-NNW WINDS RESIDE THERE FROM THE SFC-850MB. TEMPERATURES
WILL BE COOLING INTO THE LOW 30S OVERNIGHT...WITH LOCATIONS OVER THE
INTERIOR W HALF FALLING INTO THE MID 20S AS WINDS BECOME NEARLY CALM
AND DRIER AIR WORKS IN AND 850MB TEMPS BEGIN TO WARM SLIGHTLY FROM -
4 TO -6C...TO AROUND -3C.
HIGH PRESSURE WILL BE STRETCHING FROM HUDSON BAY THROUGH MANITOBA
AND MN...DOWN THROUGH THE MS VALLEY AT 00Z WEDNESDAY. LOOK FOR THE
AREA OF HIGH PRESSURE TO BUILD ACROSS THE UPPER GREAT LAKES THROUGH
WEDNESDAY...WITH DRY WEATHER FIGURED INTO AT LEAST WEDNESDAY
EVENING. WAA WILL TAKE HOLD AT THE SFC ON MAINLY S WINDS OVER THE W
HALF OF THE CWA...WITH AFTERNOON HIGHS IN THE 50S FOR MOST LOCATIONS
/EXCLUDING THE COOLER N CENTRAL AND E
LAKE SUPERIOR SHORELINE/ AS 850MB TEMPS REBOUND TO AROUND 4C W TO 1C
E.
PRECIP COULD SLIDE IN AS EARLY AS LATE WEDNESDAY AFTERNOON SW /GFS
SOLUTION/. THIS WOULD BE ALONG THE SW AS AN INITIAL FRONTAL BOUNDARY
SHIFTS TO OUR N. THE MAIN CONCERN IS THAT THE LOWER LEVELS WILL BE
TOO DRY WITH THE SFC RIDGE STILL OVER MUCH OF THE AREA WITH THIS
BOUNDARY/SHORTWAVE ROUNDING THE 500MB RIDGE. WILL CONTINUE TO GO
WITH A MINIMAL PRECIP SOLUTION FOR THIS PERIOD. THE SFC HIGH WILL
SHIFT ACROSS THE ENTIRE GREAT LAKES REGION WEDNESDAY NIGHT...WITH
SLOWLY INCREASING S FLOW OVER UPPER MI PUSHING IN INCREASED MOISTURE
AS 850MB TEMPS RUMP TO AROUND 8C OVER THE SW.
THE APEX OF THE 500MB RIDGE WILL BE ACROSS THE AREA THURSDAY
AFTERNOON...WITH FCST MODELS INDICATING A NEARING EMBEDDED 500MB
TROUGH IN THE SW FLOW OVER THE N PLAINS AND W MN. THE GFS HAS A
DEEPER/WRAPPED UP SFC LOW OVER THE CENTRAL PLAINS OFF THE GFS IS NOT
QUITE A S STRONG AS THE ECMWF...ESPECIALLY THE PREVIOUS 11/06Z RUN.
THIS LEADS TO ONLY MODERATE CONFIDENCE IN THE FCST BEYOND THURSDAY.
THE DIFFERENCE SHOWS UP WELL IN THE MODEL QPF...WITH THE 11/06Z GFS
SHOWING 24HR PRECIP OF 0.75-1.45IN BY 00Z SATURDAY. THE 11/00Z ECMWF
ON THE OTHER HAND RANGES FROM LESS THAN 0.10IN ACROSS THE KEWEENAW
PENINSULA...TO 0.5IN OVER FAR S MENOMINEE CO. THIS WILL BE AS THE
SFC LOW OFF THE GFS TRACKS FROM THE CENTRAL PLAINS TO N LAKE MI BY
00Z SATURDAY. THE CANADIAN THE ECMWF KEEP A RIDGE ACROSS LAKE
SUPERIOR AND MUCH OF UPPER MI DURING THE SAME TIME PERIOD. ON A
POSITIVE NOTE...THE 11/12Z GFS CAME IN AT LEAST A LITTLE LESS
INTENSE WITH THE SFC LOW...AND DROPS ABOUT 1/2 AS MUCH PRECIP.
AN ADDITIONAL LOW DEVELOPING OFF THE N ROCKIES TOWARDS THE END OF
THE WORK WEEK WILL LIKELY BE SET UP ACROSS MT AND WY SATURDAY
MORNING...AND MOVE ACROSS THE DAKOTAS SATURDAY NIGHT...AND THE UPPER
GREAT LAKES ON MONDAY. THE 12Z RUNS HAVE BECOME MUCH MORE IN LINE
WITH THE SFC LOW TRACKING OVER E MN/FAR W LAKE SUPERIOR BY 06Z
MONDAY. THE RESULT IS AT LEAST MODERATE CONFIDENCE IN RAIN. WILL GO
WITH LIKELY PRECIP FOR SUNDAY NIGHT ACROSS MOST OF THE CWA. SO FOR
THE UPCOMING WEEKEND IT LOOKS TO BE MAINLY DRY SATURDAY...WITH WET
WEATHER APPROACHING SUNDAY AND POSSIBLY LINGERING INTO MONDAY AS THE
SFC LOW SLOWLY EDGES E OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 135 PM EDT MON MAY 11 2015
LOW PRES SYSTEM WILL MOVE E ACROSS THE UPPER GREAT LAKES TONIGHT AND
THEN E TO QUEBEC TUE. ABUNDANT LOW-LEVEL MOISTURE WILL GENERALLY
SUPPORT IFR TO LIFR CONDITIONS AND -SHRA AT KIWD/KCMX/KSAW THRU THIS
FCST PERIOD WITH THE LOWEST CONDITIONS OCCURRING AT TERMINALS
EXPERIENCING UPSLOPE WINDS. FOR THE REMAINDER OF THE AFTN...THE
LOWEST CONDITIONS (VLIFR) WILL OCCUR AT KCMX. SLIGHTLY DRIER AIR
TRYING TO WORK N THRU WI MAY REACH KIWD AND KSAW FOR A TIME LATE
THIS AFTN/EVENING WHICH MAY ALLOW FOR A PERIOD OF MVFR CONDITIONS.
THIS IS MORE LIKELY TO HAPPEN AT KSAW. COLDER AIR WRAPPING INTO THE
AREA BEHIND THE LOW SHOULD BE COLD ENOUGH TO RESULT IN -SHRA MIXING
WITH OR CHANGING OVER TO -SHSN TUE MORNING. CHANGE OVER TO ALL SNOW
IS MORE LIKELY TO OCCUR AT KIWD/KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 421 PM EDT MON MAY 11 2015
ONGOING MARGINAL GALES OVER THE WRN PORTION OF LAKE SUPERIOR WILL
CONTINUE TO DIMINISH...FALLING BLO GALE FORCE EARLY THIS EVENING...
AS PRES GRADIENT WEAKENS AND WINDS BACK DUE TO LOW PRES SHIFTING
ACROSS UPPER MI AND ERN LAKE SUPERIOR. ON THE BACK SIDE OF THE
LOW...NNW WINDS WILL INCREASE TO 20-30KT ACROSS CNTRL AND ERN LAKE
SUPERIOR LATE TONIGHT/TUE MORNING. MAY SEE A FEW GALE FORCE GUSTS
TUE MORNING OVER SCNTRL LAKE SUPERIOR AROUND GRANITE ISLAND DUE TO
LOCAL COASTAL CONVERGENCE. WINDS WILL DIMINISH FROM W TO E TUE
AFTN/TUE NIGHT WITH LIGHT WINDS MOSTLY UNDER 15KT TO FOLLOW FOR
WED/THU AS HIGH PRES BUILDS INTO THE UPPER LAKES WED AND THEN
LINGERS INTO THU. AS THE HIGH PRES SHIFTS E AND A WEAK LOW PRES
PASSES BY TO THE S...WINDS MAY INCREASE SOME FOR THU NIGHT/FRI
BEFORE DIMINISHING AGAIN ON SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
329 PM EDT MON MAY 11 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 328 PM EDT MON MAY 11 2015
A COLD FRONT WILL COME THROUGH THE AREA TONIGHT ENDING OVER A
WEEKS WORTH OF UNSEASONABLY WARM TEMPEATURES. THERE WILL BE
SHOWERS AND A FEW THUNDERSTORMS AHEAD OF THE COLD FRONT THIS
EVENING...THEN A FEW LIGHT RAIN SHOWERS TUESDAY AS CHILLY WESTERLY
WINDS KEEP AFTERNOON TEMPERATURES IN THE 50S. SKIES WILL BECOME
PARTLY CLOUDY TUESDAY NIGHT REMAIN SO ON WEDNESDAY. ANOTHER STORM
SYSTEM WILL BRING MORE SHOWERS AND POSSIBLY THUNDERSTORMS LATER
THIS WEEK INTO THE WEEKEND. IT WILL WARM UP AGAIN BY THE END TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 328 PM EDT MON MAY 11 2015
THE MAIN ISSUE IS THE THREAT FOR SEVERE STORMS (NOT MUCH) THEN THE
CHANCE FOR LIGHT RAIN SHOWERS TUESDAY AND POSSIBLE FROST TOMORROW
NIGHT.
THE LATEST RAP MODEL SHOWS THE LOW LEVEL JET CORE LIFTING
NORTHEAST FROM SOUTHWEST LOWER MICHIGAN EARLY THIS AFTERNOON TO
THE THUMB AREA BY EARLY THIS EVENING. THE MOST UNSTABLE CAPE
(OVER 500 J/KG) STAYS JUST EAST OF OUR CWA LATE THIS AFTERNOON.
WHILE THERE IS GOOD DEEP LAYER SHEAR...THE RAIN COOLED AIR OVER
MOST OF OUR CWA WILL MITIGATE MOST OF THE SEVERE WEATHER THREAT.
POSSIBLY ISOLATED DAMAING WINDS COULD HAPPEN OVER OUR EXTREME
SOUTHEAST COUNTIES EARLY THIS EVENING.
OTHERWISE THE AREA OF RAIN WILL MOVE OUT BY MID EVENING. THEN THE
DRY SLOT MOVES IN BEHIND THE COLD FRONT SO SKIES WILL CLEAR AT
LEAST PARTLY. WE THEN GET WRAP AROUND COLD AIR ADVECTION
INSTABLTLY SHOWERS (MOSTLY SPRLINKLES) TUESDAY AND IT WILL BE
BREEZY AND CHILLY WITH HIGHS ONLY IN THE 50S.
THE UPPER TROUGH MOVES OUT QUICKLY TUESDAY NIGHT ALLOWING FOR SOME
CLEARING. FROST IS POSSIBLE OVER NORTHERN AREAS WENESDAY MORNING.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 328 PM EDT MON MAY 11 2015
AS HIGH PRESSURE MOVES EAST THURSDAY LOW PRESSURE WILL MOVE TOWARD
THE GREAT LAKES. CONFIDENCE IS INCREASING THAT WE/LL SEE SOME
PRECIPITATION MOVE OVER THE CWA THURSDAY NIGHT AND FRIDAY. ADDED
THUNDER TO THE GRIDS FRIDAY AS LI/S FALL TO AROUND -2C AND CAPE
INCREASES TO 1K J/KG. MUCH OF THE PCPN WILL BE EAST OF THE CWA BY
SATURDAY AS THE SFC LOW MOVES AWAY. HOWEVER WE/LL KEEP LOW POPS IN
TO COVER THE UPPER TROUGH.
CHANCES FOR TSRA WILL INCREASE TOWARD THE BEGINNING OF NEXT WEEK AS
A STRONGER COLD FRONT MOVES TOWARD THE CWA. STRONG SOUTH FLOW AHEAD
OF IT WILL SEND ABUNDANT MOISTURE NORTHWARD AND CREATE SOME
INSTABILITY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 746 AM EDT MON MAY 11 2015
LIFR CONDITIONS ARE WIDESPREAD AT THE TAF SITES AT 12Z. A WARM
FRONT IS PUSHING NORTH FROM THE INTERSTATE 94 CORRIDOR WITH MUCH
IMPROVED CONDITIONS TO THE SOUTH OF IT...VFR. CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH THE COURSE OF THE MORNING...AT LEAST
TO MVFR IF NOT VFR FOR A SHORT TIME AS THE WARM FRONT LIFTS
NORTHWARD.
THIS AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD MOVE INTO THE
AREA FROM THE SOUTHWEST. AT THIS POINT HAVE VCTS WORDING. THE
EARLY AFTERNOON SET OF TAFS MAY BE ABLE TO PROVIDE BETTER TIMING
IN REGARD TO THE PRECIPITATION. MOST LIKELY MVFR MUCH OF THE
AFTERNOON WITH CEILINGS AND POTENTIALLY VISIBILITIES.
THE SHOWERS...STORMS AND POOR AVIATION CONDITIONS SHOULD SWEEP
EAST THIS EVENING. THERE IS A CHANCE THAT MVFR CEILINGS COULD
REDEVELOP OVERNIGHT...BUT KEPT THINGS VFR AT THIS POINT.
&&
.MARINE...
ISSUED AT 328 PM EDT MON MAY 11 2015
THE STRONG WINDS BEHIND OUR SYSTEM WILL LEAD TO 4 TO 6 FOOT WAVES
AND WINDS TO 30 KNOTS BY MID MORNING TUESDAY. AS A RESULT I ISSUES
A SCA.
&&
.HYDROLOGY...
ISSUED AT 1222 PM EDT MON MAY 11 2015
ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF
AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE
ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD
CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT
WILL REMAIN BELOW FLOOD STAGE.
AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN
RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS
SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM TO 6 PM EDT TUESDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...93
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1224 PM EDT MON MAY 11 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 320 AM EDT MON MAY 11 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY WITH SOME SEVERE
WEATHER POSSIBLE IN THE FORM OF DAMAGING WIND GUSTS AND PERHAPS
ISOLATED TORNADOES. A COLD FRONT MOVES IN TONIGHT BRINGING VERY
CHILLY AIR FOR TUESDAY WITH HIGHS ONLY IN THE 50S ALONG WITH GUSTY
WESTERLY WINDS. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY
BUT MORE PRECIP IS POSSIBLE FOR LATE IN THE WEEK AND PORTIONS OF
THE WEEKEND.
&&
.UPDATE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
I UPDATED THE GRIDS TO SHOW A MORE REALIST PROGRESSION OF THE
CONVECTION THAT EXPECTED TO MOVE THROUGH THE AREA THIS AFTERNOON
AHEAD OF THE COLD FRONT. I ALSO DROPPED THE FOG ADVISORY AND
REPLACED IT WITH AREAS OF FOG INTO EARLY AFTERNOON BUT FOR THE
MOST PART THE FOG IS GONE.
AS FOR THE SEVERE WEATHER THREAT... CLEARLY CLOUD COVER IS AN
ISSUE. THAT WOULD DECREASE THE THREAT FOR STRONG TO SEVERE STORMS
OVER OUR CWA THIS AFTERNOON. EVEN SO THE LATEST RAP MODEL...WHICH
IS DONE WELL WITH THE CURRENT AREA OF SHOWERS AND WHERE THE
CURRENT THUNDERSTORMS ARE...SHOWS MAX WIND SPEED CORE ON THE LOW
LEVEL JET DEVELOPING OVER WRN IN AND SOUTHWEST LWR MI BY NOON BUT
AT THAT POINT WINDS ARE MOSTLY UNDER 35 KNOTS. BY 4 PM THE RAP 14Z
MODEL SHOWS A CORE OF 40 KNOT WINDS ON THE LOW LEVEL JET NEAR JXN
MOVING NORTHEAST...REACHING THE FNT AREA BY EARLY EVENING. AT THE
SAME TIME THE ENTRANCE REGION TO A 110 KNOT 300 MB JET IS MOVING
NORTH NORTHEAST ACROSS LAKE MICHIGAN. THE PUTS MOST OF SOUTHWEST
MICHIGAN IN A FAVORABLE PLACE FOR STRONG TO SEVERE THUNDERSTORMS.
THE MOST UNSTABLE CAPE (OVER 500 J/KG) STAYS SOUTH OF A LINE FROM
AZO TO LAN TO FNT. THIS TELLS ME THE THREAT FOR STRONG TO SEVERE
STORMS IS MOSTLY IN THE I-69 AREA (MORE OR LESS) DURING THE MID
AFTERNOON. ELSESWHERE WILL LIKELY SEE SHOWERS AND
THUNDERSTORMS... WITH A LESSER THREAT FOR STRONG TO SEVERE STORMS.
ALSO THIS TELLS ME THE GREATEST THREAT IS FOR DAMAGING WINDS SINCE
THE CAPE IS NOT ALL THAT GREAT IN THE -10 TO -30C RANGE ON THE
LATEST RAP MODEL SOUNDINGS NEAR JXN AND LAN.
UPDATE ISSUED AT 626 AM EDT MON MAY 11 2015
WILL BE ISSUING A DENSE FOG ADVISORY SHORTLY FOR THE TWO ROWS OF
COUNTIES NORTH OF THE I94 ROW. FEEL THAT CONDITIONS ARE IMPROVING
AND WILL CONTINUE TO IMPROVE ALONG I94...SO LEFT THAT ROW OUT OF
THE DENSE FOG ADVISORY FOR THE TIME BEING. THE DENSE FOG ADVISORY
WILL INCLUDE HOLLAND...GRAND RAPIDS...LANSING AND HASTINGS. THE
FOG IS MOST THICK JUST NORTH OF THE WARM FRONT WHICH IS LIFTING
NORTH. THE WARM FRONT AT 600AM WAS LOCATED ALONG I94 LIFTING
NORTH. OB SITES IN THE FAR SOUTHERN ROW OF COUNTIES ALONG THE
MI/IN LINE HAVE IMPROVED SUBSTANTIALLY WITH THIS TREND MOVING
NORTH. THE ADVISORY WILL RUN THROUGH 11AM.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
FORECAST CONCERNS DEAL WITH THE THREAT FOR STRONG TO SEVERE THUNDERSTORMS
PRIMARILY THIS AFTERNOON AND EVENING. OVERALL...THERE LOOKS TO BE A MAIN WINDOW
OF OPPORTUNITY FROM 17Z TO 00Z FOR ANY SEVERE WEATHER...WITH THE PRIMARY THREAT
BEING DAMAGING WIND GUSTS AND A SECONDARY CONCERN BEING ISOLATED TORNADOES.
MANY INGREDIENTS ARE COMING TOGETHER TODAY TO SUPPORT THE CONTINUED THREAT FOR
SEVERE THUNDERSTORMS IN SPITE OF AN ENVIRONMENT THAT WILL FEATURE ONLY MODEST
CAPE. GOOD POSITIONING WITH RESPECT TO THE UPPER LEVEL JET (STRONGER DIVERGENCE
SHOWN TO OVERSPREAD THE SOUTHERN AND EASTERN CWA BY 18Z) ALONG WITH MID LEVEL
VORT LOBES AND A STRONG LLJ OF 50 KTS ACROSS NORTHERN INDIANA ARE THE MAIN
SYNOPTIC FEATURES OF NOTE. SPEAKING OF THE LLJ...THERE LOOKS TO BE DECENT WIND
CONVERGENCE AT THE NOSE OF THE JET ACROSS SW AND S CENTRAL LOWER MI. MOISTURE
POOLING AND CONVECTIVE DEVELOPMENT LOOK LIKELY ACROSS A GOOD PORTION OF THE
CWA...INCLUDING BUT NOT LIMITED TO WHERE THE SLIGHT RISK AREA IS OUTLINED
FOR TODAY.
WHILE SFC BASED CAPE WILL BE REALIZED AS THE WARM FRONT PUSHES NORTH TODAY...IT
WILL NOT BE SUBSTANTIAL...ONLY ON THE ORDER OF A FEW HUNDRED JOULES/KG MAINLY
FROM I-96 TO THE SOUTH. HOWEVER...COMPENSATING FOR THE MARGINAL INSTABILITY
WILL BE STRONG LOW LEVEL WIND SHEAR AND ELEVATED STORM RELATIVE
HELICITY...WHICH INTRODUCES A THREAT FOR ISOLATED TORNADOES. GFS BUFKIT
SOUNDING FOR AZO AT 18Z SHOWS 0-2KM SHEAR OF AROUND 45 KTS AND 0-1KM SRH OF 235
M2/S2. THE SPC SREF SIG TOR PARAMETER SHOWS A 30% PROBABILITY OF >=1 FOR OUR
SOUTH CENTRAL CWA.
THE CONVECTION ALLOWING MODELS SUPPORT A LINEAR LINE BEING THE PRIMARY
CONVECTIVE MODE...WITH SOME SUGGESTION THAT A FEW DISCRETE CELLS COULD FIRE
AHEAD OF THE LINE ESPECIALLY EAST OF A AZO TO LAN LINE. THE NSSL WRF AND HRRR
BOTH SUGGEST A LINEAR LINE OF STORMS MOVING FROM NORTHERN INDIANA INTO SW LOWER
MI LATE MORNING/EARLY AFTERNOON...AND PROGRESSING EAST QUITE RAPIDLY. THIS LINE
OF STORMS WILL LIKELY BE PRE-FRONTAL WITH A MORE NARROW LINE OF CONVECTION
FOLLOWING FOR LATE IN THE AFTERNOON AND EARLY EVENING...MARKING THE ARRIVAL OF
THE COLD FRONT.
CHILLY TEMPS ON TUESDAY IN THE MIDST OF CAA WILL MAKE FOR A RATHER
FALL-LIKE DAY. GUSTY WINDS ARE FORECAST TO BE 20 TO 30 MPH OR
PERHAPS GREATER AT TIMES...MAKING IT FEEL EVEN COLDER THAN THE
50S. CONDITIONS SLOWLY IMPROVE WEDNESDAY AND THURSDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 320 AM EDT MON MAY 11 2015
EXTENDED PERIOD LOOKS TO FEATURE NEAR TO ABOVE NORMAL TEMPERATURES
AND POTENTIALLY WET WEATHER. THE UPPER PATTERN WILL START WITH
RIDGING IN PLACE MID WEEK...WHICH WILL TREND TO A DEEP SOUTHWEST
FLOW LATE IN THE WORK WEEK AND INTO NEXT WEEKEND.
TWO MAIN WEATHER FEATURES TO KEEP AN EYE ON. FIRST IS A SHORTWAVE
THAT MOVES THROUGH THE REGION THURSDAY NIGHT AND FRIDAY. HAVE
SHOWERS IN THE FORECAST BOTH PERIODS. AT THIS POINT JUST CHANCE
POPS...BUT COULD SEE NEEDING TO BUMP THIS UP WITH TIME.
THE NEXT ITEM OF NOTE WILL BE OVER THE WEEKEND AS A WARM FRONT SETS
UP OVER THE GREAT LAKES AHEAD OF A LOW IN THE PLAINS. WE COULD SEE
PERIODS OF SHOWERS AND STORMS DURING THIS TIME FRAME.
HIGHS WILL START THE PERIOD IN THE 60S ON THURSDAY...BUT WARM INTO
THE 70S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 746 AM EDT MON MAY 11 2015
LIFR CONDITIONS ARE WIDESPREAD AT THE TAF SITES AT 12Z. A WARM
FRONT IS PUSHING NORTH FROM THE INTERSTATE 94 CORRIDOR WITH MUCH
IMPROVED CONDITIONS TO THE SOUTH OF IT...VFR. CONDITIONS SHOULD
CONTINUE TO IMPROVE THROUGH THE COURSE OF THE MORNING...AT LEAST
TO MVFR IF NOT VFR FOR A SHORT TIME AS THE WARM FRONT LIFTS
NORTHWARD.
THIS AFTERNOON...SHOWERS AND THUNDERSTORMS SHOULD MOVE INTO THE
AREA FROM THE SOUTHWEST. AT THIS POINT HAVE VCTS WORDING. THE
EARLY AFTERNOON SET OF TAFS MAY BE ABLE TO PROVIDE BETTER TIMING
IN REGARD TO THE PRECIPITATION. MOST LIKELY MVFR MUCH OF THE
AFTERNOON WITH CEILINGS AND POTENTIALLY VISIBILITIES.
THE SHOWERS...STORMS AND POOR AVIATION CONDITIONS SHOULD SWEEP
EAST THIS EVENING. THERE IS A CHANCE THAT MVFR CEILINGS COULD
REDEVELOP OVERNIGHT...BUT KEPT THINGS VFR AT THIS POINT.
&&
.MARINE...
ISSUED AT 1115 AM EDT MON MAY 11 2015
LOOKING AT WEB CAMS FOG DOES NOT SEEM TO BE MUCH OF AN ISSUE OVER
THE NEAR SHORE SO I DISCONTINUED THE DENSE FOG ADVISORY.
&&
.HYDROLOGY...
ISSUED AT 1222 PM EDT MON MAY 11 2015
ADDITIONAL RAINFALL AMOUNTS BETWEEN A QUARTER AND THREE QUARTERS OF
AN INCH WILL BE POSSIBLE MAINLY BEFORE MIDNIGHT TONIGHT. WE ARE
ISSUING ADVISORIES FOR THE SYCAMORE CREEK AT HOLT...WHICH SHOULD
CREST SHORTLY AFTER MIDNIGHT TONIGHT. CONFIDENCE IS HIGH THAT IT
WILL REMAIN BELOW FLOOD STAGE.
AFTER TONIGHT DRY CONDITIONS SHOULD PREVAIL UNTIL THURSDAY...WHEN
RAIN SHOWERS RETURN TO THE AREA. THIS SHOULD GIVE RIVER LEVELS
SOME TIME TO SUBSIDE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...TJT
MARINE...WDM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
340 PM EDT MON MAY 11 2015
.SYNOPSIS...
AFTERNOON SHOWERS AND THUNDERSTORMS TODAY AND AGAIN ON TUESDAY
WILL PRECEDE A COLD FRONT FRONT TUESDAY NIGHT. LESS HUMID AIR
ARRIVES ON WEDNESDAY AND SHOULD LAST INTO THURSDAY AS HIGH
PRESSURE MOVES OVERHEAD. THE LATTER PART OF THE WEEK AND WEEKEND
WILL FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM
CHANCES AS THE HIGH MOVES OFF THE COAST.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 330 PM MONDAY...VERY INTERESTING WEATHER DAY FOR MESOSCALE
FEATURES ONGOING ACROSS THE CWA. FIRST...CONVECTION HAS BLOSSOMED
ACROSS THE SOUTHERN AND EASTERN TIER AS EXPECTED...AND DEPICTED WELL
BY THE HRRR. A WEAK SURFACE TROUGH LIFTING NE THROUGH THE CWA...AS
WELL AS THE STRONG SEA BREEZE BOUNDARY PUSHING NW...ARE SERVING AS
FOCI FOR CONVECTION. THE ENVIRONMENT IS QUITE UNSTABLE...WITH UPR
60S AND LOW 70S DEWPOINTS LEFT IN THE WAKE OF TROPICAL STORM ANA
PROVIDING FUEL FOR 2000-3000 J/KG OF SBCAPE. LOW-LEVEL LAPSE RATES
ARE QUITE STEEP...BUT THEY WEAKEN CONSIDERABLY ABOVE 600 MB. THIS IS
IMPORTANT BECAUSE THE -10 TO -30 C (HAIL GROWTH ZONE) IS ABOVE THAT
LAYER. THIS SUGGESTS THAT...WHILE CONVECTION WILL REMAIN SCATTERED
TO NUMEROUS THIS AFTN...SEVERE WILL BE UNLIKELY DUE TO MUCH WEAKER
UPDRAFTS IN THE HAIL ZONE AND LOTS OF MELTING OF HAIL ON THE WAY
DOWN. STILL...SPC HAS INCLUDED OUR AREA IN AN MCD (5%) FOR ISOLATED
SEVERE THANKS TO MERGING BOUNDARIES POSSIBLY PRODUCING A LARGE HAIL
STONE OR MARGINAL WIND GUST.
WILL CONTINUE CHC/LKLY POP THROUGH NIGHTFALL BUT A RAPID DECREASE IN
COVERAGE IS EXPECTED WITH LOSS OF HEATING. A RESIDUAL LAYER OF
ELEVATED INSTABILITY IS PROGGED IN SOUNDINGS TO PERSIST WELL AFTER
DARK...SO ALTHOUGH THE HRRR SHOWS NO PRECIP AFTER MIDNIGHT...HAVE
OPTED TO KEEP SCHC/ISO SHOWERS THROUGH THE OVERNIGHT.
THE OTHER INTERESTING FEATURE TONIGHT HAS BEEN SEA FOG WHICH
DEVELOPED SOMEWHAT SURPRISINGLY THIS AFTN AND ADVECTED INTO THE
GRAND STRAND AND BRUNSWICK COUNTY. WE ARE BEYOND THE
CLIMATOLOGICALLY FAVORED SEASON FOR SEA FOG...AND THE LOCAL DECISION
TREE SUGGESTS VSBYS SHOULD BE UNRESTRICTED. YET...SEA FOG DID
DEVELOP AND BOTH THE HORRY AND BRUNSWICK COUNTY COASTS ARE "SOCKED
IN` AS OF THIS WRITING. IT IS BELIEVED THAT UPWELLING FROM LONG
DURATION OFFSHORE WINDS ON THE BACKSIDE OF RECENTLY-DEPARTED
TROPICAL STORM ANA COOLED THE SHELF WATERS ENOUGH TO PRODUCE THE
REQUIRED AIR-TO-OCEAN TEMP GRADIENT, THIS COMBINED WITH THE SW FLOW
TO CREATE LONG ENOUGH PARCEL RESIDENCE TIMES FOR SATURATION AND SEA
FOG. CERTAINLY AN INTERESTING SITUATION AND ONE FROM WHICH WE CAN
LEARN! STILL EXPECT VISIBILITY TO IMPROVE IN THE NEXT HOUR OR TWO AS
CONDITIONS ARE FAR FROM IDEAL FOR PERSISTENT SEA FOG.
MINS TONIGHT WILL BE HELD ABOVE CLIMO THANKS TO CONTINUED SW RETURN
FLOW...AND LOWS WILL DROP TO A DEGREE OR TWO EITHER SIDE OF
70...WARMEST AT THE COAST. GUIDANCE IS SUGGESTING STRATUS
DEVELOPMENT TONIGHT...AND IN THIS MOIST COLUMN IT IS DEFINITELY
PLAUSIBLE. HAVE SHOWN AN INCREASE IN CLOUD COVER AFTER
MIDNIGHT...WHICH WILL ALSO HELP TO KEEP MINS ELEVATED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...WEAK COLD FRONT WILL PUSH ACROSS THE AREA
LATE TUE NIGHT. AHEAD OF THE FRONT THE ENVIRONMENT APPEARS RIP FOR
DEVELOPMENT OF AFTERNOON CONVECTION. DEEP MOISTURE IS PRESENT WITH
FORECAST SOUNDINGS CARRYING PRECIPITABLE WATER VALUES OF 1.5 TO
1.6 INCH...WHICH IS WITHIN THE HIGHEST 10% FOR EARLY MAY.
SOUNDINGS CONTINUE TO ADVERTISE ML CAPE IN THE 2K TO 2.5K J/KG
RANGE WEST OF THE SEA BREEZE...WHICH WEST-SOUTHWEST FLOW SHOULD
KEEP CLOSER TO THE COAST. THE AFOREMENTIONED SEA BREEZE AND
PREFRONTAL TROUGH ARE LIKELY TO INITIATE AFTERNOON CONVECTION WITH
OUTFLOW DEVELOPING ADDITIONAL STORMS. MUCH OF THE AREA REMAINS IN
THE SPC DAY 2 OUTLOOK MARGINAL AREA AND FORECAST SOUNDINGS DO
SUGGEST SOME POTENTIAL FOR ISOLATED STRONG TO SEVERE STORMS.
HOWEVER...ORGANIZED WIDESPREAD STRONG/SEVERE ACTIVITY IS NOT
LIKELY. SHEAR IS NOT PARTICULARLY STRONG BUT LIFTED INDEX VALUES
ARE -5C TO -6C AND FAIRLY STRONG UPDRAFTS SHOULD BE POSSIBLE.
FREEZING LEVEL AROUND 13K FT LIKELY RULES OUT SIZABLE HAIL SO THE
MAIN THREAT WOULD BE ISOLATED DAMAGING WIND GUSTS.
COLD FRONT PUSHES ACROSS THE AREA TUE NIGHT WITH MUCH DRIER AIR MASS
BUILDING IN BEHIND IT. PRECIPITABLE WATER VALUES DROP OVER AN INCH
TUE INTO WED. DEEP NORTHWEST FLOW/MID LEVEL SUBSIDENCE WILL KEEP
SKIES CLEAR WED AFTERNOON. THE ONLY CAVEAT WILL BE ACROSS THE
COASTAL SC COUNTIES. THERE IS A WEAK SHORTWAVE CROSSING SC...WHICH
DOES HELP PUSH THE FRONT THROUGH...BUT THIS SHORTWAVE COULD TAKE A
BIT LONGER TO PUSH OFF THE SC COAST. IF THAT HAPPENS CLOUDS COULD
LINGER ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA. AT THIS POINT
DO NOT THINK PRECIP WILL LINGER INTO WED BUT WILL CARRY A NON-ZERO
POP FOR THE MORNING HOURS.
TEMPS WELL ABOVE CLIMO TUE WILL COOL OFF QUITE A BIT WED BUT HIGHS
STILL END UP RIGHT AROUND CLIMO...SHOWING JUST HOW WARM TUE IS GOING
TO BE. LOWS ABOVE CLIMO TUE NIGHT WILL BE NEAR TO SLIGHTLY BELOW
CLIMO WED NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 AM SUNDAY... MID LEVEL RIDGE OVERHEAD THURSDAY WHILE SURFACE
HIGH REMAINS TO OUR NORTH. LIKE WEDNESDAY WE EXPECT ANOTHER SUNNY
AND SEASONABLE DAY WITH FAIRLY LOW HUMIDITY. THIS WILL CHANGE
THURSDAY NIGHT INTO FRIDAY AS BOTH MOVE EASTWARD. THE WARMING WILL
BE RATHER GENTLE BUT THE HUMIDITY CREEPING UP MORE NOTICEABLE. THE
WEEKEND SHOULD THUS BRING FAIRLY SEASONABLE WARMTH AND HUMIDITY BUT
ALSO AT LEAST A SCATTERING OF MAINLY DIURNAL CONVECTION.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE HRRR MODEL SEEMS TO THINK WE WILL HAVE QUITE A BIT
OF CONVECTION THIS AFTERNOON...PARTICULARLY IN SOUTH CAROLINA. THERE
IS SOME SUBSIDENCE AROUND THE REMNANTS OF ANA...BUT THAT WILL BE
WANING THROUGH THE AFTERNOON HOURS SO SOME CONVECTION IS
EXPECTED...BUT WITH COVERAGE MAINLY CONFINED TO THE SEA BREEZE
BOUNDARY AND PLACES THAT RECEIVED FULL SUN TODAY. TONIGHT...MODELS
DO NOT SEEM TO THINK WE WILL SEE ANY FOG...BUT WITH ALL THE RAIN
THAT FELL ALONG THE COAST...EXPECT POSSIBLY SOME MVFR
FOG...ESPECIALLY HORRY AND BRUNSWICK COUNTIES. HOWEVER...RESIDUAL
WINDS AND LOW-LEVEL MOISTURE MAY DRIVE A STRATUS LAYER INSTEAD OF
FOG...AND HAVE SHOWN IFR IN ALL TAFS FOR LOW OVC. TUESDAY...CHANCES
FOR CONVECTION WILL INCREASE NEAR THE END OF THE FORECAST PERIOD
WITH A COLD FRONT.
EXTENDED OUTLOOK...SCATTERED SHOWERS POSSIBLE TUE EVENING AND AGAIN
ON FRIDAY. OTHERWISE EXPECT VFR..
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM MONDAY...ALL HEADLINES HAVE DROPPED FROM EARLIER TODAY
AS CONDITIONS HAVE IMPROVED ACROSS THE COASTAL WATERS. RESIDUAL
LARGE WAVES AND GUSTY WINDS FROM TROPICAL STORM ANA HAVE SHIFTED
WELL NE OF THE WATERS...WHICH ARE NOW UNDER THE INFLUENCE OF RETURN
SW FLOW. THIS WILL CONTINUE THROUGH TONIGHT...WITH FAIRLY STEADY 10-
15 KT SW WINDS...ALTHOUGH A FEW GUSTS TO 20 KTS WILL BE POSSIBLE
THROUGH THIS AFTN...ESPECIALLY ALONG THE SEA BREEZE IN THE NEAR
SHORE WATERS. SEAS WILL BE 2-4 FT...WITH A 6-7 SECOND PERIOD WAVE
PREDOMINANT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...SOUTHWEST FLOW AHEAD OF A COLD FRONT WILL
INCREASE AS GRADIENT AHEAD OF THE FRONT TIGHTENS. SPEEDS PEAK AROUND
20 KT IN TUE AFTERNOON AND EVENING WITH SEAS RUNNING 3 TO 4 FT.
WINDS VEER TO WESTERLY LATE TUE NIGHT AS THE FRONT CROSSES THE
WATERS. WEAK HIGH PRESSURE BUILDING IN BEHIND THE FRONT LIMITS THE
STRENGTH OF THE GRADIENT AND DEVELOPING OFFSHORE FLOW WILL BE UNDER
15 KT EARLY WED. WINDS WILL QUICKLY VEER TO NORTHEAST FOR WED BUT
GRADIENT REMAINS ILL DEFINED AND SPEEDS STAY 15 KT WITH SEAS
RUNNING 2 TO 3 FT THROUGH THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM SUNDAY... THE HIGH LOCATED TO OUR NORTH DURING THE
SHORT TERM PROGRESSES EAST DURING THE LONG TERM. WINDS VEER FROM N
TO E EARLY IN THE PERIOD AND SHALL MORE OR LESS REMAIN SAVE FOR
PERHAPS A SLIGHT ADDITIONAL VEER TO SE BY FRIDAY. THERE WILL BE NO
APPRECIABLE SWELL ENERGY TO SPEAK OF SO THE FAIRLY MINOR WIND
WAVES WILL BE THE DOMINANT SEA STATE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...III
LONG TERM...MBB
AVIATION...JDW/DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 PM EDT MON MAY 11 2015
.SYNOPSIS...THE REMNANTS OF TROPICAL CYCLONE ANA WILL TRACK
NORTHEAST INTO VIRGINIA THIS AFTERNOON. A COLD FRONT WILL MOVE
THROUGH THE AREA TUESDAY AFTERNOON AND EVENING. COOL HIGH PRESSURE
WILL BUILD INTO THE AREA THROUGH MID-WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 315 PM MONDAY...
WEAKENING REMAINS OF TC ANA WILL CONTINUE TO MOVE NORTHEASTWARD INTO
SOUTHEAST VA THIS AFTERNOON AND EVENING WITH AN EXPECTED INCREASE IN
ACCELERATION AS SW FLOW ALOFT STRENGTHENS IN ADVANCE OF A MID/UPPER
LEVEL TROUGH MOVING NORTHEASTWARD INTO THE MID/UPPER VALLEY.
IN THE WAKE OF TC ANA EXITING THE AREA...MODERATE DESTABILIZATION OF
2000-2500 J/KG PER SPC MESOANALYSIS HAS DEVELOPED IN RESPONSE TO
STEEP LOW-LEVEL LAPSE RATES ATOP A SEASONABLY MOIST BOUNDARY LAYER
FEATURING BL DEWPOINTS IN THE UPPER 60S TO LOWER 70S. FORCING FOR
ASCENT THIS AFTERNOON AND EVENING LOOKS TO BE DRIVEN BY TWO SEPARATE
WEAK FEATURES...1)ALONG SHALLOW CONVERGENCE ATTENDANT TO A
DEVELOPING SURFACE TROUGH IN THE LEE OF THE MOUNTAINS AND 2) A WEAK
UPPER LEVEL DISTURBANCE OVER SW NC/SC.
INITIALLY...EXPECT CONVECTION TO BE CONFINED TO THE WESTERN PIEDMONT
AND SANDHILLS/SOUTHERN COASTAL PLAIN WHERE THE SUPPRESSIVE INFLUENCE
OF SUBSIDENCE ON THE WESTERN PERIPHERY OF TC ANA`S REMNANTS WILL NO
LESS. GIVEN WEAK FORCING...EXPECT CONVECTION TO BE LARGELY DIURNAL
IN NATURE...AND THUS EXPECT MUCH OF THE ACTIVITY TO DROP OFF QUICKLY
AFTER SUNSET. HOWEVER...THE LATEST HRRR SUGGEST INITIAL STORMS OUT
WEST COULD PERSIST THROUGH MIDNIGHT AS THEY WORK SLOWLY EASTWARD
INTO THE COASTAL PLAIN. HAVE EXTENDED SMALL CHANCE POPS THROUGH 05-
06Z. WRT TO SEVERE WX...WEAK DEEP LAYER SHEAR OF 10-15 KTS WILL
PRECLUDE A MORE ORGANIZED THREAT. HOWEVER...GIVEN MODERATE
INSTABILITY AND DCAPE ~1000J/KG CANNOT RULE OUT AN ISOLATED SEVERE
STORM CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE....ESPECIALLY IN
THE WEST IN PROXIMITY TO DRIER AIR.
UNDER PARTLY TO MOSTLY CLOUDY MID AND HIGH CLOUDS...EXPECT MILD
OVERNIGHT LOWS IN THE UPPER 60S TO NEAR 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 315 PM MONDAY...
MID AND UPPER LEVEL FLOW REALLY FLATTENS OUT...BECOMING WESTERLY ON
TUESDAY AS THE WELL REMOVED UPPER TROUGH TRAVERSE THE UPPER GREAT
LAKES/NEW ENGLAND. ATTENDANT SURFACE LOW TRACKING THROUGH SE CANADA
WILL DRAG A COLD FRONT THROUGH THE AREA BETWEEN 18Z TUESDAY IN THE
WEST TO 00 TO 03Z IN THE EAST. GUIDANCE SUGGESTS BL DEWPOINTS WILL
BE APT TO MIX OUT A BIT...ESPECIALLY OVER THE WESTERN PIEDMONT
TUESDAY AFTERNOON. THE WESTERLY COMPONENT ALOFT AND LACK OF SUPPORT
ALOFT WILL TEND TO SUPPRESS CONVECTION ACROSS A LARGE CHUNK OF THE
FORECAST WITH CONVECTION MOST APT TO FIRE ACROSS EASTERN PIEDMONT
AND COASTAL PLAIN(I-95 CORRIDOR)...WHERE LINGERING LOW-LEVEL
MOISTURE AND STRONG INSOLATION COULD SUPPORT MODERATE TO STRONG
DESTABILIZATION OF 2000-3000 J/KG OF SBCAPE. WRT TO SEVERE
POTENTIAL...DEEP LAYER SHEAR MAY BE MARGINALLY BETTER THAN TODAY...
BUT NOT BY MUCH...PARTICULARLY IN THE EAST. THUS A FEW STRONG TO
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING LOCALIZED WIND DAMAGE MAY
DEVELOP ACROSS THE EASTERN PIEDMONT/COASTAL PLAIN AREAS.
LOW-LEVEL THICKNESSES WILL BE MORE REPRESENTATIVE OF MID TO LATE
JUNE AS OPPOSED TO EARLY MAY. EXPECT HIGHS IN THE UPPER 80S TO LOWER
90S...WHICH WOULD BE THE FIRST TIME WE REACHED 90 DEGREES AT KRDU
AND KFAY.
SKIES SHOULD CLEAR OUT TUESDAY EVENING/NIGHT WITH CAA DRIVING
OVERNIGHT LOWS. LOWS RANGING FROM MID 50S NW TO LOWER 60S SE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE GREAT
LAKES WEDNESDAY THROUGH THURSDAY...BEFORE SHIFTING OFFSHORE THURSDAY
NIGHT INTO FRIDAY. AT THE SAME TIME...MID LEVEL RIDGING WILL BUILD
OVER THE AREA FROM THE EAST. MUCH COOLER AND DRIER AIR WILL FILTER
INTO THE REGION...RESULTING IN A PERIOD OF DRY WEATHER AND NEAR TO
SLIGHTLY BELOW NORMAL TEMPS.
AS THE SURFACE HIGH CONTINUES TO SHIFT OFFSHORE ON FRIDAY...MOISTURE
WILL BEGIN TO RECOVER ON THE BACK SIDE OF THE HIGH. HOWEVER...THE
MID LEVEL RIDGING WILL STICK AROUND FOR A WHILE LONGER WHICH MAY
PREVENT WIDESPREAD CONVECTION. AS OF NOW...IT APPEARS THE BEST
CHANCE OF A SHOWER OR STORM WILL BE ACROSS THE WESTERN PIEDMONT ON
FRIDAY AND SATURDAY...WITH CHANCES SPREADING EAST (AND INCREASING)
SUNDAY INTO MONDAY AS MOISTURE AND INSTABILITY INCREASES EVEN MORE.
TEMPS WILL GRADUALLY WARM EACH DAY...WITH HIGHS GENERALLY IN THE MID
80S AND OVERNIGHT LOWS IN THE MID 60S BY EARLY NEXT WEEK.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 130 PM MONDAY...
24-HR TAF PERIOD: AS ANA`S REMNANTS CONTINUES TO LIFT NORTHEAST...
AWAY FROM THE AREA...OUTSIDE OF ISOLATED TO WIDELY SCATTERED
CONVECTION...EXPECT PREDOMINATELY VFR CONDITIONS THIS AFTERNOON AND
EVENING. A STEADY 5 TO 10KT SWLY BREEZE OVERNIGHT IN ADVANCE OF A
COLD FRONT APPROACHING FROM THE WEST SHOULD PRECLUDE ANY FOG
DEVELOPMENT OVERNIGHT/EARLY TUESDAY MORNING. ADDITIONALLY...GIVEN
MOIST LOW-LEVELS COULD SEE SOME SUB-VFR STRATUS EARLY TUESDAY
MORNING...ESPECIALLY AT KFAY WHERE BETTER LOW-LEVEL MOISTURE IS
EXPECTED. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
ACCOMPANY A COLD FRONTAL PASSAGE THROUGH THE AREA
TUESDAY AFTERNOON...ESPECIALLY ALONG AND EAST OF RDU.
LOOKING AHEAD: EXPECT DRY VFR CONDITIONS TUESDAY NIGHT THROUGH
FRIDAY ASSOCIATED WITH COOL HIGH PRESSURE BUILDING OVER THE AREA.
THE HIGH WILL PUSH OFFSHORE ON FRIDAY. SOUTHERLY RETURN FLOW ON THE
WESTERN PERIPHERY OF THE HIGH WILL BRING AN INCREASE LIKELIHOOD OF
SUB-VFR CONDITIONS IN MORNING FOG AND/OR STRATUS ALONG WITH A
CHANCE OF MAINLY AFTERNOON SHOWERS AND STORMS LATE FRIDAY NIGHT
AND INTO THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT/CBL
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...KRD
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
122 PM EDT MON MAY 11 2015
.SYNOPSIS...
UNSETTLED WEATHER MONDAY AND TUESDAY WILL PRECEDE A TUESDAY NIGHT
COLD FRONT. LESS HUMID AIR ARRIVES BY WEDNESDAY AND SHOULD LAST
INTO THURSDAY. THE LATTER PART OF THE WEEK AND WEEKEND WILL
FEATURE A GRADUAL INCREASE IN HUMIDITY AND THUNDERSTORM CHANCES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...FOR THE FIRST TIME IN WHAT SEEMS LIKE
AGES...TROPICAL STORM ANA IS NOT THE MAIN FORECAST CHALLENGE FOR THE
PERIOD. WHILE ANA REMAINS IN THE GENERAL VICINITY AS A TROPICAL
DEPRESSION LIFTING OFF INTO NE NORTH CAROLINA...HER SHOWERS AND
CLOUDS ARE CONFINED TO THE EXTREME NE PORTION OF THE CWA...AND THIS
WILL ERODE THROUGH LATE MORNING. AT THAT POINT ANA WILL FINALLY BE
DONE WITH THE WILMINGTON CWA.
BEHIND ANA...SURFACE RIDGE WILL BUILD INTO THE CWA CREATING A WARM
AND PARTLY SUNNY DAY - MORE SUN IN LOCATIONS WELL REMOVED FROM ANA -
BUT IN A STILL VERY MOIST ENVIRONMENT. TEMPS WILL SOAR QUICKLY THIS
MORNING THROUGH THE 70S AND INTO THE 80S...AND HIGHS THIS AFTN MAY
TOUCH 90 IN THE FAR SW ZONES...BUT ONLY INTO THE LOW 80S ALONG THE
COAST AS WELL AS IN THE NE ZONES. THIS SHOULD PROMOTE A SIGNIFICANT
RESULTANT SEA BREEZE BOUNDARY...AS WELL AS A PIEDMONT TROUGH. HIGH
RES GUIDANCE SUGGESTS THAT CONVECTION WILL RE-DEVELOP THIS AFTN AS A
WEAK SURFACE TROUGH LIFTS NE THROUGH THE CWA. WHILE SOME SUBSIDENCE
IS LIKELY BEHIND DEPARTING ANA...A VERY UNSTABLE AIRMASS (SBCAPE
NEAR 3000 J/KG) AND HIGH PWATS SHOULD PROMOTE SCATTERED TO MAYBE
WIDESPREAD CONVECTION LATE THIS AFTN...ESPECIALLY ACROSS WESTERN
ZONES. HEAVY RAINFALL IS THE MOST LIKELY THREAT...BUT SMALL HAIL
CANNOT BE RULED OUT THANKS TO SIGNIFICANT CAPE AS WELL IN THE -10 TO
-30 C HAIL GROWTH ZONE. FORTUNATELY...THE MOST WIDESPREAD ACTIVITY
IS EXPECTED IN PLACES THAT DID NOT RECEIVE THE TREMENDOUS RAINFALL
FROM ANA...SO FLOODING...WHILE STILL POSSIBLE...IS NOT EXPECTED TO
BE WIDESPREAD.
CONVECTION WILL WANE AFTER DARK WITH LOSS OF DIURNAL HEATING...BUT
RESIDUAL ELEVATED INSTABILITY COULD KEEP ISOLATED SHOWERS GOING
THROUGH THE NIGHT AND HAVE MAINTAINED SCHC POP THROUGH THE OVERNIGHT
HOURS. TEMPS TONIGHT WILL REMAIN QUITE WARM ON CONTINUED SW
FLOW...FALLING ONLY TO A DEGREE OR TWO EITHER SIDE OF 70.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM SUNDAY... A WARM AND HUMID AFTERNOON ON TUESDAY WILL LEAD
TO THE DEVELOPMENT OF 2000-2500 J/KG OF MLCAPE FOCUSED MAINLY OVER
NEERN ZONES INCLUDING CAPE FEAR REGION. THE LFC WILL BE AROUND KFT
AND WITH A HEALTHY BUT PINNED SEABREEZE AND WEAK SHORTWAVE WE SHOULD
BE ABLE TO LIFT A FEW PARCELS TO THAT LEVEL. THUS EXPECT SOME
HEALTHY UPDRAFTS MAINLY OVER EASTERN HALF OF THE CWA THOUGH AN
INLAND TROUGH COULD TOUCH OFF A FEW STORMS FURTHER WEST AS WELL. A
LITTLE BIT OF DIRECTIONAL SHEAR IN THE LOW LEVELS BUT DEEP LAYER
SHEAR A BIT TOO WEAK FOR ORGANIZED CONVECTION. HOWEVER GIVEN THE
STRENGTH OF THE INSTABILITY AND FAIRLY HIGH LIFTED INDICES A FEW
STORMS SEEM CAPABLE OF PULSING TO SEVERE LIMITS ESPECIALLY IF THERE
IS MORE SUNSHINE THAN ANTICIPATED...WHICH IS A DISTINCT POSSIBILITY
AS THE WESTERLY MID LEVEL DRYING LOOKS UNDERDONE IN FORECAST
SOUNDINGS. THE PREFRONTAL TROUGH GETS OVERTAKEN BY A COLD FRONT
TUESDAY NIGHT AS IT PUSHES THROUGH THE REGION. AND WHILE THE COOLING
BEHIND THIS BOUNDARY WILL ONLY BE MODEST THE DROP IN HUMIDITY WILL
BE MORE PRONOUNCED. THE MID AND UPPER LEVEL DRYING IS SIMILARLY
STRONG SO EXPECT A SEASONABLE, SUNNY, AND COMFORTABLY NON-HUMID
AFTERNOON.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM SUNDAY... MID LEVEL RIDGE OVERHEAD THURSDAY WHILE SURFACE
HIGH REMAINS TO OUR NORTH. LIKE WEDNESDAY WE EXPECT ANOTHER SUNNY
AND SEASONABLE DAY WITH FAIRLY LOW HUMIDITY. THIS WILL CHANGE
THURSDAY NIGHT INTO FRIDAY AS BOTH MOVE EASTWARD. THE WARMING WILL
BE RATHER GENTLE BUT THE HUMIDITY CREEPING UP MORE NOTICEABLE. THE
WEEKEND SHOULD THUS BRING FAIRLY SEASONABLE WARMTH AND HUMIDITY BUT
ALSO AT LEAST A SCATTERING OF MAINLY DIURNAL CONVECTION.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE HRRR MODEL SEEMS TO THINK WE WILL HAVE QUITE A BIT
OF CONVECTION THIS AFTERNOON...PARTICULARLY IN SOUTH CAROLINA. THERE
IS SOME SUBSIDENCE AROUND THE REMNANTS OF ANA...BUT THAT WILL BE
WANING THROUGH THE AFTERNOON HOURS SO SOME CONVECTION IS
EXPECTED...BUT WITH COVERAGE MAINLY CONFINED TO THE SEA BREEZE
BOUNDARY AND PLACES THAT RECEIVED FULL SUN TODAY. TONIGHT...MODELS
DO NOT SEEM TO THINK WE WILL SEE ANY FOG...BUT WITH ALL THE RAIN
THAT FELL ALONG THE COAST...EXPECT POSSIBLY SOME MVFR
FOG...ESPECIALLY HORRY AND BRUNSWICK COUNTIES. HOWEVER...RESIDUAL
WINDS AND LOW-LEVEL MOISTURE MAY DRIVE A STRATUS LAYER INSTEAD OF
FOG...AND HAVE SHOWN IFR IN ALL TAFS FOR LOW OVC. TUESDAY...CHANCES
FOR CONVECTION WILL INCREASE NEAR THE END OF THE FORECAST PERIOD
WITH A COLD FRONT.
EXTENDED OUTLOOK...SCATTERED SHOWERS POSSIBLE TUE EVENING AND AGAIN
ON FRIDAY. OTHERWISE EXPECT VFR..
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...IMPROVING CONDITIONS ACROSS THE COASTAL
WATERS THIS MORNING AS TD ANA DEPARTS OFF TO THE NE. RESIDUAL HIGH
SEAS PERSIST ACROSS THE NC WATERS AND THE SCA REMAINS IN PLACE UNTIL
NOON TODAY. THE SCA FOR THE SC WATERS DROPPED AT 8AM. SEAS WILL
CONTINUE TO FALL AND WINDS WILL BECOME SWLY AT 10-15 KTS ACROSS ALL
THE WATERS THIS AFTN. THESE WINDS WILL THEN PERSIST THROUGH THE END
OF THE PERIOD...CREATING SEAS OF 2-4 FT TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SUNDAY...SOUTHWESTERLY PRE-FRONTAL FLOW ON TUESDAY
WITH AN INLAND PIEDMONT TROUGH AND A FAIRLY PINNED SEA BREEZE. THE
GRADIENT MAY BECOME RATHER PINCHED ESPECIALLY TUESDAY NIGHT AT
WHICH TIME A COLD FRONT WILL OVERTAKE THE TROUGH AND PUSH ACROSS
THE WATERS. CURRENTLY IT APPEARS THAT THE RAPIDITY THAT THIS ALL
OCCURS PAIRED WITH THE MINIMAL ONSHORE FLOW COMPONENT THERE SHOULD
BE NO HEADLINES. BEHIND THE BOUNDARY A LIGHT NORTHERLY GRADIENT
WIND SETS UP AS HIGH PRESSURE REMAINS WELL REMOVED TO OUR NORTH.
WINDS BECOME QUITE LIGHT AND VARIABLE BY THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM SUNDAY... THE HIGH LOCATED TO OUR NORTH DURING THE SHORT
TERM PROGRESSES EAST DURING THE LONG TERM. WINDS VEER FROM N TO E
EARLY IN THE PERIOD AND SHALL MORE OR LESS REMAIN SAVE FOR PERHAPS A
SLIGHT ADDITIONAL VEER TO SE BY FRIDAY. THERE WILL BE NO APPRECIABLE
SWELL ENERGY TO SPEAK OF SO THE FAIRLY MINOR WIND WAVES WILL BE THE
DOMINANT SEA STATE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43/JDW
MARINE...JDW/MBB
AREA FORECAST DISCUSSION
NWS PORTLAND
215 PM PDT MON MAY 11 2015
.SYNOPSIS...AN UPPER LOW CENTERED WEST OF NEWPORT EARLY THIS
AFTERNOON WILL CONTINUE TO SLOWLY DRIFT SOUTH...THEN MOVE INLAND
INTO SOUTHERN OREGON TONIGHT AND TUESDAY. MOIST SOUTH FLOW ALOFT WILL
RESULT IN UNSETTLED CONDITIONS FOR THE NEXT COUPLE OF DAYS. A BAND OF
STEADIER RAIN ALONG THE CASCADES THIS AFTERNOON IS EXPECTED TO
ENHANCE AND PIVOT NORTH TO NORTHWEST THIS EVENING. THE LOW WILL
MOVE INTO EASTERN OREGON AND EASTERN WASHINGTON TUESDAY NIGHT AND
WEDNESDAY AS ANOTHER LOW DROPS SOUTH OFF THE COAST AND SLOWLY MOVES
INTO CALIFORNIA DURING THE LATTER PART OF THE WEEK AND NEXT WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH THURSDAY...EARLY-AFTERNOON WATER VAPOR
LOOP SHOWS AN UPPER LEVEL LOW CENTERED WEST OF KONP AND SINKING TO
THE S. CONSIDERABLE MOISTURE IN WATER VAPOR FOCUSED OVER THE
CASCADES. ALSO LOOKS LIKE A SHORT-WAVE ROTATING INTO SOUTH-CENTRAL
OREGON...WHICH HAS RESULTED IN THUNDERSTORM ACTIVITY IN SWRN LAKE
COUNTY. KRTX DUAL-POL DOPPLER RADAR SHOWS THE BULK OF THE PRECIP
ECHOES ALONG THE CENTRAL AND NORTH OREGON CASCADES INTO ERN CLARK AND
COWLITZ COUNTIES IN SW WA. 12Z MODEL RUNS AGREE THAT THE UPPER LOW
WILL CONTINUE TO DRIFT SOUTH THIS EVENING...THEN MOVE INLAND OVER NW
CALIFORNIA BY 12Z TUE. MODELS ALSO SUGGEST THAT PRECIP WILL BECOME
MORE ENHANCED LATE THIS AFTERNOON DUE TO SE-S MID-LEVEL FLOW.
HOWEVER...MODELS DO NOT SEEM TO AGREE ON QPF. GFS SHOW MUCH MORE
RAINFALL TONIGHT THAN THE NAM OR ECMWF. THE NAM PIVOTS THE DEVELPING
DEFORMATION BAND FURTHER N THAN THE GLOBAL MODELS. THE 19Z HRRR RUN
HAS THE DEFORMATION BAND DEVELOPING A FEW HOURS LATER THAN THE
EARLIER MORNING RUNS INDICATED...AND SETTLING OVER SRN WA DOWN TO
ABOUT A KTKM-KSLE-MT. HOOD LINE BY 07Z TUE. HIGH CONFIDENCE IN
WETTING RAIN AMOUNTS...ONE-QUARTER INCH OR GREATER...ACROSS PORTIONS
OF THE CWA TONIGHT AND TUE MORNING. LOWER CONFIDENCE ON EXACT
LOCATION OF THE DEFORMATION BAND.
CONVECTIVE CHANCES TODAY DO NOT LOOK ALL THAT IMPRESSIVE. NAM
SOUNDINGS FOR KPDX SHOW AN ISOTHERMAL LAYER THIS AFERNOON BETWEEN 850
AND 700 MB. MODEL SOUNDING FOR A POINT IN THE CASCADES HAS THE SAME
GENERAL PROFILE...BUT DOES HAVE AN LI NEAR 0C THIS AFTERNOON.
INCREASED POPS IN THE 00-06Z TUE TIME FRAME...ESPECIALLY IN THE
CASCADES AND NORTHERN ZONES. THE DEFORMATION ZONE PERSISTS TUE
MORNING. THE NAM ROTATES IT ACROSS SW WA TO THE N OREGON COAST BY 18Z
TUE...SIMILAR TO THE ECMWF. IT FINALLY BREAKS UP TUE AFTERNOON. THE
MODELS SHOW A DECENT AMOUNT OF CYCLONIC LOW LEVEL ONSHORE FLOW
DEVELOPING BELOW THIS BAND AS WELL. CASCADE MODEL SOUNDINGS SUGGEST A
LIT MORE SUPPORT FOR CONVECTION TUE AFTERNOON. NAM SOUNDING GIVES
200-250 J/KG CAPE 00Z WED...WHILE THE GFS HAS NEAR-ZERO LI VALUES. .
THE REMAINS OF THE UPPER LOW LIFT OUT INTO SE WASHINGTON TUE NIGHT
AND INTO NE WA BY WED AFTERNOON. ANY REMAINING DEFORMATION WILL
LINGER OVER THE S WA CASCADES WED MORNING AND HAVE THE HIGHEST POPS
THERE. DECIDED TO INCLUDE A MENTION OF THUNDERSTORMS FOR THE CENTRAL
AND N OREGON CASCADES BEGINNING WED AFTERNOON. MODEL SOUNDINGS SHOW A
DEFINITE CAP AROUND 700 MB WED MORNING...BUT BY 21Z THE CAP IS GONE
WITH CAPE OVER 100 J/KG. AT 00Z THU MODEL CAPE HAS INCREASED TO
NEARLY 300 J/KG WITH LI -1C. THINK THE S WA CASCADES WILL HAVE TOO
MUCH CLOUD COVER AS THE DEFORMATION BAND SLOWLY DRIFTS N. MUCH MORE
IMPRESSIVE CONVECTIVE ENVIRONMENT POSSIBLE THU. PRIMARY UPPER LOW
SETTLES OFF THE N CALIFORNIA COAST THU AFTERNOON...WHICH SETS UP
UNSTABLE SE-S FLOW OVER THE FORECAST AREA. NAM SOUNDING NEAR SANTIAM
PASS HAS NEARLY 550 J/KG CAPE WITH AN LI OF -2C 00Z FRI. GFS EVEN
MORE IMPRESSIVE WITH CONVECTIVE PARAMETERS THU. WEISHAAR
.LONG TERM...THURSDAY NIGHT THROUGH SUNDAY...BY THURSDAY NIGHT A
BROAD UPPER LOW PRESSURE WILL CONTINUE A GENERAL TRACK SOUTHWARD
ALONG THE CALIFORNIA COAST. MODEL GUIDANCE THIS AFTERNOON IS COMING
INTO GOOD AGREEMENT WITH THE GENERAL PATTERN AND EXPECT SHOWERS
LINGERING THURSDAY NIGHT AND ALSO ON FRIDAY...WITH THE BEST CHANCES
TOWARDS THE CASCADES. MIGHT ALSO BE ENOUGH INSTABILITY TO GET A FEW
THUNDERSTORMS NEAR THE CASCADES FROM MT HOOD SOUTHWARD ON FRIDAY.
THIS UPPER LOW CONTINUES EASTWARD WITH THE NEXT UPPER LOW PRESSURE
SYSTEM MOVING TOWARDS THE REGION OVER THE WEEKEND...MAINTAINING
ONSHORE FLOW ALOFT AND THE POTENTIAL FOR CONTINUING SHOWERS THIS
WEEKEND. OVERALL...NOT MUCH CHANGE TO THE OVERALL PATTERN THROUGH
THE EXTENDED PERIOD WITH TEMPERATURES NEAR SEASONAL NORMS AND SHOWER
CHANCES CONTINUING. CULLEN
&&
.AVIATION...CIGS HAVE LIFTED TO PRIMARILY VFR. SHOWERS ARE STAYING
NORTH OF TAF SITES...WHICH IS HELPING KEEP CIGS VFR. MODELS
SUGGEST THAT THE BAND OF RAIN TO THE NORTH WILL MIGRATE
SOUTHWARD...REACHING NORTHERN TAF SITES AROUND 04Z. AT THIS
TIME CIGS SHOULD DROP TO MVFR AT NORTHERN WILLAMETTE VALLEY TAF
SITES AND KAST. VIS MAY DROP TO MVFR WITH HEAVIER SHOWERS. THIS
BAND OF RAIN SHOULD REMAIN NORTH OF KSLE OVERNIGHT...BUT MODELS
STILL SUGGEST CIGS AT KSLE AND KEUG WILL DROP TO MVFR AROUND
04Z...THOUGH CONFIDENCE IS LOWER. KONP MAY STAY VFR LONGER
OVERNIGHT WITH CONTINUED OFFSHORE FLOW UNTIL RAIN MOVES IN AROUND
09-12Z...WHICH WILL CAUSE CIGS AND POSSIBLY VIS TO DROP TO MVFR.
CIGS ACROSS THE AREA EXPECTED TO REMAIN MVFR THROUGH TUESDAY
MORNING.
KPDX AND APPROACHES...VFR CONDITIONS TO CONTINUE THIS AFTERNOON
UNTIL AROUND 12/04Z WHEN MODERATE RAIN MOVES OVER TERMINAL. CIGS
TO REMAIN MVFR THROUGH TUESDAY MORNING. VIS MAY DROP TO MVFR
OCCASIONALLY WITH HEAVIER SHOWERS. -MCCOY
&&
.MARINE...HIGH PRESSURE OVER THE NE PACIFIC IS KEEPING CONDITIONS
FAIRLY BENIGN. SEAS SHOULD REMAIN AROUND 5 TO 7 FT THROUGH
TUESDAY WITH NORTHWESTERLY WINDS STAYING BELOW 20 KT. A WEAK LOW
PRESSURE SYSTEM MOVES THROUGH ON WEDNESDAY...BUILDING SEAS TO
AROUND 8 FT...BUT WINDS EXPECTED TO REMAIN BELOW 20 KT. SEAS FALL
BACK DOWN TO 5 TO 6 FT BY THE END OF THIS WEEK WITH THE RETURN OF
NORTHWESTERLY WINDS AS HIGH PRESSURE BUILDS BACK OVER THE WATERS.
-MCCOY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
152 PM EDT MON MAY 11 2015
.SYNOPSIS...
THE REMNANTS OF ANA WILL CONTINUE TO MOVE NORTHEAST ALONG THE
ATLANTIC COAST TONIGHT. ON TUESDAY...A WEAK COLD FRONT WILL CROSS
OUR AREA BEFORE STRONG HIGH PRESSURE BUILDS IN FROM THE NORTH AND
REMAINS THROUGH THURSDAY. ANOTHER COLD FRONT WILL APPROACH THE REGION
ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 145 PM EDT MONDAY...NO SIGNIFICANT CHANGES TO THE FCST WITH
THIS UPDATE. DID TWEAK POPS/SKY/TEMPS A BIT TO BETTER REFLECT
RECENT RADAR/OB TRENDS AS CONVECTION HAS INITIATED ACROSS PORTIONS
OF THE NC HIGH TERRAIN. OTHERWISE...FULL FCST DISCUSSION TO FOLLOW
WITHIN THE HOUR.
PREVIOUS DISCUSSION...
AS OF 310 AM...ISOLATED CONVECTION CONTINUES TO FIRE ALONG A
GRADIENT IN MUCAPE SOUTH OF THE I-85 CORRIDOR THIS MORNING. WILL
CONTINUE TO RETAIN 20 POPS IN THIS AREA THROUGH ABOUT DAYBREAK.
OTHERWISE...ATTENTION TURNS TO THE CONVECTIVE POTENTIAL FOR LATER
TODAY. DEWPOINTS IN THE MID/UPPER 60S ARE EXPECTED TO COMBINE WITH
STEEP LOW LEVEL LAPSE RATES TO YIELD SOME OF THE MORE ROBUST CAPE
VALUES WE/VE SEEN IN RECENT DAYS...WITH A CONSENSUS OF DETERMINISTIC
AND ENSEMBLE GUIDANCE CLEARLY SUPPORTING SBCAPE IN THE 2000-2500
J/KG RANGE THIS AFTERNOON. IN ADDITION...MOISTURE WILL BE MORE
PLENTIFUL THROUGH A DEEP LAYER...WITH PWATS OF AROUND 1.5...OR ABOUT
2 STANDARD DEVS ABOVE CLIMO...EXPECTED ACROSS THE PIEDMONT THIS PM.
WHAT WILL BE LACKING IS AN OBVIOUS SOURCE OF ORGANIZED LIFT.
HOWEVER...IT IS INTERESTING THAT SOME OF THE CONVECTION-ALLOWING
MODELS...AND EVEN THE NAM APPEAR TO BE HIGHLIGHTING A LOW LEVEL
CONVERGENCE AXIS ACROSS EAST TENN AND NORTH GA. THE HRRR AND NSSL
WRF LIGHT THIS AREA UP...SUGGESTING (AT LEAST) NUMEROUS CONVECTIVE
COVERAGE BY EARLY/MID AFTERNOON...WHICH WOULD PUSH INTO OUR AREA
BY MID/LATE AFTERNOON. LIKELY POPS WILL BE CARRIED OVER THE
MTNS...WHERE DIFF HEATING STILL APPEARS TO BE THE BEST BET FOR
INITIATING CONVECTION. HOWEVER...POPS HAVE ALSO BEEN BUMPED TO 50
PERCENT ACROSS MUCH OF THE REMAINDER OF THE WESTERN HALF OF THE
FORECAST AREA. IF THE MESOSCALE MODELS HAVE THE RIGHT IDEA...
THIS WILL BE TOO LOW. WHILE PROFILES ARE GENERALLY MOIST...STEEP
LOW LEVEL LAPSE RATES/A HOT BOUNDARY LAYER SHOULD YIELD
DOWNDRAFT CAPE IN THE 500-1000 J/KG RANGE THIS AFTERNOON...WHICH
COULD COMBINE WITH WEAK SHEAR AND WATER LOADING TO YIELD A WET
MICROBURST THREAT WITH SOME OF THE STRONGER UPDRAFTS. WHILE DEEP
LAYER SHEAR IS WEAK...THERE COULD BE JUST ENOUGH SHEAR OVER COLD
POOL DEPTH TO PROMOTE SOME DEGREE OF LIMITED UPSCALE ORGANIZATION...
WHICH WOULD RESULT IN A MORE ORGANIZED DOWNBURST THREAT.
COVERAGE OF CONVECTION WILL GRADUALLY DIMINISH TONIGHT. A COLD FRONT
WILL APPROACH THE SOUTHERN APPALACHIANS FROM THE TENN VALLEY
OVERNIGHT. HOWEVER...THERE IS A DEFINITIVE MODEL CONSENSUS
SUGGESTING THAT ANY ASSOCIATED CONVECTION WILL BE DIMINISHING AS THE
BOUNDARY NUDGES INTO THE FORECAST AREA TOWARD DAYBREAK. TOKEN SMALL
CHANCE POPS WILL NEVERTHELESS BE RETAINED. TEMPERATURES WILL REMAIN
A SOLID 10 DEGREES ABOVE CLIMO THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
200 PM EDT MONDAY...SHORT TERM LOOKS TO BE RATHER TRANQUIL AS
COLD FRONT SETTLES WELL SOUTH OF THE AREA AS DRY CP HIGH PRESSURE
BUILDS IN FROM THE NW. AN UPPER RIDGE IS FORECAST TO BUILD ACROSS
THE SE U.S. WED THROUGH THU. DEWPOINTS ARE FORECAST TO DROP WELL
INTO THE 40S ON WED WITH ONLY A SLOW RECOVERY ON THU INTO THE 50S AS
THE SURFACE HIGH MOVES TO THE COAST. HENCE...MOSTLY CLEAR CONDITIONS
WILL BE IN THE FORECAST TUE NIGHT THROUGH THURSDAY WITH TEMPS
LOWERING TO NEAR SEASONAL VALUES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
215 PM EDT MONDAY...THE MEDIUM RANGE WILL BE UNSETTLED AS THE
AXIS OF THE UPPER HIGH INITIALLY MOVES EAST OF THE AREA ALONG THE
COAST. ALSO AS THE SURFACE MOVES INTO THE WESTERN ATLANTIC...RETURN FLOW
WILL TAP INTO GULF MOISTURE. MODEL TIME HEIGHTS INDICATE THAT DEEP
LAYER MOISTURE WILL ADVECT INTO THE WESTERN CAROLINAS AND NE GA
DURING FRIDAY AND REMAIN IN PLACE INTO THE FIRST PART OF NEXT WEEK.
WITH THE PERSISTENT DEEP MOISTURE IN PLACE...MODELS AND ESPECIALLY
THE GFS RESPOND WITH CONSIDERABLE QPF. INSTABILITY IS FORECAST TO BE
ON THE LOW SIDE INITIALLY ON FRI AS PERHAPS IN-SITU CAD DEVELOPS.
MODELS INDICATE THAT INSTABILITY WILL THEN GRADUALLY INCREASE EACH
AFTERNOON FROM SAT THROUGH MON.THE EC SHOWS MORE OF A DIURNAL CYCLE
TO THE QPF OVER THE WEEKEND WHICH LOOKS MORE REASONABLE AND WILL
TREND FROECAST THAT WAY. WILL RAMP UP POPS TO CHANCE FRIDAY
AFTERNOON. GUIDANCE THEN SUGGESTS THAT SOME LIKLEY POPS WILL BE
NEEDED SAT AND SUN AFTERNOONS OVER THE MOUNTAINS. ON
MONDAY...COVERAGE OF SHOWERS AND THUNDERSTORMS MAY BECOME LESS IF UPPER
RIDGE BUILDS BACK OVER THE REGION PER THE GFS. INCREASED CLOUD COVER
WILL KEEP TEMPS IN CHECK INITIALLY WITH A REDUCED DIURNAL RANGE. MAX
TEMPS ARE EXPECTED TO BE BELOW CLIMO FRI...THEN INCREASE TO AROUND
CLIMO SAT AND THEN ABOVE SUN AND MON AS UPPER RIDGE REESTABLISHES
ITSELF.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...PREDOMINATELY VFR THROUGH THE PERIOD WITH THE EXCEPTION OF
POSSIBLE MVFR RESTRICTIONS RESULTING FROM AFTERNOON CONVECTION.
INITIALIZED TAF WITH MODEST SW WINDS UNDER FEW LLV CU AS LAPSE RATES
CONTINUE TO STEEPEN WITH HEATING. FURTHER CU FIELD EXPANSION IS
EXPECTED THROUGH THE AFTERNOON...THUS PREVAIL LLV VFR CIGS AT 20Z
WITH A 4HR TEMPO FOR DEVELOPING AIRMASS TSRA YIELDING VRB 20KT
GUSTS. ALL WX IS REMOVED NLT 01Z WITH MID LEVEL CLOUDS PREVAILING
UNDER BKN HIGH LEVEL CIGS WITH LIGHT WINDS THROUGH THE OVERNIGHT.
WINDS WILL INCREASE LATE IN THE PERIOD AS FRONTAL AXIS APPROACHES
FROM THE WEST...HOWEVER REMAINING SW WITH NO GUSTING.
ELSEWHERE...MUCH THE SAME AS KCLT ABOVE WITH AFTERNOON CONVECTION
LEADING TO POSSIBLE MVFR VISB RESTRICTIONS. INITIALIZED ALL TAFS
WITH NO WX MENTION ASIDE FOR KAVL WHERE VCTS PREVAILED DUE TO
PROXIMITY OF CURRENT RADAR ECHOES. NEVERTHELESS...ALL SITES HAVE
TEMPOS THIS AFTERNOON FOR ABOVE MENTIONED CONVECTION.
OTHERWISE...LOW VFR CIGS LIFT OVERNIGHT AS CONVECTION DIES DOWN AND
A COLD FRONT APPROACHES FROM THE WEST. THUS...KEPT ALL TAFS VFR
WITH THE EXCEPTION OF LIGHT MVFR BR AT KAVL/KHKY AMIDST LIGHT/CALM
SSW FLOW. WINDS WILL GRADUALLY START TO VEER WESTERLY NEAR PERIODS
END WITH KAVL BEING THE ONLY SITE WITH POST FROPA NW FLOW. WINDS
WILL LIKELY BE GUSTY ALONG AND BEHIND THE FRONTAL PASSAGE ON
TUESDAY...HOWEVER BEYOND THIS TAF CYCLE.
OUTLOOK...A COLD FRONT WILL CROSS THE AREA ON TUESDAY...POSSIBLY
BRINGING ANOTHER ROUND OF DIURNAL SHRA AND TSRA. DRIER AIR WILL MOVE
IN ON WEDNESDAY...BUT THE FRONT MAY STALL JUST TO THE
SOUTH...POSSIBLY ALLOWING UNSETTLED CONDITIONS TO RETURN TO THE AREA
LATE IN THE WEEK.
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 97% HIGH 97%
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...SBK
NEAR TERM...CDG/JDL
SHORT TERM...LG
LONG TERM...LG
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
320 PM CDT MON MAY 11 2015
.DISCUSSION...
PRE FRONTAL TROUGHING ATTEMPTING TO INITIATE CONVECTION ACROSS THE
MID STATE TODAY. CAP HAS BEEN WEAK ENOUGH OVER THE PLATEAU AND
WESTERN AREAS SO AS TO ALLOW CONVECTIVE ACTIVITY TO OCCUR. A FEW OF
THE STORMS HAVE BEEN STRONG ACROSS THE PLATEAU AREA. LATEST LAPS
DATA SHOWING AND INCREASE IN INSTABILITIES ACROSS OUR SOUTHWESTERN
ZONES. THE CURRENT LINE OF CONVECTION JUST NOW ENTERING STEWART
COUNTY WILL NEED TO BE WATCHED. HOWEVER...LATEST HRRR AND MODEL QPF
PROGS CONTINUE TO REFRAIN FROM SHOWING MUCH IN THE WAY OF AN
ORGANIZED EVENT.
FOR TONIGHT...THE FRONTAL BOUNDARY WILL PUSH INTO THE MID STATE
AFTER MIDNIGHT. NOT EXPECTING MUCH IN THE WAY OF CONVECTION ALONG
THE MAIN BOUNDARY...IT WILL MOSTLY BE PRE FRONTAL ACTIVITY.
OTW...DECREASING CLOUDS AFTER MIDNIGHT. POP LEVELS...AFT 00Z...WILL
GENERALLY RANGE FROM LESS THAN 20 PERCENT NW TO 40 PERCENT FOR THE
PLATEAU AREA.
TUES THROUGH WED NT WILL FEATURE DRY CONDITIONS WITH SEASONABLE
TEMPS. SFC PATTERN WILL KEEP A LIGHT NORTHERLY FETCH GOING WHILE
UPPER LEVEL RIDGING BUILDS IN. THIS WILL RESULT IN RATHER LARGE
DIURNAL TEMP SWINGS WITH LOWS GENERALLY IN THE LOW TO MID 50S FOR
TUES NT AND WED NT. HIGH TEMPS WILL BE WARMING INTO THE UPPER 70S TO
NEAR 80.
IN THE EXT FCST...PATTERN WILL BEGIN TO CHANGE. THE SFC HIGH...WHICH
BROUGHT THE FAIR WEATHER CONDITIONS TO THE AREA...WILL BE SLIDING
OFF TO THE EAST. A MOIST SOUTHERLY FLOW WILL RETURN AND WILL BE
AIDED BY A SOUTHWESTERLY FLOW IN THE MID AND UPPER LEVELS. IMPULSES
WILL RIDE NORTHEASTWARD AND PROVIDE A PROLONGED THREAT OF SHOWER AND
TSTM ACTIVITY THROUGH MUCH OF THE EXTENDED. BY THE END OF THE
EXTENDED...A FRONTAL BOUNDARY WILL ATTEMPT TO APPROACH. MEANWHILE
CAPE TO CAP RATIOS WILL BECOME MORE FAVORABLE. THUS...THE INTENSITY
OF TSTM ACTIVITY MAY BE ON THE INCREASE.
FOR THE EXT TEMPS...A SLOW WARMING AND HUMIDITY INCREASING TREND
WILL BE IN PLACE. BY THE END OF THE EXTENDED...TEMPS WILL REACH A
GOOD 10 TO 15 DEGREES ABOVE NORMAL.
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 59 77 50 79 / 20 05 0 05
CLARKSVILLE 54 76 48 77 / 10 05 0 05
CROSSVILLE 58 73 47 74 / 40 10 05 05
COLUMBIA 59 79 51 80 / 30 10 05 05
LAWRENCEBURG 58 79 51 79 / 30 10 05 0
WAVERLY 55 76 48 78 / 20 05 05 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1249 PM CDT MON MAY 11 2015
.UPDATE...FOR 18Z AVIATION.
&&
.AVIATION...
MAINLY VFR CONDITIONS FOR ALL THREE TERMINALS. SCATTERED
THUNDERSTORMS WILL BE AROUND THIS AFTERNOON. GIVE THE DECREASED
COVERAGE VIA THE HRRR ELECTED TO PUT IN VCTS INSTEAD OF A TEMPO
GROUP. WILL MONITOR THIS AFTERNOON FOR AMENDMENTS. WINDS WILL BE
GUSTY THIS AFTERNOON BEFORE RELAXING TONIGHT AND VEERING DUE TO
FROPA TONIGHT. LAMP DATA SUGGESTING SOME BR FOR CSV TONIGHT. WINDS
MAY STAY UP ENOUGH TO PREVENT THIS BUT INCLUDED TEMPO 5SM FOR
THIS.
REAGAN
&&
.PREV DISCUSSION... /ISSUED 1030 AM CDT MON MAY 11 2015/
UPDATE...
MAIN ITEM OF INTEREST FOR THE TODAY PERIOD IS THE CHANCES FOR A
COUPLE STRONG TO POSSIBLY SEVERE STORMS. SPC HAS OUR SW COUNTIES
HIGHLIGHTED WITH A SLIGHT RISK AND THE REST OF THE AREA WITH A
MARGINAL RISK. HRRR INDICATES 1000-1500 J/KG SBCAPE SNEAKING INTO
THE SOUTHWEST BY 18Z WITH SOME STORMS APPROACHING THAT AREA AT THE
TIME. CURRENTLY RADAR SHOWS SOME STORMS IN THE NORTH CENTRAL MS.
TIMING THESE STORMS OUT PUTS THEM INTO OUR WESTERN COUNTIES AROUND
19Z. LATEST RUN OF THE HRRR IS MORE BULLISH WITH THE AMOUNT OF
PRECIPITATION BROUGHT INTO THE AREA. PREVIOUS RUNS WERE MORE
SCATTERED IN NATURE. TEND TO AGREE WITH THE EARLIER RUNS GIVEN THE
LACK OF CONVERGENCE AND SUPPORT FOR THE STORMS. WITH ALL OF
THIS...KEPT POPS AS THEY WERE.
OVERALL HIGH TEMPERATURES ARE ON PACE. TWEAKED SOME HOURLY TEMPS
ESPECIALLY TO THE EAST WHERE FULL SUN HAS ALLOWED A QUICK WARM UP
BUT WARMING TRENDS SHOULD BE TEMPERED AS CLOUDS MOVE IN FROM THE
WEST.
REAGAN
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1228 PM CDT MON MAY 11 2015
.UPDATE...
UPDATE FOR THE 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 953 AM CDT MON MAY 11 2015/
UPDATE...
A BAND OF RAIN SHOWERS IS WEAKENING WHILE MOVING IN FROM THE WEST
WITH DEVELOPING SHOWERS AND THUNDERSTORMS SOUTH OF MEMPHIS ALONG
THE INTERSTATE 55 CORRIDOR. THE ATMOSPHERE IS PRETTY WELL WORKED
OVER ALONG AND WEST OF THE MISSISSIPPI RIVER...SO ANY ADDITIONAL
STRONG OR SEVERE STORMS WOULD DEVELOP IN EASTERN PORTIONS OF WEST
TENNESSEE AND IN NORTH MISSISSIPPI EAST ON INTERSTATE 55. CURRENT
THINKING IS THAT THE LINE IN NORTH MISSISSIPPI ALONG INTERSTATE 55
WILL CONTINUE TO STRENGTHEN AS IT SHIFTS EAST AND MAY BUILD
SLIGHTLY FARTHER NORTH INTO WEST TENNESSEE...BUT WILL MOST LIKELY
REMAIN BELOW SEVERE LIMITS AS EXTENSIVE CLOUD COVER OVER THE
REGION CURBS INSTABILITY. UPPER LEVEL SUPPORT FOR SEVERE STORMS
SHOULD CONTINUE TO DIMINISH WITH TIME.
PREV DISCUSSION... /ISSUED 618 AM CDT MON MAY 11 2015/
DISCUSSION...
UPDATED FOR 12Z AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 403 AM CDT MON MAY 11 2015/
DISCUSSION...
CURRENTLY...AN UPPER LOW IS CENTERED OVER THE NORTHERN PLAINS
MOVING NORTHEAST. MEANWHILE A MID LEVEL SHORTWAVE IS MOVING
ACROSS THE SOUTHERN PLAINS AND INTO THE LOWER MISSISSIPPI VALLEY.
THIS FEATURE HAS IGNITED AN AREA SHOWERS AND THUNDERSTORMS ACROSS
ARKANSAS INTO THE ARKLATEX REGION. A LEADING EDGE LINE OF SHOWERS
AND THUNDERSTORMS HAS MOVED INTO NORTHEAST ARKANSAS WHERE LOCALLY
HEAVY RAIN IS OCCURRING. RAIN RATES OF OVER 1 INCH PER HOUR HAVE
BEEN NOTED ACROSS RANDOLPH AND LAWRENCE COUNTIES. ELSW ACROSS THE
MIDSOUTH CLOUDS ARE INCREASING AND TEMPS ARE MILD...IN THE UPPER
60S AND LOWER 70S WITH A LIGHT SOUTH WIND.
TODAY...THIS LINE OF SHOWERS AND THUNDERSTORMS WILL PUSH ACROSS
THE MIDSOUTH THIS MORNING. GOOD UPPER LEVEL SUPPORT WILL HELP
MAINTAIN THE SHOWERS AND THUNDERSTORMS THROUGH ABOUT MID MORNING
AS THEY CROSS EASTERN ARKANSAS...THE MISSOURI BOOTHEEL AND THE
MISSISSIPPI RIVER. STRONG LOW LEVEL MOISTURE TRANSPORT INTO THE
DELTA REGION WILL HELP PRODUCE LOCALLY HEAVY RAINFALL...ESPECIALLY
WEST OF THE MISSISSIPPI RIVER WHERE 1 TO 2 INCHES COULD FALL WITH
LOCALLY HIGHER AMOUNTS. A FLASH FLOOD WATCH REMAIN IN EFFECT UNTIL
NOON WEST OF THE RIVER. MLCAPE VALUES ARE ABOUT 500 J/KG AHEAD OF
THE LINE OF THUNDERSTORMS ACROSS THE DELTA AND BULK SHEAR VALUES
ARE GREATER THAN 40 KTS. AS A RESULT A FEW STORMS COULD BE STRONG
TO SEVERE...MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH ABOUT MID
MORNING. DAMAGING WIND IS THE MAIN THREAT.
AS THE LINE HEADS EAST OF THE MISSISSIPPI RIVER IT WILL WEAKEN AS
THE BETTER UPPER SUPPORT LIFTS NORTHEAST. THE LATEST HRRR DEPICTS
THE REMNANTS OF THE LINE REACHING THE TN RIVER BY ABOUT 18Z.
THERE IS THE QUESTION OF REDEVELOPMENT ALONG THE COLD FRONT AS IT
MOVES INTO THE AREA LATER TODAY AND THIS EVENING. ATTM IT LOOKS
LIKE REDEVELOPMENT WILL BE RATHER MEAGER. FIRST THE COLD FRONT IS
WEAKENING AS IT MOVES INTO THE REGION AND CONVERGENCE ALONG THE
FRONT IS WEAK. ALSO EXPECT A GOOD DEAL OF STRATIFORM RAIN BEHIND
THE INITIAL LINE OF THUNDERSTORMS THAT WILL LAST MUCH OF THE
MORNING. THIS WILL SERVE TO STABILIZE THE AIRMASS AND REALLY DO
NOT SEE IT RECOVERING ENOUGH TO PROMOTE DEVELOPMENT LATER THIS
AFTERNOON INTO THE EVENING. LASTLY MID LEVEL HEIGHTS START TO
RISE. THIS SCENARIO JUST DOES NOT LOOK FAVORABLE FOR
REDEVELOPMENT AND THE LATEST HRRR CORROBORATES THAT.
THE AREA WILL START TO DRY OUT FROM THE NORTHWEST THIS AFTERNOON.
TONIGHT...LEFT SOME LINGERING SHOWERS AND THUNDERSTORMS SOUTH OF
I-40 FOR THE EVENING AS THE WEAK COLD FRONT PUSHES THROUGH. OTRW
SKIES WILL BE CLEARING OVERNIGHT AS SURFACE HIGH PRESSURE STARTS
TO BUILD IN. LOWS WILL DROP INTO THE 50S NORTH TO LOWER 60S
SOUTH.
TUESDAY AND WEDNESDAY...THESE LOOK LIKE SOME VERY NICE DAYS WITH
LOW HUMIDITY AND PLEASANT TEMPS AS HIGH PRESSURE PREVAILS. HIGHS
WILL BE IN THE 70S. LOWS WEDNESDAY MORNING COULD DIP INTO THE
UPPER 40S IN THE COOLER SPOTS.
THURSDAY THROUGH SUNDAY...FRONT WILL LIFT BACK NORTH AS WARM
FRONT AND THE HUMIDITY LEVELS WILL INCREASE LATER IN THE WEEK. THE
UPPER FLOW WILL TRANSITION BACK TO SOUTHWEST FLOW WITH CHANCES
FOR SHOWERS AND THUNDERSTORMS AS DISTURBANCES MOVE THROUGH ALOFT.
HIGH TEMPS WILL BE IN THE LOWER TO MID 80S BY THE END OF THE WEEK
WITH LOWS IN THE 60S.
SJM
&&
.AVIATION...
18Z TAF CYCLE
CURRENT MVFR CEILINGS AT KJBR SHOULD IMPROVE LATER THIS AFTERNOON
OTHERWISE VFR CONDITIONS WILL PERSIST FOR MUCH OF THE FORECAST
PERIOD. SOME SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS MAINLY
EASTERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON. WINDS WILL
BE MAINLY FROM THE WEST AROUND 10 KNOTS FOR MOST OF THE FORECAST
PERIOD.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1231 PM CDT MON MAY 11 2015
.DISCUSSION...SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...WILL HAVE CONVECTION IN THE 24 HOUR TERMINALS...AND DO
THE BEST POSSIBLE BASED ON THE 4KM MODELS WHICH ARE PRETTY MUCH
SHOWING RAIN IN FOR THE AREA OVER THE NEXT SEVERAL HOURS. AM
BETTING THAT THERE WILL BE SOME ORGANIZED CONVECTION DEVELOPING BY
EARLY EVENING OVER THE WESTERN PORTIONS OF THE CWFA...THEN SPREAD
EAST. THIS MAIN CONVECTIVE LINE FORECAST WILL PROVIDE THE
STRONGEST STORMS THIS EVENING UNTIL ABOUT 12/07Z OR SO...BUT THEN
WILL HAVE AT LEAST VCTS AND/OR VCSH IN THE REMAINDER OF THE
FORECAST (WITH -TSRA AOB 12Z). CONVECTION FIRING UP AS THIS IS
BEING WRITTEN...SO WILL HAVE VCSH/VCTS AND TEMPOS THROUGH 11/24Z
FOR ALL TERMINALS...WITH GENERALLY VFR CONDITIONS OUTSIDE OF
CONVECTION. THEN MAIN CONVECTION WILL BEGIN AT KLRD SOMETIME
BETWEEN 22Z AND 02Z...THEN THROUGH THE EASTERN TERMINALS SOMETIME
BETWEEN 02Z AND 07Z (HERE WILL HAVE TEMPOS WITH STRONG WIND
GUSTS). AFTER THAT...WILL CONTINUE WITH -TSRA CATEGORICAL (COULD
HAVE STRONGER STORMS TOO AFTER 07Z BUT HAVE TO KEEP IT
SHORT)...THEN VCSH AT KALI AND KCRP IN THE MORNING WITH SHRA AT
KVCT AND TSRA AT KLRD...THE LATTER EXPECTED DUE TO WEAK OROGRAPHIC
FLOW FROM EASTERLY WINDS. FOR THE MOST PART...WINDS WILL BE
EASTERLY AFTER 12/00Z AND LESS THAN 11 KNOTS OUT OF THUNDER. WITH
THIS PATTERN...CANNOT NAIL TIMING OF CONVECTION AND/OR STRONGEST
STORMS SO THERE LIKELY WILL BE UPDATES TO THE TERMINALS FROM TIME
TO TIME.
&&
.PREV DISCUSSION... /ISSUED 947 AM CDT MON MAY 11 2015/
DISCUSSION...GFE FORECAST MONITOR SHOWING THINGS ARE FINE WITH
RESPECT TO TEMPS/WINDS AND CLOUDS. CONCERNING RAIN CHANCES...SOME
SPOTTY SHOWERS STARTING TO SHOW UP MAINLY OVER THE NORTHERN AREAS
WHERE SURFACE CONVERGENCE IS LOCATED AND CAP IS ERODING FAST.
OVERALL...FORECAST LOOKS GOOD. BASED ON 4 KM MODELS AND
APPROACHING CONVECTION SEEPING SLOWLY SOUTHWARD...WILL MENTION
SEVERE FOR THIS AFTERNOON OVER THE WESTERN AREAS (AND MAY INCLUDE
REMAINDER OF NORTHERN AREAS IF DIFFERENT TRENDS DEVELOP)...BUT
THINK MAIN CONCERN WILL BE WESTERN AREAS. ALSO WILL MENTION HEAVY
RAINFALL OVER THE NORTHERN AREAS THIS AFTERNOON AND ALL AREAS
TONIGHT. CONCERNING RIP CURRENT RISK...IT IS STARTING TO GO DOWN
BUT IT WAS CLOSE THIS MORNING. BASED ON OBSERVATIONS FROM
BOY020...SWELLS HAVE FALLEN TO 4 FEET OR LESS (AND TREND IS
FALLING)...WITH PERIODS STILL 7 TO 8 FEET. MODERATE WILL DO.
TIDES ARE STILL WELL BELOW 2 FEET...WITH MOST BELOW 1.5 FEET AND
HEIGHTS OF HIGH TIDES ARE SLIGHTLY LOWER. MARINE FORECAST IS OK.
MINOR UPDATES OF PRODUCTS WILL BE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 636 AM CDT MON MAY 11 2015/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...LOW END VFR AND MVFR CEILINGS CAN BE EXPECTED THROUGH
MUCH OF THE PERIOD. CHANCES FOR SHOWERS AND STORMS WILL INCREASE
AS SLOW MOVING COLD FRONT APPROACHES SOUTH TEXAS. LATEST HRRR HAS
SLOWED DOWN ONSET OF CONVECTION SO WILL KEEP VCTS REMARKS FOR
NOW. IF THUNDERSTORMS DIRECTLY IMPACT THE TERMINALS...HEAVY
RAIN...BRIEF GUSTY WINDS AND REDUCED VSBYS WILL BE LIKELY. WINDS
THROUGH THE PERIOD WILL BE PREDOMINANTLY OUT OF THE E AND ESE WITH
SPEEDS LESS THAN 15 KNOTS.
PREV DISCUSSION... /ISSUED 427 AM CDT MON MAY 11 2015/
SHORT TERM (TODAY THROUGH TUESDAY)...MAIN FOCUS THROUGH THE SHORT
TERM WILL BE THUNDERSTORM CHANCES. UPPER LEVEL TROUGH OVER THE
CENTRAL/SOUTHERN PLAINS WILL LIFT TO THE NORTHEAST INTO THE OHIO
VALLEY AND GREAT LAKES REGION. AT THE SURFACE...SLOW MOVING COLD
FRONT WILL CONTINUE TO APPROACH THE AREA. LOW LEVEL E/SE FLOW WILL
ALLOW DEEP MOISTURE TO REMAIN ACROSS SOUTH TEXAS. MODELS PROG PW
VALUES TO BE BETWEEN 1.8 AND 2.0 INCHES...WHICH IS WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. THESE FACTORS WILL LEAD TO
INCREASING THUNDERSTORM CHANCES THROUGH THE SHORT TERM.
CURRENTLY...A SQUALL LINE IS PUSHING ACROSS EASTERN TEXAS.
ADDITIONAL CONVECTION HAS RECENTLY DEVELOPED OVER THE EDWARDS
PLATEAU INTO THE HILL COUNTRY. LATEST HRRR RUNS HAVE BEEN HINTING
AT THIS AND EVENTUALLY BRING SOME OF THIS ACTIVITY TO THE SE
THROUGH THE MORNING...APPROACHING THE N AND NW SECTIONS BY MIDDAY.
ADDITIONAL CONVECTION WILL THEN BE POSSIBLE LATE THIS AFTERNOON
AND EVENING FROM THE WEST AS UPPER DISTURBANCE IN W/WSW FLOW ALOFT
TRAVERSES THE AREA. WILL HAVE TO CONTINUE TO MONITOR THE
POSSIBILITY OF SOME STRONG TO SEVERE STORMS TODAY. PRIMARY HAZARDS
WOULD BE LARGE HAIL AND DAMAGING WINDS WITH SUFFICIENT
INSTABILITY/SHEAR OVER THE REGION. ALSO INCLUDED A MENTION OF
HEAVY RAIN TONIGHT AS BOUNDARY DRAWS NEAR. WILL NOT ISSUE A FLASH
FLOOD WATCH AT THIS TIME BUT ONE MAY BECOME NECESSARY IN LATER
SHIFTS. UNSETTLED WEATHER WILL PERSIST INTO TUESDAY AS COLD FRONT
AND DEEP MOISTURE REMAINS IN THE VICINITY. POPS ON TUESDAY RANGE
FROM 80 PERCENT ACROSS THE NORTH TO 50 ACROSS THE SOUTH. SLIGHT
RISK OF SEVERE WEATHER WILL EXIST ON TUESDAY AS MODELS STILL
FORECAST UNSTABLE AIRMASS ACROSS SOUTH TEXAS. THE THREAT OF
MODERATE TO HEAVY RAIN WILL CONTINUE INTO TUESDAY AS WELL.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...ACTIVE WET PERIOD
CONTINUES TO BE IN STORE FOR MUCH OF THE WEEK. FRONTAL BOUNDARY WILL
BE TO THE NORTH OF THE AREA BEGINNING THE PERIOD...WITH DEEP
ABUNDANT MOISTURE ACROSS THE REGION. SEVERAL ROUNDS OF SHORTWAVES
WILL MOVE ACROSS THE REGION...PROVIDING UPPER SUPPORT FOR CONVECTION
ACROSS THE REGION THROUGH THE MID WEEK. FRONTAL BOUNDARY DISSIPATES
LATE IN THE WEEK WITH ANOTHER UPPER TROUGH DIGGING INTO THE DESERT
SOUTHWEST. POPS WILL DECREASE ACROSS THE REGION FRIDAY INTO THE
WEEKEND...THOUGH WILL STILL MAINTAIN SLIGHT CHANCE TO LOW END CHANCE
POPS BY THE WEEKEND. STILL ANTICIPATING HIGH QPF POTENTIAL FOR THIS
WEEK...WITH AREAS POSSIBLY RECEIVING RAINFALL AMOUNTS IN EXCESS OF 5
INCHES ACROSS THE NORTHERN BRUSH COUNTRY...TO OVER 2 INCHES POSSIBLE
ALONG THE COASTAL BEND THROUGH THE WEEK.
A GRADUAL WARMING TREND CAN BE EXPECTED FROM MID WEEK ONWARD...WITH
HIGHS IN THE LOW TO MID 80S WEDNESDAY...AND IN THE MID 80S TO LOWER
90S BY THE WEEKEND. LOWS WILL ALSO BE ON THE RISE...GOING FROM THE
LOWER 70S EARLY IN THE WEEK TO THE MID 70S BY THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 85 75 82 74 81 / 40 80 60 70 40
VICTORIA 86 72 81 71 81 / 60 80 80 70 50
LAREDO 88 72 84 72 84 / 50 80 70 70 60
ALICE 87 73 83 72 83 / 50 80 60 70 40
ROCKPORT 84 75 80 74 80 / 40 80 60 70 40
COTULLA 86 70 81 69 83 / 60 90 80 70 70
KINGSVILLE 87 74 83 73 83 / 40 80 60 60 40
NAVY CORPUS 83 75 81 75 80 / 40 80 60 60 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...AVIATION