Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/09/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
830 PM MST FRI MAY 8 2015
.SYNOPSIS...A WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA
THROUGH SATURDAY BRINGING GUSTY WINDS...MUCH COOLER TEMPERATURES AND
A FEW SHOWERS OR THUNDERSTORMS MAINLY NORTH OF TUCSON. UNSEASONABLY
COOL OVERNIGHT LOWS SATURDAY MORNING AND SUNDAY MORNING.
THEREAFTER...DRY AND WARMER WEATHER WILL RETURN NEXT WEEK.
&&
.DISCUSSION...COOLER AIR FILTERING IN UNDER THE LOW AS IT PUSHES
THROUGH THE STATE NORTH OF OUR AREA OVER THE NEXT 24 HOURS. ALSO
SEEING DRY AIR WRAPPING INTO SOUTHERN ARIZONA FROM THE SOUTH THIS
EVENING AS PRECIPITABLE WATER FALLS TO AROUND 1/3 OF AN INCH BEFORE
BRIEFLY PUSHING BACK UP TOWARD 1/2 INCH FOR A FEW HOURS TOMORROW. AS
WINDS DIMINISH OVERNIGHT IN MOST LOCATIONS...WE WILL SEE OVERNIGHT
LOWS ABOUT 6 TO 10 DEGREES BELOW AVERAGE. COULD BE A DEGREE OR TWO
COOLER IN EASTERN AREAS TOMORROW NIGHT BUT WE CURRENTLY DON`T EXPECT
FREEZING TEMPERATURES OUTSIDE OF MOUNTAIN LOCATIONS. WINDS NOT AS
STRONG SATURDAY BUT STILL BREEZY IN SPOTS.
&&
.AVIATION...VALID THRU 10/06Z. MAINLY SCT TO OCCASIONALLY BKN CLOUD
COVERAGE AT 4-7K FT AGL WILL CONTINUE INTO SATURDAY AS AN AREA OF
LOW PRESSURE MOVES ACROSS ARIZONA. ISOLD -SHRA/-TSRA PSBL MAINLY
NORTH OF KTUS THROUGH THE PERIOD. GUSTY WINDS WILL CONTINUE INTO
THIS EVENING WITH THE STRONGEST WINDS AT KDUG AND KOLS WITH SPEEDS
EXPECTED TO RANGE FROM 20 TO 25 KNOTS...WITH GUSTS OF 30 TO 35 KTS.
WINDS WILL BECOME GENERALLY LESS THAN 10 KNOTS AFTER 09/06Z BEFORE
WESTERLY WINDS INCREASE TO 10 TO 15 KTS SATURDAY AFTER 18Z. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...GUSTY WINDS WILL CONTINUE EARLY THIS
EVENING...ESPECIALLY SOUTH AND EAST OF TUCSON. THE LOW PRESSURE
RESULTING IN THESE WINDS WILL ALSO RESULT IN A FEW SHOWERS MAINLY
NORTH OF TUCSON TONIGHT.
LIGHTER WINDS ARE EXPECTED SATURDAY WITH A THREAT OF A FEW SHOWERS
AND THUNDERSTORMS MAINLY NORTH OF TUCSON AS THE LOW PRESSURE SYSTEM
MOVES NORTH OF THE AREA. FOR SUNDAY THROUGH THURSDAY WARMER AND DRY
WEATHER IS EXPECTED WITH TYPICAL DIURNAL WINDS ACROSS THE REGION.
&&
.PREV DISCUSSION...ISOLATED TO SCATTERED SHOWERS WERE DEVELOPING
ACROSS NORTHERN AND CENTRAL ARIZONA THIS AFTERNOON AS A LOW PRESSURE
SYSTEM OVER SOUTHERN NEVADA APPROACHES. MODELS KEEP THE BEST CHANCE
OF SHOWERS OR THUNDERSTORMS ACROSS NORTHERN ARIZONA INTO THE WHITE
MOUNTAINS. LATEST HRRR SOLUTION SHOWED A FEW SHOWERS FARTHER SOUTH
INTO PINAL AND PIMA COUNTIES. BASED ON RECENT TRENDS IN THE
SATELLITE AND RADAR IMAGERY...WILL INTRODUCE POP VALUES FARTHER
SOUTH THAN PREVIOUSLY FORECAST. OTHERWISE...WIND SPEEDS WILL TAPER
OFF LATER THIS EVENING MOST AREAS AS THE SYSTEM PASSES THROUGH
NORTHERN ARIZONA. WILL KEEP SOME LINGER SHOWERS IN THE WHITE
MOUNTAINS ON SATURDAY INTO SUNDAY...BUT DRY AND COOL FOR THIS TIME
OF YEAR ELSEWHERE. MODELS WARM DAYTIME TEMPERATURES BACK UP TO NEAR
SEASONAL READINGS EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE ALOFT
BUILDS OVER THE AREA. THIS RIDGE WILL SHIFT EASTWARD BY THE MIDDLE
OF NEXT WEEK AS A SYSTEM APPROACHES THE WEST COAST.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
913 AM PDT Thu May 7 2015
.Synopsis...
A storm over NorCal will bring scattered showers or thunderstorms
through tonight with Sierra showers into Friday. Periods of breezy
north winds. Chance of showers or thunderstorms again early next
week mainly northern mountains.
&&
.Discussion (Today through Saturday)...
Have made a few updates this morning. Increased snow amounts in
the Sierra so that the Winter Weather Advisory now reflects snow
totals of 3-8 inches above 5000 ft around Hwy 50 southward. We
also increased the area of showers/thunderstorms for today as
this storm lingers over the region. Much of the shower activity
will be along the Interstate 80 corridor and southward today into
tonight. The high resolution HRRR model suggests that another wave
a precipitation could wrap around the Sierra towards the
Sacramento Metro region later tonight around 10 pm. Will look at
other models to see if we need to increase precipitation chances
for tonight. JBB
.Previous Discussion...Upper level closed low has dropped southward into
Northern California this morning. Disturbances pivoting around the
base of the low are generating showers over Norcal south of line
from about Chester to Clear Lake and north of about Sacramento.
The low is forecast to continue southward into Socal later today
and this evening. Stability progs show slightly unstable
conditions across much of the CWA so can not rule out a threat of
thunderstorms just about anywhere in the forecast area especially
this afternoon when daytime surface heating maxes out for the day.
Cool upper low will bring down daytime highs today to near normal
for this time of year. Surface high pressure pushing in behind the
upper low over the Pacific Northwest has created a fairly tight
surface gradient across the north state and this is producing
gusty north winds some areas. Current MFR to SAC gradient is 12mb.
Upper level support is only weak however so the strongest winds
are likely to be spotty and fairly short lived. Decreasing
gradients and winds are expected by this afternoon. Upper low is
progged to be over Socal by late this afternoon. Therefore focus
of heaviest precip expected to be over the Sierra south of about
Tahoe. Still looks to be enough snowfall at pass levels to justify
winter weather advisory currently in place from highway 50
southward. Upper low continues southeastward on Friday with rap
around moisture keeping a threat of showers over the Sierra but
allowing for warming temperatures most other locations. Upper low
moves eastward into the eastern Great Basin on Saturday bringing
clearing skies and still warmer temperatures but a disturbance
pivoting down the backside of the low could bring a stray shower
over the northern Sierra Saturday afternoon. Models show an upper
ridge over the west coast late Saturday and early Sunday so most
of the weekend should be under fair skies with daytime highs
pushing up to between 5 to 10 degrees above normal. A weak Pacific
low is forecast by mid range models to approach the coast late
Sunday bringing a threat of showers to the northwest corner of the
state by late Sunday afternoon or evening.
.Extended Discussion (Monday through Thursday)
Another upper low is forecast to dig south along the NW Cal coast
Monday. Models then differ significantly on how quickly to eject
the low by Wednesday. Potential for showers and thunderstorms
exist early next week, with Monday/Tuesday expected to be the most
active day. The GFS and GEM have more active weather with the low
over CA, while the EC tends to be drier and keeps the low offshore
of Oregon with only weak troughing over area. Cooling trend
expected with afternoon highs near to just below normal next week.
JClapp
&&
.Aviation...
Localized MVFR (bases 010 to 020) across area with showers and
t-storms today. Northerly sfc wind gusts to 30 kts today into
this evening. N-NE flight level 020 to 030 winds of 30-40 kts
late this aftn through evening as low moves south of area.
JClapp
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 5 am pdt friday west slope
northern sierra nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
347 AM PDT Thu May 7 2015
.Synopsis...
A low pressure system dropping through northern California will
bring scattered showers or thunderstorms to much of Norcal today
then to the Sierra through the end of the week. Near normal
temperatures today then warming into the weekend. Breezy north
winds today mainly on the West side of the Valley. Chance of
showers or thunderstorms again early next week mainly northern
mountains.
&&
.Discussion (Today through Saturday)...
Upper level closed low has dropped southward into Northern
California this morning. Disturbances pivoting around the base of
the low are generating showers over Norcal south of line from about
Chester to Clear Lake and north of about Sacramento. The low is
forecast to continue southward into Socal later today and this
evening. Stability progs show slightly unstable conditions across
much of the CWA so can not rule out a threat of thunderstorms just
about anywhere in the forecast area especially this afternoon when
daytime surface heating maxes out for the day. Cool upper low will
bring down daytime highs today to near normal for this time of
year. Surface high pressure pushing in behind the upper low over
the Pacific Northwest has created a fairly tight surface gradient
across the north state and this is producing gusty north winds some
areas. Current MFR to SAC gradient is 12mb. Upper level support is
only weak however so the strongest winds are likely to be spotty
and fairly short lived. Decreasing gradients and winds are
expected by this afternoon. Upper low is progged to be over Socal
by late this afternoon. Therefore focus of heaviest precip
expected to be over the Sierra south of about Tahoe. Still looks
to be enough snowfall at pass levels to justify winter weather
advisory currently in place from highway 50 southward. Upper low
continues southeastward on Friday with RAP around moisture keeping
a threat of showers over the Sierra but allowing for warming
temperatures most other locations. Upper low moves eastward into
the eastern Great Basin on Saturday bringing clearing skies and
still warmer temperatures but a disturbance pivoting down the
backside of the low could bring a stray shower over the northern
Sierra Saturday afternoon. Models show an upper ridge over the west
coast late Saturday and early Sunday so most of the weekend should
be under fair skies with daytime highs pushing up to between 5 to
10 degrees above normal. A weak Pacific low is forecast by mid
range models to approach the coast late Sunday bringing a threat
of showers to the northwest corner of the state by late Sunday
afternoon or evening.
.Extended Discussion (Monday through Thursday)
Another upper low is forecast to dig south along the NW Cal coast
Monday. Models then differ significantly on how quickly to eject
the low by Wednesday. Potential for showers and thunderstorms
exist early next week, with Monday/Tuesday expected to be the most
active day. The GFS and GEM have more active weather with the low
over CA, while the EC tends to be drier and keeps the low offshore
of Oregon with only weak troughing over area. Cooling trend
expected with afternoon highs near to just below normal next week.
JClapp
&&
.Aviation...
Localized MVFR (bases 010 to 020) across area with showers and
t-storms today. Northerly sfc wind gusts to 30 kts today into
this evening. N-NE flight level 020 to 030 winds of 30-40 kts
late this aftn through evening as low moves south of area.
JClapp
&&
.STO Watches/Warnings/Advisories...
winter weather advisory until 5 am pdt friday west slope
northern sierra nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
949 PM MDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 927 PM MDT FRI MAY 8 2015
BANDS OF MODERATE TO HEAVY RAIN CONTINUE TO MOVE NORTHWARD ALONG
THE INTERSTATE 25 CORRIDOR THIS EVENING. STRONG CONVERGENCE ZONE
SEEMS TO BE ANCHORING THESE STORMS WITH MODERATE TO HEAVY RAIN
OCCURRING. EXPECT THIS TO CONTINUE FOR MUCH OF TONIGHT AHEAD OF
THE APPROACHING STRONG LOW OVER SOUTHERN NEVADA. ADDITIONAL
SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL ALSO DRIFT FURTHER
EAST OVER NORTHEAST COLORADO BUT WITH LESS COVERAGE THAN FURTHER
WEST. WILL ADJUST ZONES FOR CURRENT EVENING TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 225 PM MDT FRI MAY 8 2015
STRONG UPPER LEVEL LOW IS CURRENTLY OVER LAS VEGAS MOVING SLOWLY
EASTWARD. AHEAD OF THIS SYSTEM THERE HAVE BEEN A COUPLE OF
DISTINCT WAVES THAT ORGANIZED THE PRECIPITATION TODAY. ONE MOVED
BY EARLIER AND THE SECOND IS MOVING NORTHWARD ACROSS THE FORECAST
AREA RIGHT NOW. THERE IS SOME CLEARING BEHIND THE SECOND WAVE BUT
ALL MODELS HAVE ANOTHER WAVE OF UPPER LEVEL FORCING WILL BE
MOVING NORTH FROM SOUTHEAST COLORADO OVERNIGHT. THIS FEATURE WAS
SEEN NICELY IN THE CIRA SYNTHETIC IMAGERY FROM THE NAM NEST
OVERLAID WITH SOME FORCING FIELDS ON AWIPS. WITH THIS EXPECT
INCREASE IN SHOWER ACTIVITY ACROSS THE PLAINS OVERNIGHT AS SEEN IN
THE HRRR RUNS OF LATE AND INCREASED POPS FROM SOUTH TO NORTH TO
LIKELY BEFORE DECREASING THEM AGAIN LATER TONIGHT FROM SOUTH TO
NORTH. RAINFALL AMOUNTS COULD BE AS HIGH AS AN INCH OR SO IN SOME
AREAS BUT NO REAL FOCUS INDICATED AT THIS TIME TO WARRANT ANY
HYDROLOGY HIGHLIGHTS BEYOND WHAT HAS BEEN PUT OUT AT THIS TIME.
A VERY ACTIVE DAY IN STORE FOR SATURDAY WITH ALL KINDS OF WEATHER
ACROSS THE AREA. MODELS ARE IN GENERAL AGREEMENT IN MOVING THE
UPPER LEVEL LOW NORTHEASTWARD ACROSS THE 4 CORNERS REGION AND INTO
EASTERN COLORADO BY THE END OF THE DAY. THIS WILL BRING OF COURSE
A LARGE AMOUNT OF UPPER LEVEL FORCING WITH IT...FIRST ACROSS THE
MOUNTAINS AND THEN INTO EASTERN COLORADO BY THE AFTERNOON. THE 700
MB LOW INITIALLY STARTS OUT RATHER ELONGATED BUT THEN WITH RAPID
CYCLOGENESIS EAST OF THE MOUNTAINS IT CONSOLIDATES NEAR LIMON
AFTER 00Z/SUNDAY. OROGRAPHIC FLOW WILL NOT BE FAVORABLE IN THE
MOUNTAINS WEST OF THE DIVIDE UNTIL THE UPPER LOW PASSES BY SAT
NIGHT BUT WITH THE STRONG DYNAMICS SHOULD SEE SNOW INCREASE WITH
EMBEDDED THUNDERSTORMS AS THE DAY GOES ON. FOR NOW KEPT THE WATCH
AS IS BUT WOULD LIKELY BE ENOUGH TO HOIST A WARNING ALTHOUGH
LOWERED OVERALL AMOUNTS TO 8 TO 16 INCHES TOTAL. SOME ADDITIONAL
SNOW TONIGHT BUT MORE SCATTERED IN COVERAGE WITH SNOW LEVEL DOWN
TO AROUND 9000 FEET. ON THE PLAINS SHOULD BE A LULL IN THE
PRECIPITATION IN THE MORNING WITH SOME PARTIAL CLEARING THAT COULD
SET THE STAGE FOR SEVERE WEATHER AS THE SYSTEM REDEVELOPS EAST OF
THE MOUNTAINS. BEST CHANCES FOR SEVERE WOULD LIKELY BE MORE TO THE
EASTERN PART OF THE PLAINS BUT COULD GET ALL THE WAY BACK TO THE
URBAN CORRIDOR. THEN UPSLOPE SHOULD INCREASE LATE WITH MORE
WIDESPREAD PRECIPITATION DEVELOPING FROM NORTH TO SOUTH LATER IN
THE AFTERNOON. SNOW CHANCES AT LOWER ELEVATIONS COME LATER IN THE
PERIOD AS COLDER AIR COMES IN ON THE BACKSIDE OF THE SYSTEM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 225 PM MDT FRI MAY 8 2015
STRONG UPPER LOW WILL MOVE FROM SOUTH CENTRAL COLORADO 00Z SUNDAY TO
SOUTHWEST NEBRASKA 12Z SUNDAY. THE SURFACE LOW WILL TRACK TO THE
NORTHEAST OF THE UPPER LEVEL LOW. STRONG TO SEVERE STORMS MAY LINGER
INTO THE EARLY EVENING HOURS OVER THE PLAINS. AFTER THIS...A
DEFORMATION ZONE WILL DEVELOP ON THE BACKSIDE OF THE LOW.
PRECIPITATION WILL START OFF AS RAIN...BUT QUICKLY TURN TO SNOW
SATURDAY EVENING ACROSS THE PLAINS. UNCERTAIN WHERE THIS ZONE WILL
FORM...BASED ON SLIGHTLY DIFFERENT STORM TRACKS. EXPECT MOST AREAS
TO SEE PERIOD OF SNOW...WITH A SMALL BAND OF 3 TO 6 INCHES OF
SNOWFALL EAST OF I-25 BY SUNDAY MORNING.
RAIN AND SNOW WILL END SUNDAY MORNING AS THE LOW LIFTS NORTHEAST OF
THE REGION. IT WILL BE CLOUDY A COOL BEHIND THE SYSTEM WITH HIGHS
MAINLY IN THE 40S. IT WILL BE SLIGHTLY UNSTABLE IN THE MOUNTAINS
WITH ISOLATED/SCATTERED SNOW SHOWERS. FOR SUNDAY NIGHT...FROST WILL
BE LIKELY MOST LOCATIONS AS SKIES PARTIALLY CLEAR. EXPECT LOW ACROSS
THE AREA TO BE IN THE 20S TO LOWER 30S.
FOR EARLY NEXT WEEK...UPPER LEVEL RIDGE WILL MOVE ACROSS THE REGION
MONDAY AND MONDAY NIGHT. THIS WILL BRINGING DRIER CONDITIONS TO THE
AREA. STILL A SLIGHT CHANCE FOR SHOWERS OVER THE MOUNTAINS...
OTHERWISE DRY CONDITIONS WILL PREVAIL. IT WILL BE COOL MONDAY BEHIND
THE EXITING LOW WITH HIGHS IN THE 50S TO LOWER 60S ACROSS NORTHEAST
COLORADO.
ON TUESDAY...FLOW ALOFT WILL BECOME SOUTHWESTERLY AS AN UPPER LEVEL
LOW DIGS SOUTH ALONG THE CALIFORNIA COAST. TEMPERATURES WILL WARM
INTO THE 60S TUESDAY UNDER THE SOUTHWESTERLY. MAY BE ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS ACROSS THE AREA.
THE LOW WILL WEAKEN AND LIFT NORTHEAST ACROSS THE INTERMOUNTAIN WEST
ON WEDNESDAY. AS THE TROUGH AXIS MOVES ACROSS THE REGION...EXPECT IT
TO PRODUCE SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS. WILL
BUMP POPS UP INTO THE SCATTERED RANGE FOR THIS. TEMPERATURES WILL
ALSO WARM AS A SOUTH TO SOUTHWEST FLOW PREVAILS.
FOR THURSDAY AND FRIDAY...ANOTHER UPPER LEVEL LOW MOVES OVER
CALIFORNIA. THIS WILL KEEP A SOUTHWEST FLOW ALOFT ACROSS THE CENTRAL
ROCKIES. THERE IS A SHORT WAVE RIDGE FOLLOWING WEDNESDAY`S SYSTEM.
WILL BE TRICKY TO TIME THIS...BUT THERE SHOULD BE A WINDOW WHERE IT
WILL BE DRY ACROSS THE AREA. ONCE THIS RIDGE SHIFTS EAST OF THE
AREA. EXPECTED SCATTERED/ISOLATED SHOWERS AND THUNDERSTORMS TO
RETURN TO THE REGION. WILL GO WITH ISOLATED TO SCATTERED POPS FOR
THURSDAY AND FRIDAY...WITH THE LOWER POPS ON THURSDAY WHEN THIS
RIDGE MAY MOVE ACROSS THE AREA. TEMPERATURES WILL REMAIN COOL WITH
HIGHS IN THE 60S...SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 927 PM MDT FRI MAY 8 2015
RAIN SHOWERS EXPECTED FOR MUCH OF THE NIGHT WITH MVFR CONDITIONS
AS CONTINUED MOISTURE STREAMS IN FROM THE SOUTH. MODERATE
SOUTHEAST WINDS AT KDEN BUT MORE WEST AND NORTHWEST OVER APA/BJC
WITH CONVERGENCE BOUDARY STRETCHING NORTH TO SOUTH ALONG
INTERSTATE 25.
&&
.HYDROLOGY...
ISSUED AT 927 PM MDT FRI MAY 8 2015
HAVE JUST ISSUED AN AREAL FLOODING WARNING THROUGH MID MORNING
SATURDAY FOR PORTIONS OF LARIMER....WESTERN WELD...BOULDER AND
BROOMFIELD COUNTIES WITH PERSISTENT RAINFALL FOR 1-1.5 INCHES
THAT HAVE ALREADY FALLEN IN THE PAST 12 HOURS. ALREADY GETTING
REPORTS OF FIELD FLOODING AND FLOODING PROBLEMS OVER BOULDER AND
ST VRAIN CREEKS. PERSISTENT RAINFALL TONIGHT WILL LIKELY RESULT
IN CREEKS TO CONTINUE TO RISE THROUGH SATURDAY AM. COULD SEE YET
ANOTHER INCH OF RAIN THROUGH THE NIGHT.
SOUTH PLATTE RIVER ALSO EXPECTED TO REACH FLOOD STATE NEAR KERSEY
BY SATURDAY EVENING AND WILL ISSUE A FLOOD WARNING FOR PORTIONS OF
THE SOUTH PLATTE IN THAT AREA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
.AREAL FLOODING WARNING UNTIL 915 AM SATURDAY MORNING FOR
SOUTHEAST LARIMER...BOULDER..SOUTHWEST WELD...AND CENTRAL
BROOMFIELD COUNTIES.
.FLOOD WARNING ALONG THE SOUTH PLATTE RIVER FROM KERSEY TO BALZAC
FROM SATURDAY EVENING THROUGH TUESDAY NIGHT.
.WINTER STORM WATCH FROM SATURDAY AFTERNOON THROUGH LATE SATURDAY
NIGHT FOR COZ033-034.
&&
$$
UPDATE...ENTREKIN
SHORT TERM...SZOKE
LONG TERM...MEIER
AVIATION...ENTREKIN
HYDROLOGY...ENTREKIN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
908 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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 210 PM MDT FRI MAY 8 2015
AT KCOS...MVFR CONDITIONS THROUGH THE NIGHT WITH OCCASIONAL
-SHRA/-TSRA AND PERIODS OF IFR UNDER HEAVIER PRECIP LOW CLOUDS
CLEAR BRIEFLY BY LATE MORNING SAT AS STRONGER SOUTH WINDS
DEVELOP...BEFORE A RENEWED CHANCE OF SHOWERS AND THUNDERSTORMS
RETURNS INT THE AFTERNOON.
AT KPUB...EXPECT PATCHY MVFR MVFR CONDITIONS INTO THE EVENING AND
OVERNIGHT WITH STRONG CONVECTION AND PERIODS OF BRIEF IFR CLOSE
TO THE TERMINAL UNTIL AT LEAST 03Z. OVERNIGHT...STILL LOW THREAT
OF OCCASIONAL -SHRA/-TSRA WITH UNTIL 06Z-09THEN LOWER CLOUDS
SHOULD FINALLY CLEAR BY LATE MORNING SAT AS STRONGER SOUTH WINDS
DEVELOP.
AT KALS...VFR CONDITIONS EXPECTED THE NEXT 24 HRS LOW CHANCE OF
TSRA OVERNIGHT AND THROUGH THE DAY SAT.
&&
.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...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT THU MAY 7 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 212 PM MDT THU MAY 7 2015
CURRENTLY...STEEP LOW LEVEL LAPSE RATES...FAIRLY COLD AIR ALOFT
AND SURFACE CAPES OVER 1000 J/KG HAVE COMBINED TO GENERATE VERY
EFFICIENT HAIL PRODUCING TSRA ACROSS EL PASO COUNTY...WITH 6-8 INCH
DEEP ACCUMULATIONS SLOWING TRAFFIC AND CAUSING DRAINAGE PROBLEMS
OVER THE NORTH SIDE OF COLORADO SPRINGS. TOUGH TO FIND MUCH UPPER
LEVEL FORCING...THOUGH THERE IS A HINT OF A WEAK SHORT WAVE LIFTING
NORTHEASTWARD THROUGH THE FOUR CORNERS IN THE LATEST WATER VAPOR
LOOP. ELSEWHERE ON THE PLAINS...CAPES RUNNING 1000-1500 J/KG....WITH
BEST INSTABILITY SOUTH OF THE ARKANSAS RIVER WHERE STRATUS CLEARED
FASTEST EARLIER THIS MORNING. FOR THE REMAINDER OF THE
AFTERNOON...SVR TSRA WATCH ISSUED FOR PLAINS ALONG AND EAST OF I-25
WITH MAIN THREAT BEING LARGE HAIL...THOUGH ISOLATED CELLS ACROSS LAS
ANIMAS/BACA COUNTIES HAVE SHOWN SOME SUPERCELLULAR CHARACTERISTICS
WITH A LEAST A LOW THREAT OF A TORNADO.
TONIGHT...TSRA MIGRATE EASTWARD THIS EVENING...WITH LATEST HRRR
KEEPING STRONGEST STORMS ALONG THE PALMER DIVIDE AND ACROSS LAS
ANIMAS/BACA COUNTIES THROUGH THE EVENING BEFORE A LOOSELY ORGANIZED
LINE FORMS NEAR THE KS BORDER LATER IN THE EVENING. HRRR ALSO HINTS
AT A NEW ROUND OF CONVECTION ALONG THE I-25 CORRIDOR IN PUEBLO/EL
PASO COUNTIES 05Z-06Z AS OUTFLOW ENHANCED UPSLOPE FLOW PUSHES BACK
WESTWARD. OVERALL...WILL KEEP POPS IN PLACE MOST LOCATIONS THROUGH
THE NIGHT...HIGHEST CHANCES EL PASO/TELLER COUNTIES.
THURSDAY...STILL A FEW LINGERING -SHRA DURING THE MORNING WITH LOW
LEVEL MOISTURE/UPSLOPE AND WEAK WARM ADVECTION LIFT DEVELOPING OVER
THE OLD FRONTAL BOUNDARY. BY AFTERNOON...EXPECT WARM FRONT TO LIE
ALONG THE NM BORDER AROUND MIDDAY BEFORE LIFTING NORTHWARD TOWARD
THE ARK RIVER BY EVENING. ALONG AND NORTH OF THE BOUNDARY...EASTERLY
BL FLOW COMBINED WITH FAIRLY DEEP INSTABILITY WILL LEAD TO ANOTHER
ROUND OF STRONG TO SEVERE THUNDERSTORMS AS CAPES RANGE FROM 1-2K
J/KG AND 0-6KM SHEAR APPROACHES 50 KTS. ELSEWHERE OVER THE MOUNTAINS
AND HIGH VALLEYS...LITTLE CHANGE IN THE PATTERN AS SCT AFTERNOON
TSRA WILL DEVELOP ONCE AGAIN...WITH HIGHEST POPS GENERALLY OVER THE
NORTHERN HALF OF THE AREA. MAX TEMPS LITTLE CHANGED WITH
CLOUDS/MOISTURE/PRECIP PERSISTING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 212 PM MDT THU MAY 7 2015
THERE IS A HIGH DEGREE OF ENSEMBLE SPREAD THROUGH THE EXTENDED
PERIOD WITH ACTIVE WEATHER LOOKING TO CONTINUE FOR THE NEXT
SEVERAL DAYS. CONFIDENCE IN THE FORECAST IS ON THE HIGHER SIDE
THROUGH THE WEEKEND...WITH LESS CONFIDENCE EARLY TO MIDDLE NEXT
WEEK.
FRIDAY NIGHT THROUGH SUNDAY NIGHT...A STRONG UPPER LEVEL LOW
PRESSURE SYSTEM IS FORECAST TO MOVE OUT OF THE DESERT
SOUTHWEST...NORTHEAST ACROSS SOUTHERN COLORADO INTO THE NORTHERN
PLAINS. SEVERAL ROUNDS OF WEATHER ARE EXPECTED WITH THIS STORM
SYSTEM AND PREPARATIONS SHOULD BE MADE FOR MOUNTAIN
SNOWFALL...SEVERE WEATHER ON THE PLAINS AND FLOODING POTENTIAL IN
SATURATED AREAS.
A SHORTWAVE TROUGH WILL BE EJECTING AROUND THE LOW ACROSS
COLORADO FRIDAY NIGHT. EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO
BE ONGOING ACROSS THE REGION. SHEAR AND INSTABILITY WILL BE
SUFFICIENT FOR A FEW STRONG TO SEVERE THUNDERSTORMS FRIDAY
EVENING...ESPECIALLY EAST OF A LA JUNTA TO KIM LINE. STRONG WINDS
AND LARGE HAIL ARE THE PRIMARY THREATS...AND AN ISOLATED TORNADO
IS POSSIBLE. THESE STORMS WILL SHIFT EAST INTO WESTERN KANSAS
THROUGH THE LATE EVENING HOURS. ELSEWHERE...SHOWERS AND
THUNDERSTORMS WILL CONTINUE ACROSS THE MOUNTAINS AND ADJACENT
PLAINS. LOCALLY HEAVY RAINFALL IS POSSIBLE AND SMALL HAIL FRIDAY
EVENING. IF A STRONGER STORM CAN IMPACT TELLER AND EL PASO
COUNTIES...FLASH FLOODING WILL BE POSSIBLE. THIS ACTIVITY SHOULD
CONTINUE THROUGH FRIDAY NIGHT.
THE UPPER LEVEL LOW IS FORECAST TO MOVE NORTHEAST ACROSS SOUTHERN
INTO EASTERN COLORADO ON SATURDAY. SEVERAL CONCERNS AS THE UPPER
SYSTEM EJECTS ACROSS THE AREA...THE POTENTIAL FOR SEVERE WEATHER
ALONG THE KANSAS BORDER...HEAVY RAINFALL WRAPPING AROUND THE
SYSTEM OVER THE PALMER DIVIDE AND INTO THE RAMPART RANGE AND SNOW
LEVELS. ALL OF THESE WEATHER CONCERNS WILL DEPEND ON THE EXACT
STORM PATH. THE NAM AND ECMWF HAVE A MORE FAVORABLE SOUTHERN
SOLUTION...WHILE THE GFS IS SLIGHTLY NORTH AND WOULD LIMIT THE
HEAVY RAINFALL THREAT IN PARTICULAR. AS FOR THE SEVERE WEATHER
THREAT...MODELS ARE IN GOOD AGREEMENT WITH A DRYLINE DEVELOPING
OVER THE EASTERN PLAINS AND TRACKING THROUGH THE AFTERNOON.
CONVECTION IS FORECAST TO DEVELOP ALONG THE DRYLINE DURING THE
AFTERNOON HOURS...AND STORMS THAT DO DEVELOP WILL LIKELY BECOME
SEVERE. THE MAIN QUESTION IS HOW FAR EAST OR WEST THE STORMS
DEVELOP. HAVE A FEELING THE SEVERE WEATHER THREAT WILL BE LIMITED
TO ALONG THE KANSAS BORDER. ELSEWHERE...FLOW BEHIND THE SURFACE
LOW WILL PROVIDE STRONG LOW LEVEL UPSLOPE FLOW OVER THE PALMER
DIVIDE INTO THE RAMPART RANGE. THIS UPSLOPE FLOW COMBINED WITH
ABUNDANT MOISTURE WILL PROVIDE A FOCUS FOR HEAVY RAINFALL ALONG
THE LEE SLOPES OF THE RAMPART RANGE AND PALMER DIVIDE. THESE AREAS
HAVE SEEN HEAVY RAINFALL LATELY AND ARE SATURATED...AND FLOODING
WILL BE POSSIBLE...ESPECIALLY WITH THE ECMWF AND NAM STORM TRACK.
SNOW LEVELS WILL LIKELY BE HIGH THROUGH THE DAY ON SATURDAY WITH
SEVERAL INCHES EXPECTED ABOVE 10 KFT.
THE UPPER LEVEL LOW WILL PULL OFF INTO THE CENTRAL PLAINS SATURDAY
NIGHT INTO SUNDAY. WRAP AROUND FLOW AND SOME MODELS ARE PRODUCING
A TROWAL FEATURE OVER NORTHERN COLORADO KEEPING DECENT
PRECIPITATION ACROSS MUCH OF THE REGION. GFS HAS THIS FEATURE
NORTH...HOWEVER THE ECMWF AND NAM ARE SOUTH AND HAVE THIS FEATURE
IMPACTING THE AREA THROUGH SUNDAY MORNING. COLD AIR WILL BE
FILTERING INTO THE REGION WHICH WILL LIKELY DROP SNOW LEVELS DOWN
TO AROUND 7 KFT SUNDAY MORNING. THIS COULD LEAD TO SNOW ON THE
PALMER DIVIDE AND AN INCH OR TWO OF ACCUMULATION GRASSY SURFACE.
EXPECT MOST AREAS TO SEE CONTINUED SHOWER ACTIVITY IN THE COLD
WRAP AROUND FLOW THROUGHOUT THE DAY ON SUNDAY.
MONDAY THROUGH THURSDAY...THE UPPER SYSTEM WILL BE SHIFTING OFF
TO THE NORTHEAST WITH THE NEXT SYSTEM TAKING SHAPE BY THE MIDDLE
OF THE WEEK. EXPECT CONTINUED SHOWER AND THUNDERSTORM ACTIVITY
EACH AFTERNOON AND EVENING ACROSS THE MOUNTAINS...MOVING OUT IN
THE PLAINS. THE NEXT SYSTEM WILL LIKELY IMPACT THE AREA WEDNESDAY
INTO THURSDAY WITH ANOTHER ROUND OF WIDESPREAD SHOWER AND
THUNDERSTORM ACTIVITY BY THURSDAY. MOZLEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 212 PM MDT THU MAY 7 2015
ISOLD TO SCT TSRA WILL CONTINUE ALL AREAS INTO THE
EVENING...BEST CHANCES AT TAF SITES WILL BE AT KCOS AND KPUB...WITH
STORMS POTENTIALLY PRODUCING LARGE VOLUMES OF HAIL. TS THREAT
GRADUALLY ENDS THIS EVENING...THOUGH SOME -SHRA MAY LINGER PAST 06Z
OVER THE EASTERN MOUNTAINS AND ALONG THE I-25 CORRIDOR. AS LOW LEVEL
MOISTURE SLOSHES BACK WESTWARD OVERNIGHT...EXPECT STRATUS TO
REDEVELOP OVER THE PLAINS WITH IFR CIGS FOR SEVERAL HOURS AROUND
SUNRISE AT KCOS...WHILE MVFR CIGS DEVELOP NEAR KPUB. EXPECT YET MORE
SCT AFTERNOON TSRA ON FRI...WITH A THREAT FOR SEVERE TSRA AT KCOS
AND KPUB AFTER 19Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOZLEY
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1227 AM MDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1223 AM MDT THU MAY 7 2015
QUICK UPDATE TO GRIDDED POP FIELDS TO INCREASE THE CHANCE OF
PRECIPITATION FOR THE REMAINDER OF THE NIGHT. LATEST HRRR KEEPS
ACTIVITY IN THE REGION THROUGH 5 AM THIS MORNING WITH YET ANOTHER
WAVE LIFTING NORTHEAST ACROSS THE REGION. PRECIP AMOUNTS NOT
EXPECTED TO BE AS HEAVY AS EARLIER TODAY...BUT SOILS ARE SATURATED
IN MANY AREAS...SO WILL KEEP A CLOSE EYE ON CELLS...ESPECIALLY AS
THEY APPROACH POPULATED AREAS.
UPDATE ISSUED AT 940 PM MDT WED MAY 6 2015
HAVE INCREASED THE PRECIPITATION COVERAGE THROUGH TONIGHT AS
THERE CONTINUES TO BE SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
UPSTREAM. IT APPEARS THAT THERE WILL CONTINUE TO BE WEAK EMBEDDED
DISTURBANCES IN THE SOUTHWEST FLOW OVER THE FORECAST AREA. THIS
WILL BE ENOUGH TO KEEP ISOLATED TO SCATTERED SHOWERS AT TIMES
THROUGHOUT THE NIGHT...GRADUALLY WINDING DOWN TOWARDS MORNING. THE
SOUTHERN PORTION HAS CONTINUED TO BE MORE ACTIVE THAN EXPECTED
WITH ENERGY STREAMING OVER THE FOUR CORNERS AT THIS TIME. THIS
SHOULD PERSIST FOR THE NEXT FEW HOURS. THEREFORE THE FORECAST WILL
SEE THE BIGGEST CHANGES THERE.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED MAY 6 2015
THE STRONG LOW THAT MOVED OVER THE AREA LAST NIGHT AND THIS
MORNING WILL CONTINUE MOVING INTO THE HIGH PLAINS TONIGHT.
NW AND CENTRAL CO AND NE UT WILL BE BENEATH THE NW FLOW ALOFT
ON THE WEST SIDE OF THE STORM...WHERE UNSTABLE AND MOIST
CONDITIONS WILL CONTINUE TO PRODUCE RAIN SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE AREA. A FEW STORMS HAVE BEEN STRONG ENOUGH TO
PRODUCE SMALL HAIL AND HEAVY RAIN. A WEAK SHORTWAVE TROUGH MOVING
OVER NORTHWEST CO AND NE UT WILL ALSO AS SOME SUPPORT FOR
CONVECTION UNTIL ABOUT 03Z THIS EVENING. SUBSIDENCE AND GRADUALLY
DRIER AIR WILL FILTER INTO EASTER UT...AND NORTHWEST AND CENTRAL
CO AFTER MIDNIGHT. OVER SW CO...THE HRRR AND NAM12 SHOW ANOTHER
WEAK SHORTWAVE WILL BRING INCREASING CLOUDS AND ISOLATED
PRECIPITATION LATE TONIGHT.
THURSDAY MORNING...IN SOUTH FLOW A WEAK WAVE WORKS THROUGH THE
FOUR CORNERS REGION. AVAILABLE MOISTURE WILL BE DIMINISHING THERE
SO ONLY ISOLATED SHOWERS ARE FORECASTED ACROSS THE SOUTH FAVORING
THE SAN JUANS. DEEPER MOISTURE REMAINS ACROSS THE NORTH THURSDAY
ALONG WITH SOME WEAK FRONTAL FORCING. MARGINAL AFTERNOON
INSTABILITY WILL LIMIT THUNDERSTORM COVERAGE MAINLY OVER MTNS
NORTH OF I-70.
THURSDAY NIGHT DRIER SW FLOW INVADES LIMITING NIGHTTIME SHOWERS
TO NEAR THE CONTINENTAL DIVIDE. TEMPERATURES REMAIN NEAR NORMAL.
THE NEXT STRONGER PACIFIC LOW SINKS THROUGH CALIFORNIA ON THURSDAY
THEN BEGINS TO AMBLE INLAND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED MAY 6 2015
A HIGHLY AMPLIFIED PROGRESSIVE PATTERN CONTINUES THROUGH THESE
PERIODS. ONE STRONG UPPER LOW WILL PASS ON SATURDAY BRINGING A
BLAST OF NORTHERN AND MOUNTAIN SNOW. TWO OTHER TROUGHS CURRENTLY
ARE TIMED TO PASS MID TO LATE NEXT WEEK.
FRIDAY THE UPPER LOW WITH A MODIFYING BUT IMPRESSIVE -26C COLD
CORE WORKS NORTH OF LAS VEGAS TO SOUTHCENTRAL UTAH FRIDAY NIGHT
AND THROUGH THE FORECAST AREA ON SATURDAY. THE THERMAL RIDGE
BLOSSOMS OVER THE FORECAST AREA FRIDAY AND HAVE RAISED
TEMPERATURES CLOSER TO THE WARMER NAM GUIDANCE. A 70KT JET NOSE
POKES INTO SE UTAH IN THE AFTERNOON AND RAKES THE SOUTH OVERNIGHT.
COOL ADVECTION ALOFT BEGINS TO DESTABILIZE BUT AVAILABLE MOISTURE
IS LIMITED AND MAINLY ACROSS THE NORTH.
SATURDAY THE POTENTIAL VORTICITY CENTER RAKES THE NORTH AS THE
JET WRAPS UP THE FRONT RANGE. FRONTAL FORCING SEEN IN THE PARK
RANGE BY THE AFTERNOON. THE BEST SHOWER COVERAGE WILL BE OVER THE
NORTHERN MOUNTAINS BUT WILL EXTEND INTO THE CENTRAL CO MTNS. SNOW
LEVELS DROP TO AROUND 8KFT...AND WILL BRIEFLY BE LOWER IN
STRONGER CONVECTION. THE LOW LIFTS THROUGH THE NORTHERN PLAINS
SATURDAY NIGHT THROUGH SUNDAY. WRAP- AROUND MOISTURE WILL CONTINUE
TO PRODUCE SHOWERS FAVORING THE NORTH. SUNDAY...SNOW LEVELS LOWER
INTO THE NORTHERN VALLEYS WITH 700MB TEMPS AT -4C THERE.
SIGNIFICANT SNOWFALL IS EXPECTED FOR THIS WEEKEND FOR THE EASTERN
UINTAS AND THE COLORADO MOUNTAINS FROM WYOMING DOWN INTO THE NW
SAN JUANS. TRAVEL THROUGH THESE MOUNTAINS COULD BE HAZARDOUS THIS
WEEKEND. COLDER THAN NORMAL TEMPERATURES EXPECTED ACROSS THE
REGION THROUGH SUNDAY NIGHT. HIGH VALLEY FREEZES ARE POSSIBLE.
MONDAY WARM ADVECTION BEGINS AS A RIDGE BUILDS IN FROM THE WEST.
FLOW ALOFT QUICKLY SWITCHES BACK TO SW AND INCREASES INTO THE NEW
WEEK AS THE NEXT TROUGH WORKS INTO THE PACIFIC NW ON TUESDAY AND
THE GREAT BASIN ON WEDNESDAY. AN ASSOCIATED ZONAL JET FROM CENTRAL
CALIFORNIA INTRUDES INTO THE NORTHERN-CENTRAL FORECAST AREA ON
WEDNESDAY BEGINNING THE CHANCE OF MAINLY RAIN SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1145 PM MDT WED MAY 6 2015
SCATTERED -SHRA WITH A FEW -TSRA WILL OCCUR DURING THE OVERNIGHT
HOURS...ESPECIALLY SW AND WEST CENTRAL COLORADO AS A SHORT WAVE
LIFTS ACROSS THIS PORTION TONIGHT. AFTER A MORNING LULL WITH
ISOLATED -SHRA...SCATTERED TSRA WILL DEVELOP ONCE AGAIN WITH THE
PRIMARY FOCUS OVER NW COLORADO AND THE UINTA MOUNTAINS. DIURNAL
STORMS WILL BE LESS NUMEROUS OVER SW COLORADO. SMALL HAIL AND
GUSTY WINDS TO 30KTS WILL BE POSSIBLE WITH THE STRONGEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...JDC
SHORT TERM...CC/JOE
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1145 PM MDT WED MAY 6 2015
.UPDATE...
ISSUED AT 940 PM MDT WED MAY 6 2015
HAVE INCREASED THE PRECIPITATION COVERAGE THROUGH TONIGHT AS
THERE CONTINUES TO BE SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
UPSTREAM. IT APPEARS THAT THERE WILL CONTINUE TO BE WEAK EMBEDDED
DISTURBANCES IN THE SOUTHWEST FLOW OVER THE FORECAST AREA. THIS
WILL BE ENOUGH TO KEEP ISOLATED TO SCATTERED SHOWERS AT TIMES
THROUGHOUT THE NIGHT...GRADUALLY WINDING DOWN TOWARDS MORNING. THE
SOUTHERN PORTION HAS CONTINUED TO BE MORE ACTIVE THAN EXPECTED
WITH ENERGY STREAMING OVER THE FOUR CORNERS AT THIS TIME. THIS
SHOULD PERSIST FOR THE NEXT FEW HOURS. THEREFORE THE FORECAST WILL
SEE THE BIGGEST CHANGES THERE.
&&
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED MAY 6 2015
THE STRONG LOW THAT MOVED OVER THE AREA LAST NIGHT AND THIS
MORNING WILL CONTINUE MOVING INTO THE HIGH PLAINS TONIGHT.
NW AND CENTRAL CO AND NE UT WILL BE BENEATH THE NW FLOW ALOFT
ON THE WEST SIDE OF THE STORM...WHERE UNSTABLE AND MOIST
CONDITIONS WILL CONTINUE TO PRODUCE RAIN SHOWERS AND THUNDERSTORMS
OVER MUCH OF THE AREA. A FEW STORMS HAVE BEEN STRONG ENOUGH TO
PRODUCE SMALL HAIL AND HEAVY RAIN. A WEAK SHORTWAVE TROUGH MOVING
OVER NORTHWEST CO AND NE UT WILL ALSO AS SOME SUPPORT FOR
CONVECTION UNTIL ABOUT 03Z THIS EVENING. SUBSIDENCE AND GRADUALLY
DRIER AIR WILL FILTER INTO EASTER UT...AND NORTHWEST AND CENTRAL
CO AFTER MIDNIGHT. OVER SW CO...THE HRRR AND NAM12 SHOW ANOTHER
WEAK SHORTWAVE WILL BRING INCREASING CLOUDS AND ISOLATED
PRECIPITATION LATE TONIGHT.
THURSDAY MORNING...IN SOUTH FLOW A WEAK WAVE WORKS THROUGH THE
FOUR CORNERS REGION. AVAILABLE MOISTURE WILL BE DIMINISHING THERE
SO ONLY ISOLATED SHOWERS ARE FORECASTED ACROSS THE SOUTH FAVORING
THE SAN JUANS. DEEPER MOISTURE REMAINS ACROSS THE NORTH THURSDAY
ALONG WITH SOME WEAK FRONTAL FORCING. MARGINAL AFTERNOON
INSTABILITY WILL LIMIT THUNDERSTORM COVERAGE MAINLY OVER MTNS
NORTH OF I-70.
THURSDAY NIGHT DRIER SW FLOW INVADES LIMITING NIGHTTIME SHOWERS
TO NEAR THE CONTINENTAL DIVIDE. TEMPERATURES REMAIN NEAR NORMAL.
THE NEXT STRONGER PACIFIC LOW SINKS THROUGH CALIFORNIA ON THURSDAY
THEN BEGINS TO AMBLE INLAND THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED MAY 6 2015
A HIGHLY AMPLIFIED PROGRESSIVE PATTERN CONTINUES THROUGH THESE
PERIODS. ONE STRONG UPPER LOW WILL PASS ON SATURDAY BRINGING A
BLAST OF NORTHERN AND MOUNTAIN SNOW. TWO OTHER TROUGHS CURRENTLY
ARE TIMED TO PASS MID TO LATE NEXT WEEK.
FRIDAY THE UPPER LOW WITH A MODIFYING BUT IMPRESSIVE -26C COLD
CORE WORKS NORTH OF LAS VEGAS TO SOUTHCENTRAL UTAH FRIDAY NIGHT
AND THROUGH THE FORECAST AREA ON SATURDAY. THE THERMAL RIDGE
BLOSSOMS OVER THE FORECAST AREA FRIDAY AND HAVE RAISED
TEMPERATURES CLOSER TO THE WARMER NAM GUIDANCE. A 70KT JET NOSE
POKES INTO SE UTAH IN THE AFTERNOON AND RAKES THE SOUTH OVERNIGHT.
COOL ADVECTION ALOFT BEGINS TO DESTABILIZE BUT AVAILABLE MOISTURE
IS LIMITED AND MAINLY ACROSS THE NORTH.
SATURDAY THE POTENTIAL VORTICITY CENTER RAKES THE NORTH AS THE
JET WRAPS UP THE FRONT RANGE. FRONTAL FORCING SEEN IN THE PARK
RANGE BY THE AFTERNOON. THE BEST SHOWER COVERAGE WILL BE OVER THE
NORTHERN MOUNTAINS BUT WILL EXTEND INTO THE CENTRAL CO MTNS. SNOW
LEVELS DROP TO AROUND 8KFT...AND WILL BRIEFLY BE LOWER IN
STRONGER CONVECTION. THE LOW LIFTS THROUGH THE NORTHERN PLAINS
SATURDAY NIGHT THROUGH SUNDAY. WRAP- AROUND MOISTURE WILL CONTINUE
TO PRODUCE SHOWERS FAVORING THE NORTH. SUNDAY...SNOW LEVELS LOWER
INTO THE NORTHERN VALLEYS WITH 700MB TEMPS AT -4C THERE.
SIGNIFICANT SNOWFALL IS EXPECTED FOR THIS WEEKEND FOR THE EASTERN
UINTAS AND THE COLORADO MOUNTAINS FROM WYOMING DOWN INTO THE NW
SAN JUANS. TRAVEL THROUGH THESE MOUNTAINS COULD BE HAZARDOUS THIS
WEEKEND. COLDER THAN NORMAL TEMPERATURES EXPECTED ACROSS THE
REGION THROUGH SUNDAY NIGHT. HIGH VALLEY FREEZES ARE POSSIBLE.
MONDAY WARM ADVECTION BEGINS AS A RIDGE BUILDS IN FROM THE WEST.
FLOW ALOFT QUICKLY SWITCHES BACK TO SW AND INCREASES INTO THE NEW
WEEK AS THE NEXT TROUGH WORKS INTO THE PACIFIC NW ON TUESDAY AND
THE GREAT BASIN ON WEDNESDAY. AN ASSOCIATED ZONAL JET FROM CENTRAL
CALIFORNIA INTRUDES INTO THE NORTHERN-CENTRAL FORECAST AREA ON
WEDNESDAY BEGINNING THE CHANCE OF MAINLY RAIN SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1145 PM MDT WED MAY 6 2015
SCATTERED -SHRA WITH A FEW -TSRA WILL OCCUR DURING THE OVERNIGHT
HOURS...ESPECIALLY SW AND WEST CENTRAL COLORADO AS A SHORT WAVE
LIFTS ACROSS THIS PORTION TONIGHT. AFTER A MORNING LULL WITH
ISOLATED -SHRA...SCATTERED TSRA WILL DEVELOP ONCE AGAIN WITH THE
PRIMARY FOCUS OVER NW COLORADO AND THE UINTA MOUNTAINS. DIURNAL
STORMS WILL BE LESS NUMEROUS OVER SW COLORADO. SMALL HAIL AND
GUSTY WINDS TO 30KTS WILL BE POSSIBLE WITH THE STRONGEST STORMS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...EH
SHORT TERM...CC/JOE
LONG TERM...JOE
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1115 PM MDT WED MAY 6 2015
.UPDATE...
ISSUED AT 915 PM MDT WED MAY 6 2015
INCREASED POPS FOR TONIGHT ACROSS THE CONTDVD WITH EMBEDDED SHORT
WAVE LIFTING OUT OF THE FOUR CORNERS AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 345 PM MDT WED MAY 6 2015
CURRENTLY...UPPER LOW PUSHING SLOWLY INTO WRN NEB THIS
AFTERNOON...WHILE WEAKER SHORT WAVE ENERGY WAS DRIFTING NORTH INTO
SOUTHERN COLORADO FROM NM. WITH LACK OF MUCH BL/SURFACE WLY FLOW AND
MOIST GROUND...DEWPOINTS HAVE HELD IN THE MID TO UPPER 40S ACROSS
THE I-25 CORRIDOR AND IN THE LOWER 50S FARTHER EAST NEAR THE KS
BORDER. MESO-ANALYSIS SUGGESTS MIXED LAYER CAPES OVER 1000 J/K
ACROSS THE PLAINS ALONG THE ARKANSAS RIVER THIS AFTERNOON WHERE
SKIES HAVE CLEARED...WITH VALUES 500-1000 J/K FARTHER WEST OVER THE
MOUNTAINS AND VALLEYS. STRONGEST STORMS SO FAR TODAY HAVE BEEN OVER
EL PASO COUNTY...THOUGH ADDITIONAL CELLS HAVE BEGUN DEVELOPING
SOUTHWARD ALONG AND WEST OF I-25 AS OF 2030Z.
TONIGHT...LATEST HRRR BRINGS CONVECTION OFF THE MOUNTAINS AND ACROSS
THE PLAINS LATE THIS AFTERNOON AND EARLY THIS EVENING AS WEAK NM
SHORTWAVE MOVES NORTH...WITH PERHAPS A LOOSELY ORGANIZED LINE
DEVELOPING 00Z-01Z AS STORMS REACH THE KS BORDER. SHEAR IS FAIRLY
WEAK...SO EXPECT MAINLY BRIEF HEAVY RAIN AND SMALL HAIL WITH CELLS
INTO THE EVENING. NAM/GFS END MOST CONVECTION THIS EVENING...WHILE
HRRR DEVELOPS SOME WEAK SHOWERS OVER THE EASTERN MOUNTAINS AND EL
PASO COUNTY 06Z-07Z. WILL GRADUALLY TAPER OFF POPS DURING THE
EVENING...KEEPING SOME LOW CHANCES AFTER MIDNIGHT MAINLY OVER THE
MOUNTAINS AND NORTH OF THE ARKANSAS RIVER. WEAK COLD FRONT WILL DROP
SOUTH THROUGH THE PLAINS LATE TONIGHT...WITH A GRADUALLY SHIFT TO N-
NE WINDS ALONG AND EAST OF I-25 BY SUNRISE WED. MAY SEE SOME LOWER
CLOUDS BEHIND THE BOUNDARY EARLY WED MORNING...ESPECIALLY NEAR THE
KS BORDER WHERE LOW LEVEL MOISTURE WILL BE DEEPER.
THURSDAY...OLD UPPER TROUGH LIFTS INTO THE NORTHERN HIGH PLAINS
WHILE NEW UPPER LOW TAKING SHAPE ACROSS CENTRAL CALIFORNIA. AS A
RESULT...BROAD SOUTHWEST FLOW WILL GRADUALLY STRENGTHEN ACROSS THE
AREA...WHILE SURFACE COLD FRONT BECOMES STATIONARY ALONG THE NM
EARLY IN THE DAY BEFORE LIFTING NORTHWARD TO SOMEWHERE BETWEEN THE
THE ARKANSAS RIVER AND PALMER DIVIDE BY EVENING. BEST BET FOR STORMS
WILL BE NORTH OF THE BOUNDARY...WHERE LOW LEVEL MOISTURE POOLS AND
CAPES CLIMB TOWARD 1000 J/KG. SEVERE THREAT LOOKS FAIRLY LOW AS 0-
6KM SHEAR STAYS BELOW 40 KTS...THOUGH A COUPLE STRONG STORMS WITH
BRIEF HEAVY RAIN AND SMALL HAIL WILL BE LIKELY. ELSEWHERE...ISOLATED
TO SCATTERED CONVECTION LOOKS POSSIBLE...THOUGH INSTABILITY WILL BE
FAIRLY LOW...LIMITING STORM INTENSITY. MAX TEMPS WILL COOL JUST
SLIGHTLY ACROSS THE PLAINS BEHIND THE FRONT...WITH LITTLE CHANGE
ELSEWHERE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 PM MDT WED MAY 6 2015
...ACTIVE PATTERN THROUGH AT LEAST SUNDAY...
.FRIDAY...DISTURBANCE ROTATES AROUND THE UPPER LOW OVER NEVADA AND
WILL MOVE INTO THE REGION FROM THE SOUTHWEST. HIGH PRESSURE OVER
THE NORTHERN HIGH PLAINS WILL MAINTAIN UPSLOPE FLOW OVER THE
REGION. CONCEPTUALLY...THIS PATTERN CAN LEAD TO SEVERE CONVECTIVE
WEATHER ON THE PLAINS. MAIN CHALLENGE WILL BE THE AMOUNT OF
INSTABILITY AND LOW LEVEL MOISTURE. NAM HAS MORE COLD AIR OVER THE
REGION...WITH THE ATMOSPHERE REMAINING STABLE. THE GFS HAS THE
UPSLOPE FURTHER NORTH...AND BUFKIT SOUNDINGS SHOW THE LOW LEVEL
MOISTURE MIXING OUT OVER MUCH OF THE PLAINS...ESPECIALLY SOUTH OF
HIGHWAY 50. SUSPECT THE AMOUNT OF LOW LEVEL MOISTURE WILL BE A
COMPROMISE BETWEEN THE GFS AND NAM. THERE IS THE POTENTIAL FOR A
REGION OF HIGHER CAPE NEAR THE FRONT OVER THE EASTERN PLAINS.
CURRENTLY SPC DAY 3 OUTLOOK HAS SEVERE CONVECTION STAYING EAST OF
COLORADO. THIS IS A GOOD CALL GIVEN THE CURRENT MODEL OUTPUT WHICH
TENDS TO KEEP THE ATMOSPHERE STABLE.
.SATURDAY AND SUNDAY...UPPER LOW MOVES ACROSS COLORADO.
INTERESTING FORECAST FOR BOTH DAYS. ON SATURDAY...THERE WILL BE
NO SHORTAGE OF SHEAR AVAILABLE FOR SEVERE CONVECTIVE WEATHER. NAM
IS FURTHEST SOUTH OF THE UPPER LOW AND IT HAS THE MOST IMPRESSIVE
SHEAR. MAIN CHALLENGE WITH NAM SOLUTION WILL BE THE AMOUNT OF
INSTABILITY AS MODEL SOUNDINGS SHOW A GENERALLY STABLE ATMOSPHERE.
GFS AND EC TEND TO BE FURTHER NORTH...AND ARE PREFERRED. THESE
SOLUTIONS WOULD TEND TO MIX OUT THE LOW LEVEL MOISTURE OVER MUCH
OF THE PLAINS...ESPECIALLY SOUTH OF HIGHWAY 50. CURRENT THINKING
IS THE BEST CHANCES FOR STRONG TO SEVERE CONVECTION WILL BE IN
KIOWA AND EL PASO COUNTIES...BUT WILL HAVE TO WATCH FOR FURTHER
SOUTH SOLUTION. ON SUNDAY AS THE UPPER LOW LIFTS TO THE
NORTHEAST...UNSEASONABLY COLD AIR WILL MOVE SOUTHWARD INTO THE
REGION. EC AND GFS STILL HINT AT THE TROWAL MAKING INTO EL PASO
AND TELLER COUNTIES. IF THE TROWAL REACHES THIS FAR SOUTH...THEN A
PERIOD OF SNOW WITH GUSTY NORTH WINDS WILL OCCUR. LATER IN THE
DAY...THE GFS...AND TO A LESSER EXTENT...THE EC HAVE A SECONDARY
DISTURBANCE MOVING IN FROM THE NORTHWEST. BOTH MODELS HAVE
NORTHEAST UPSLOPE DEVELOP ALONG THE EASTERN MOUNTAINS WITH A
PERIOD OF SNOW...AS SNOW LEVELS AS LOW AS 6000 FEET. GIVEN THIS IS
STILL ON DAY 4...DID NOT HIT THIS SOLUTION HARD IN THE GRIDS.
.MONDAY THROUGH WEDNESDAY...AS THE UPPER LOW MOVES TO THE
NORTHEAST...A SHORTWAVE RIDGE BUILDS INTO THE REGION ON MONDAY. EC
AND GFS HINT AT ANOTHER DISTURBANCE MOVING INTO THE REGION ON
TUESDAY OR WEDNESDAY. MODELS CURRENTLY SUGGEST THE BEST LOW LEVEL
MOISTURE WILL MOVE EAST OF THE REGION...WITH CONVECTION NOT BEING
VERY STRONG. . --PGW--
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1115 PM MDT WED MAY 6 2015
MAINLY VFR CONDITIONS EXPECTED AT COS AND PUB OVER THE NEXT 24
HOURS. OUTFLOW FROM EVENING STORMS ACROSS NORTHEASTERN COLORADO
WILL SEND A WEAK BOUNDARY ACROSS THE FAR SE PLAINS THROUGH THE
OVERNIGHT HOURS. GENERALLY WEAK NORTHERLY WINDS OVERNIGHT BECOME
WEAK UPSLOPE EARLY THURSDAY MORNING WITH MVFR AND LOCAL IFR CIGS
POSSIBLE NEAR THE HIGHER TERRAIN WEST OF COS AND PUB. SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOP ACROSS THE HIGHER TERRAIN AFT
18Z WITH THE BEST CHANCES OF STORMS AFFECTING THE TERMINALS BEING
AT COS. BRIEF MVFR CONDITIONS IN HEAVY RAIN...GUSTY WINDS AND
SMALL HAIL WILL BE POSSIBLE IF THE STORMS MOVE ACROSS THE TERMAINALS.
VFR CONDITIONS EXPECTED AT ALS OVER THE NEXT 24 HOURS...WITH STORM
POSSIBLE OVER AND NEAR THE HIGHER TERRAIN WEST AND EAST OF THE AREA.
BREEZY SOUTHERLY WINDS EXPECTED IN THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MW
SHORT TERM...PETERSEN
LONG TERM...PGW
AVIATION...MW
AREA FORECAST DISCUSSION
NWS TAUNTON MA
730 PM EDT FRI MAY 8 2015
.SYNOPSIS...
THE WEEKEND WILL FEATURE ABOVE NORMAL TEMPERATURES...ESPECIALLY
ON SUNDAY WITH MAINLY DRY WEATHER. AN APPROACHING COLD FRONT LOOKS
TO BRING A ROUND OR TWO OF SCATTERED SHOWERS AND THUNDERSTORMS
EARLY NEXT WEEK. SUBTROPICAL STORM ANA SHOULD PASS SOUTH OF THE
REGION DURING TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
7 PM UPDATE...
VISIBLE SATELLITE SHOWING LOW CLOUDS AND FOG IMMEDIATELY OFFSHORE
OF S NEW ENGLAND BEGINNING TO CREEP-IN WITH THE SURFACE WINDS.
TRENDING THIS ACTIVITY IS TRICKY. USED A BLEND OF THE HRRR WHICH
LOOKS TO BE HANDLING THE PRESENT TRENDS FAIRLY WELL ALONG WITH
FORECAST DEWPOINT DEPRESSIONS TO DISTINGUISH WHERE FOG WOULD BE
LIKELY. CORRELATED THIS WITH SREF PROBABILITIES FOR CEILING AND
VISIBILITIES...AS WELL AS WITH MOS-GUIDANCE.
SO OVERALL OVER THE NEXT HOUR OR TWO COASTAL COMMUNITIES SHOULD
BECOME SOCKED IN AS DIURNAL MIXING DIMINISHES AND SURFACE WINDS
ADVECT THE OFFSHORE MOIST AIRMASS INTO S NEW ENGLAND. WILL KEEP
WITH THE PRESENT DENSE FOG ADVISORY. IT IS QUITE PLAUSIBLE IT WILL
NEED TO BE EXPANDED TO ALL OF E-COASTAL MA AND THERE IS ALSO THE
POSSIBILITY OF FURTHER EXTENDING IT INTO THE INTERIOR. NOT A LOT
OF CONFIDENCE ON THE EVOLUTION OF THE ANTICIPATED SOUPY CONDITIONS.
DOES NOT LOOK LIKE IT WILL BURN OFF QUITE QUICKLY DURING THE
MORNING HOURS. PATCHY DRIZZLE POSSIBLE ALONG THE COAST.
&&
.SHORT TERM /SATURDAY NIGHT/...
SATURDAY...
THE MAIN UNCERTAINTY IS HOW QUICKLY STRATUS AND FOG WILL
DISSIPATE...AS BACKDOOR COLD FRONT SLOWLY MIXES OUT. EXPECT
INTERIOR LOCATIONS TO QUICKLY BREAK OUT INTO PARTIAL SUNSHINE
DURING MID/LATE MORNING...BUT THE PROCESS WILL BE SLOWER ALONG
THE S COAST AND IT MAY TAKE UNTIL THE AFTERNOON AS LOW LEVEL FLOW
TURNS SOUTHERLY. IN FACT...IT IS POSSIBLE CLOUDS LINGER ACROSS
THE ISLANDS FOR MOST OF THE DAY.
HIGH TEMPS SHOULD REACH WELL INTO THE 70S IN THE INTERIOR WITH
SOME LOWER 80S POSSIBLE CT VALLEY. TEMPS TRICKY CLOSER TO THE
COAST AND WILL DEPEND ON HOW QUICKLY LOW CLOUDS AND FOG BURN OFF.
WE ARE KEEPING HIGHS IN THE 60S ALONG THE S COAST WITH LOWER 70S
JUST INLAND FROM THE COAST.
SATURDAY NIGHT...
CONTINUED LIGHT ONSHORE FLOW AND ABUNDANT LOW LEVEL MOISTURE WILL
RESULT IN STRATUS AND AREAS OF FOG REDEVELOPING ALONG THE COAST
IN THE EVENING THEN EXPANDING INTO THE INTERIOR. FOG WILL BE MOST
PREVALENT ALONG THE S COAST. IT WILL BE A MILD NIGHT WITH MINS
DROPPING INTO THE MID AND UPPER 50S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
*/ HIGHLIGHTS...
* WILL KEEP IT MOSTLY WARM AND DRY INTO MONDAY
* MARINE STRATUS / FOG HANGING ALONG THE COAST
* SWEEPING COLD FRONT AHEAD OF WHICH ANA LIFTS NE ON TUESDAY
* COOL AND DRY FOR THE REMAINDER OF THE WEEK
*/ DISCUSSION...
LIKE AN ODD COUPLE...ANA AND THE MID-LATITUDE TROUGH MOVE TOGETHER
BUT LOOK TO REMAIN APART IN PROXIMITY TO S NEW ENGLAND FOR THE EARLY-
WEEK FORECAST TIMEFRAME. AS ALLUDED TO YESTERDAY THE NEIGHBORING OF
THE TWO MAY RESULT IN LITTLE IN THE WAY OF OUTCOMES ACROSS OUR AREA.
JUST NOT BRINGING THE LOVE OF RAINFALL WE SO DESPERATELY NEED AS WE
ARE IN ABNORMALLY-DRY CONDITIONS. WILL GO INTO MORE DETAIL BELOW...
FORECAST CONSENSUS HAS ANA WOBBLING INTO THE CAROLINAS OVER THE WEEK-
END THEN SWEEPING NE FROM THE NC/VA BORDER OUT OVER THE 40N/70W OVER
THE EARLY-WEEK AHEAD OF THE MID-LATITUDE TROUGH. DO NOT FAVOR THE
08.12Z GFS. WITH ANA FEEL THE ATTENDANT COUNTERCLOCKWISE ROTATION
SHOULD YIELD LOCALIZED RIDGE ENHANCEMENT INTO S NEW ENGLAND. EXPECT
SUNDAY-MONDAY TO BE MOSTLY DRY AS BETTER MOISTURE/INSTABILITY/LIFT
REMAIN N OF OUR REGION ALONG A NEARLY-STATIONARY FRONTAL BOUNDARY.
CAN NOT RULE SUBSEQUENT SHOWER/THUNDERSTORM ACTIVITY TO DRIFT S INTO
N MA. CONTINUED LOW-CONFIDENCE SEVERE. PERHAPS SOME GUSTY WINDS WITH
INVERTED-V PROFILES SUGGESTED VIA BUFKIT. MAIN CONCERN IS HEAVY RAIN
WITH PWATS EXCEEDING 1.5-INCHES AND POTENTIAL SLOW-MOVING / TRAINING
ACTIVITY. MEANWHILE ALONG THE S/SE-COAST BENEATH AFORMENTIONED RIDGE
ENHANCEMENT LIKELY TO SEE CONTINUED MARINE STRATUS / FOG RESULTING
IN SOUPY-COOL CONDITIONS AT TIMES. SO BETWEEN THE POTENTIAL TO THE N
AND TO THE S...ABOVE-AVERAGE TEMPERATURES AND DRY CONDITIONS ARE
FAVORED.
BETTER CHANCES FOR WET-WEATHER ACROSS S NEW ENGLAND WILL BE AROUND
TUESDAY AS THE MID-LATITUDE TROUGH AND ATTENDANT COOL FRONT SWEEP
TO THE E AS ANA LIFTS TO THE NE OUT AHEAD. A COMBINATION OF DEEP-
LAYER MOISTURE ALONG WITH SOME WEAK INSTABILITY AND SHEAR WITHIN
THE WARM- SECTOR LOOK TO BE PRESENT. BUT WHETHER THERE IS ENOUGH
FORCING OR RATHER IF MARINE STRATUS / FOG TURNS OUT TO BE A CRUX
THERE IS JUST NO CERTAINTY. LATELY THERE HAS BEEN CONSISTENCY IN
THAT LITTLE IF ANY OUTCOMES ARISE AS S NEW ENGLAND FINDS ITSELF
BETWEEN TWO AREAS OF LIFT SUBSEQUENTLY RESULTING IN SINKING
MOTIONS AS INFERRED PER BUFKIT PROFILES. A WOBBLE OR SHIFT IN THE
FORECAST IS PLAUSIBLE SO WILL KEEP WITH CHANCE POPS. THINKING ANY
OUTCOMES WILL BE MOSTLY SHOWERY. NOT EVEN CERTAIN OF CONVECTIVE
THREATS ESPECIALLY IF COOL- FRONTAL PASSAGE IS DURING THE MORNING
PERIOD AS SUGGESTED PER THE CONSENSUS FORECAST. FAVOR THE 08.0Z
ECMWF WITH THIS FORECAST.
ENSEMBLE AND DETERMINISTIC FORECAST TRENDS IN AGREEMENT FOR THE LATE-
WEEK PERIOD. COOLER AIRMASS SETTLES ACROSS THE REGION USHERED BY NW-
FLOW. SEASONABLE CONDITIONS BENEATH HIGH PRESSURE WITH SOME CONCERN
OF FROST FOR THURSDAY AND FRIDAY MORNING. BY WEEKEND HIGH PRESSURE
SETTLES E ALONG THE W-PERIPHERY OF WHICH SW-FLOW WOULD LIKELY ADVECT
WARM-MOIST CONDITIONS BACK NORTHWARD. HOW LONG THE WARM-DRY WEATHER
WILL LAST IS UNDER SOME SCRUTINY. ANOTHER WET-WEATHER DISTURBANCE IS
POSSIBLE AS QUICKLY AS THE WEEKEND...THOUGH ENSEMBLES SIGNAL AT AN
IMPACT OVER THE EARLY-WEEK PERIOD THE FOLLOWING WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH FRIDAY/...
TONIGHT...MODERATE CONFIDENCE.
WIDESPREAD IFR-VLIFR WITH LOW-STRATUS / FOG. EXPANSION E/NE WITH
THE SURFACE WINDS. 1/2SM FG VV002 FOR COASTAL TERMINALS...LESSER
IMPACTS INLAND MVFR-IFR BUT CAN NOT RULE OUT LOWER CONDITIONS FOR
IMMEDIATE INTERIOR TERMINALS AWAY FROM THE COAST. -DZ POSSIBLE
WITH DENSE FOG.
SATURDAY...MODERATE CONFIDENCE.
IFR/LIFR STRATUS AND FOG WILLBURN OFF DURING THE MORNING IN THE
INTERIOR...BUT IT MAY TAKE UNTIL THE AFTERNOON ALONG THE S COAST.
TIMING OF IMPROVING CONDITIONS UNCERTAIN AND PARTS OF THE S COAST
AND ESPECIALLY THE ISLANDS MAY NOT COMPLETELY CLEAR WITH ONSHORE
FLOW.
SATURDAY NIGHT...MODERATE CONFIDENCE.
IFR/LIFR STRATUS AND FOG REDEVELOPING ALONG THE COAST AND
EXPANDING INLAND ACROSS SNE WITH LOCALLY DENSE FOG NEAR THE S
COAST.
KBOS TAF...MODERATE CONFIDENCE IN TAF. CONFIDENT CONDITIONS WILL
LOWER BELOW IFR DURING THE EVENING. ENOUGH CONFIDENCE TO PREVAIL
1/2SM FG VV002 FOR A PROLONGED PERIOD OF TIME.
KBDL TAF...MODERATE CONFIDENCE IN TAF. WHILE IFR IS POSSIBLE...HAVE
GREATER CONFIDENCE OF MVFR CONDITIONS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY INTO MONDAY...MODERATE CONFIDENCE.
VFR. BREEZY SW-FLOW. IFR-LIFR MARINE STRATUS / FOG ALONG S/SE-
SHORELINE TERMINALS...ENCROACHING INTO THE INTERIOR DURING THE
OVERNIGHT INTO MORNING PERIODS. -DZ POSSIBLE WITH STRATUS / FOG.
LOW CONFIDENCE -SHRA / TSRA OVER N MA FOR THE PERIOD.
TUESDAY...LOW CONFIDENCE.
SWEEPING COOL FRONT AHEAD OF WHICH ANA LIFTS NE. MIX OF LOW-END VFR
DOWN TO IFR CIGS. LOWEST CONDITIONS EXPECTED ALONG COAST. BREEZY SW-
WINDS. SCT -SHRA EXPECTED. LOW CONFIDENCE TSRA.
WEDNESDAY...MODERATE CONFIDENCE.
IMPROVING. VFR. NW-WINDS POTENTIALLY GUSTY UP TO 20 KTS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE.
THROUGH TONIGHT...5 FT SEAS NE MA COASTAL WATERS WILL SUBSIDE
THIS EVENING. EXPECT WINDS TO DIMINISH AND BECOME LIGHT EASTERLY
WITH SEAS BELOW SCA. AREAS OF DENSE FOG DEVELOPING WILL RESULT IN
POOR VSBYS.
SATURDAY...WINDS TURN SOUTHERLY AND INCREASE DURING THE AFTERNOON
BUT REMAINING BELOW SCA. AREAS OF DENSE FOG IN THE MORNING WITH
IMPROVEMENT IN VSBYS DURING THE AFTERNOON.
SATURDAY NIGHT...MAINLY SW WINDS 15 KT OR LESS WITH SEAS BELOW
SCA. AREAS OF DENSE FOG REDEVELOPING.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY INTO MONDAY...MODERATE CONFIDENCE.
BREEZY S/SW-FLOW BUT REMAINING BELOW SMALL-CRAFT ADVISORY CRITERIA.
GUSTS UP TO 20 KTS WITH THE POSSIBILITY OF WAVES BUILDING UP TO 5-
FEET ON THE OUTER WATERS. LIKELY MARINE STRATUS / FOG AHEAD OF ANA.
LOW VISIBILITIES ON THE WATERS AT TIMES MIXED IN WITH DRIZZLE.
TUESDAY...LOW CONFIDENCE.
APPROACHING COOL FRONT AHEAD OF WHICH ANA LIFTS NE ACROSS 40N/70W.
SCATTERED SHOWERS...LOW CONFIDENCE ON THUNDERSTORMS. INCREASING SW-
WINDS AHEAD OF THE COLD FRONT COULD GUST IN EXCESS OF 25 KTS. ALONG
WITH SWELL FROM ANA...COULD BE LOOKING AT SEAS OF 6-8 FEET ON THE S
AND SE WATERS EXPOSED TO THE ATLANTIC.
WEDNESDAY...MODERATE CONFIDENCE.
CONDITIONS IMPROVING AS ANA MOVES E. SWELL DIMINISHING SLOWLY UNDER
BREEZY NW-WINDS WITH GUSTS UP TO 20 KTS. WAVE HEIGHTS DROPPING BELOW
5-FEET ON THE S/SE-OUTER WATERS BY THURSDAY MORNING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002-003.
MA...DENSE FOG ADVISORY UNTIL 10 AM EDT SATURDAY FOR MAZ023-024.
DENSE FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM EDT
SATURDAY FOR MAZ018>022.
RI...DENSE FOG ADVISORY UNTIL 10 AM EDT SATURDAY FOR RIZ008.
DENSE FOG ADVISORY FROM 10 PM THIS EVENING TO 9 AM EDT
SATURDAY FOR RIZ006-007.
MARINE...NONE.
&&
$$
SYNOPSIS...KJC/SIPPRELL
NEAR TERM...KJC/SIPPRELL
SHORT TERM...KJC
LONG TERM...SIPPRELL
AVIATION...KJC/SIPPRELL
MARINE...KJC/SIPPRELL
AREA FORECAST DISCUSSION
NWS NEW YORK NY
634 PM EDT THU MAY 7 2015
.SYNOPSIS...
HIGH PRESSURE JUST OFFSHORE TO OUR EAST WILL HEAD FARTHER OUT
INTO THE WESTERN ATLANTIC THROUGH THE WEEKEND. LOW PRESSURE WILL
REMAIN NEARLY STATIONARY NEAR THE CAROLINAS THIS
WEEKEND...BRINGING AN INCREASE IN HUMIDITY THROUGH MONDAY. A COLD
FRONT WILL APPROACH ON TUESDAY...AND PASS OFFSHORE ON WEDNESDAY.
HIGH PRESSURE BUILDS ACROSS THE AREA ON WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
HIGH PRESSURE WILL BE CENTERED JUST OFF TO OUR EAST. LATEST
GUIDANCE INCLUDING HRRR AND NARRE INDICATE STRATUS CURRENTLY
OBSERVED OFF THE NJ COAST EXPANDING NORTHWARD AND SPREADING
ACROSS THE LI COAST. DEW POINTS AT THE BUOYS OBSERVED CLOSE TO
WATER TEMPS...BUT STILL MUCH LOWER OVER LAND. WILL NEED TO KEEP
AN EYE ON THIS POSSIBLE EXPANSION NORTHWARD. OTHERWISE...THE
COMBINATION OF CLEAR SKIES AND LIGHT WINDS WITH SOME INCREASE OF
SFC MOISTURE LEVELS SHOULD LEAD TO AT LEAST PATCHY RADIATION FOG
LATE TONIGHT.
TEMPS TONIGHT WILL BE AROUND 5-10 DEGREES WARMER THAN LAST NIGHT IN
MOST LOCATIONS.
&&
.SHORT TERM /FRIDAY NIGHT/...
SUNNY ON FRIDAY WITH AN UPPER RIDGE AXIS SHIFTING IN FROM THE WEST.
SEA BREEZES LIKELY DEVELOP AGAIN AS WINDS THROUGH THE MIXED LAYER
WILL BE LIGHT DURING THE MORNING. MIXING PROFILE LOOKS SIMILAR TO
EARLIER TODAY...BUT TOP OF THE MIXED LAYER SHOULD BE A LITTLE
WARMER. HAVE GONE ABOVE GUIDANCE FOR HIGH TEMPS FOR SEVERAL AREAS
BASED ON THIS. HIGHS IN THE 80S FOR SEVERAL INLAND LOCATIONS AS
WELL AS FOR PARTS OF THE CITY AND NORTHERN PARTS OF LONG ISLAND.
70S JUST ABOUT EVERYWHERE ELSE.
BETTER AGREEMENT AMONG THE MODELS FOR STRATUS AND AREAS OF FOG
MOVING IN FOR FRIDAY NIGHT AS HIGHER DEWPOINTS ADVECT OVER THE
COLDER SEA SURFACE TEMPERATURES. LIFT LOOKS WEAK...SO WILL GO WITH
A DRY FORECAST...BUT PATCHY DRIZZLE COULD OCCUR.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AN UPPER LEVEL RIDGE PERSISTS ACROSS THE EASTERN SEABOARD THIS
WEEKEND WHILE A SURFACE LOW SPINS OFF THE CAROLINA COAST. A SOUTH
TO SOUTHEAST FLOW WILL CONTINUE TO PUSH WARM MOIST AIR ACROSS THE
AREA OVER THE WEEKEND. THIS SHOULD ALLOW FOR SOME EXTENSIVE FOG
AND DRIZZLE. THE FOG WILL BURN OFF EACH DAY ACROSS THE INTERIOR
SECTIONS FIRST..WITH PLACES ALONG THE COAST HOLDING ON TO THE FOG
LONGER AND POSSIBLY NOT BURNING THRU THE FOG AT ALL.
ON MONDAY...WITH SOUTH WINDS INCREASING AND THE WARM MOIST AIR
STILL IN PLACE...WILL CONTINUE TO MENTION A CHANCE OF SHOWERS AND
THUNDERSTORMS. A COLD FRONT IS THEN FORECAST TO CROSS THE AREA ON
TUESDAY WITH MOISTURE FROM THE LOW PRESSURE SYSTEM NEAR THE
CAROLINA COAST INCREASING. THIS MAY RESULT IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND THUNDERSTORMS THAT MAY PRODUCE SOME NEEDED
RAINS ON TUESDAY INTO EARLY WEDNESDAY. DRY AIR MOVES INTO THE AREA
WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
VFR - SKY CLEAR. HIGH PRESSURE OVER THE REGION.
SOME GROUND FOG IS EXPECTED AROUND SUNRISE...THOUGH NOT
ANTICIPATING MUCH IN THE WAY OF IMPACT EVEN IN THE MORE FOG PRONE
SATELLITE TERMINALS.
...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: HIGH CONFIDENCE IN WIND DIRECTION 170-190
MAGNETIC FOR AFTN DEPARTURE BANK. GUSTS NOT EXPECTED.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN WIND FCST.
KEWR FCSTER COMMENTS: HIGH CONFIDENCE THAT WIND DIRECTION STAYS
SOUTH OF 130 MAGNETIC...ESPECIALLY AS THE AFTN PROGRESSES.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
.OUTLOOK FOR 18Z FRI THROUGH TUE...
.FRI AFTN...VFR.
.FRI NGT-TUE...HIGH POTENTIAL FOR LATE NIGHT AND EARLY MORNING
IFR/LIFR CONDS IN FOG AND STRATUS. OTHERWISE VFR.
&&
.MARINE...
NEED TO KEEP ON EYE ON FOG OVERNIGHT AND INTO FRIDAY. WINDS AND
SEAS REMAIN BLW SCA LVLS INTO MON WITH A WEAK SLY FLOW. AS THE
FLOW INCREASES IN ADVANCE OF A COLD FRONT...SEAS INCREASE TO ABOVE
SCA LEVELS TUESDAY AND REMAINING THROUGH THE MIDDLE OF THE WEEK.
SEAS FALL BACK TO BELOW SCA LEVELS ON THURSDAY AS HIGH PRESSURE
BUILDS ACROSS THE AREA WATERS.
&&
.HYDROLOGY...
NO RAIN IS EXPECTED THROUGH THE WEEKEND. SOME ORGANIZED PCPN IS
POSSIBLE TUESDAY INTO WEDNESDAY IN ASSOCIATION WITH A COLD
FRONTAL PASSAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JC/FIG
NEAR TERM...JC/PW
SHORT TERM...JC
LONG TERM...FIG
AVIATION...TONGUE
MARINE...JC/FIG/PW
HYDROLOGY...JC/FIG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
910 PM EDT FRI MAY 8 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND THROUGH
THE WEEKEND. SUB TROPICAL STORM ANA WILL MEANDER OFF THE CAROLINA
COASTAL AREAS THIS WEEKEND AND THEN SLOWLY MOVE NORTH WARD EARLY
NEXT WEEK. A COLD FRONT WILL CROSS OUR AREA TUESDAY. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STRATUS IS COMING IN FIRST ALONG THE NJ COAST WITH VSBYS SO FAR
ABOVE ADVY LEVELS AT AIRPORTS. DELAWARE COASTAL STRIP CONVERSELY
LOOKS VERY FOGGY ON TRAFFIC CAMS. TEMPS AND DEW POINTS ARE
RAPIDLY CONVERGING ALONG THE COAST, SO THE PROCESS IS UNDERWAY.
THERE REMAINS MODEL DIFFERENCES BETWEEN THE NARRE AND HRRR AS
TO VSBY REDUCTIONS. ALSO THE UPS CROSS OVER METHOD IS INDICATING
THE GREATEST FOG POTENTIAL TOWARD NYC WITH STRATUS OVER FOG IN THE
SW PART OF OUR CWA. WITH CONFLICTING INFORMATION AND FOG JUST
ENTERING OUR CWA, WE ARE NOT PLANNING ANY CHANGES TO THE PRESENT
DENSE FOG ADVY. MENTION OF AREAS OR PATCHY FOG BEYOND THE DENSE
FOG ADVY AREA HAS BEEN KEPT. WE MADE SOME TEMP AND DEW POINT
ADJUSTMENTS BASED ON CURRENT TRENDS, OTHERWISE NO OTHER BIG
CHANGES.
A PERSISTENT ONSHORE FLOW PATTERN IS EXPECTED TO CONTINUE FOR
TONIGHT (AND REALLY THROUGH THE WEEKEND). WITH DEW POINTS STILL
HIGHER THAN WATER TEMPS, CURRENT FOG OVER THE OCEAN SHOULD ONCE
AGAIN SPREAD INLAND AND BECOME DENSE AGAIN. THE HRRR WHICH DID
VERY WELL WITH THE DENSE FOG LAST NIGHT WAS HITTING NEW JERSEY
HARD WITH THE FOG AGAIN. IN DELMARVA (TU AKQ AND LWX) THE UPS
CROSSOVER PROCEDURE IS SUGGESTING MORE STRATUS THAN FOG. THE NARRE
THRU 05Z IS MORE SERN NJ AND DE CENTRIC. LAST NIGHT IT WAS A BIT
TOO CONSERVATIVE.
THE DENSE FOG ADVISORY IS CURRENTLY IN EFFECT FOR THE COAST AND
NO CHANGE IN STARTING TIME FOR ALL OF DELAWARE AND PRETTY MUCH
ALONG AND EAST OF THE I295/NJ TURNPIKE CORRIDOR STARTING LATER
TONIGHT. MIN TEMPERATURES ARE A STAT GUIDANCE BLEND.
&&
.SHORT TERM /6 AM SATURDAY THROUGH 6 AM SATURDAY/...
MODEL FORECASTING SOUNDINGS ARE SUGGESTING A SLOWER BURNING OFF THE
FOG AND THE LOW CLOUDS THAN OCCURRED TODAY. EITHER WAY GIVEN THE
LENGTH OF THE DAY, THE SUN WILL GET ITS WAY AND ERODE THE CLOUDS.
MODELS HAVE BEEN FORECASTING SOME ISOLATED CONVECTION. MOST OF
IT IS PREDICATED ON PREDICTED SFC DEW POINTS THAT ARE 5-10F HIGHER
THAN THEIR OWN STAT GUIDANCE. A MORE REALISTIC MIXING OF SUB 850MB
MOISTURE WOULD HAVE THE CAP HOLD IN MOST OF OUR CWA. THE ONLY
LOCATION WHERE STAT AND SFC PREDICTED DEW POINTS COME CLOSE IS IN
DELMARVA. MESOSCALE MODELS ARE ALSO SHOWING A DOUBLE BAY BREEZE
CONVERGENCE AND WE KEPT AN ISOLATED CHANCE OF AFTERNOON THUNDER
THERE.
HIGHER GFS MOS STAT GUIDANCE LOOKS BETTER. BOTH NAM AND GFS FCST MAX
TEMPS OFF THEIR AFTN SOUNDINGS ARE MORE IN LINE WITH GFS MOS. THE
LATTER IS ALREADY TOO LOW IN NORTHWEST AREAS TODAY.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
SAT NIGHT THRU SUN NIGHT...THE WEAK RIDGE OF HIGH PRESSURE WILL
REMAIN ACROSS THE AREA. LITTLE IN THE WAY OF MEASURABLE RAINS ARE
EXPECTED...BUT SCT TSTMS ARE POSSIBLE SUN AFTERNOON. AREAS OF FOG
AND DRIZZLE ARE EXPECTED SAT NIGHT AND SUN NIGHT. TEMPERATURES WILL
REMAIN ABOVE NORMAL FOR EARLY MAY.
MON THRU TUE NIGHT...AN UNSETTLED PERIOD WITH THE MOISTURE FROM ANA
AND AN APPROACHING COLD FRONT ACTING UPON THE INCREASED LOW LEVEL
MOISTURE. SCT SHOWERS AND TSTMS FAVORING THE AFTERNOON AND EARLY
EVENING HOURS. SOME LOCALLY HEAVY RAINS ARE POSSIBLE. TEMPERATURES
STILL ABOVE NORMAL WITH HUMID CONDITIONS EXPECTED.
WED THRU FRI...FAIR WEATHER WILL RETURN BEHIND THE COLD FRONT WED.
THE FAIR WEATHER WILL CONTINUE INTO FRI. TEMPERATURES WILL DROP
BACK TO NORMAL LEVELS WED AND REMAIN NEAR NORMAL THRU FRI. THE
AIR WILL BE DRIER/MORE COMFORTABLE THAN MON/TUE.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
00Z TAFS BRING ALL SITES TO IFR TOWARD MORNING, COASTAL AIRPORTS
FIRST. AIR MASS IS DRIER THAN AT THIS POINT LAST NIGHT, SO FOG
AND STRATUS FORMATION IS SLOWER THAN PREVIOUS TAFS AND LAST
NIGHT. LIKE LAST NIGHT THE UNCERTAINTY OF LIFR CONDITIONS REACHING
INLAND ON SATURDAY MORNING IS AROUND THE KPHL CORRIDOR AIRPORTS.
THIS EVENING...VFR ALL TAF SITES WITH NO CIGS. GREATEST
UNCERTAINTY RANG TRUE AT KACY AS STRATUS CAME FLYING IN AT SUNSET.
LIGHT SOUTH WINDS.
OVERNIGHT...IFR FOG AND STRATUS CIG PREDICTED TO MOVE INLAND.
TIMING IS APPROXIMATELY TWO TO THREE HOURS LATER THAN LAST NIGHT.
AWAY FROM KACY AND KMIV THERE IS SOME UNCERTAINTY AS TO WHICH
FORMS FIRST, THE STRATUS OR THE FOG. WHILE IFR CONDITIONS
EXPECTED, THE FORMATION OF THE CIG FIRST WOULD PREVENT LIFR VSBYS
FROM OCCURRING. LIGHT EAST WINDS.
SATURDAY MORNING...IMPROVING CONDITIONS. EXPECTATION IS FOR
SLOWEST IMPROVEMENT FROM LIFR AT THE COASTAL AIRPORTS AND
TERMINALS, BUT THE SLOWEST IMPROVEMENT FROM MVFR TO VFR TO
OCCUR AT NORTHWEST AND NORTH AIRPORTS AND TERMINALS. (MAYBE NOT
TIL EARLY AFTERNOON). SOUTHEAST WINDS 5 TO 10 KNOTS.
SATURDAY AFTERNOON...VFR CIGS AT INLAND TERMINALS AND JUST A
SCATTERED CU DECK AT COASTAL AIRPORTS. NO APPARENT SEA BREEZE
PREDICTED, JUST A GENERAL SOUTH TO SOUTHEAST WIND CLOSE TO 10
KNOTS.
OUTLOOK...
SAT NIGHT THRU SUN NIGHT...LOCALLY POOR CONDITIONS IN
FOG/DRIZZLE/LOW CLOUDS. SCT SHOWERS SUN AFTERNOON.
MON THRU TUE NIGHT...SCT SHOWERS/TSTMS WITH LOWER CONDITIONS
POSSIBLE. AREAS OF FOG NEAR THE COAST.
WED...MOSTLY VFR.
&&
.MARINE...
WE HAVE EXTENDED THE DENSE FOG ADVISORY FOR MOST OF THE AREA
WATERS THROUGH NOON ON SATURDAY, FROM MANASQUAN INLET, NJ SOUTH TO
FENWICK ISLAND, DE AND FOR SOUTHERN DELAWARE BAY. DENSE FOG IS
EXPECTED TO CONTINUE FOR THESE AREAS THROUGH MIDDAY SATURDAY BASED
ON LATEST OBSERVATIONS FROM MARINERS AND SATELLITE IMAGERY.
ELSEWHERE, FOR THE WATERS OFF THE MONMOUTH COUNTY COAST AND FOR
THE UPPER DELAWARE BAY, VISIBILITY CONDITIONS HAVE BRIEFLY
IMPROVED THIS AFTERNOON BUT ARE ANTICIPATED TO ONCE AGAIN
DETERIORATE THIS EVENING AND TONIGHT. THE DENSE FOG ADVISORY GOES
INTO EFFECT FOR THESE AREAS FROM 7PM THIS EVENING THROUGH NOON
SATURDAY.
OTHERWISE, WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA THROUGH TONIGHT.
OUTLOOK...
SAT NIGHT THRU SUN NIGHT...SUB-SCA CONDITIONS. AREAS OF DRIZZLE
AND FOG.
MON THRU TUE...LOW-END SCA CONDITIONS FOR SEAS POSSIBLE. SCT
TSTMS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...DENSE FOG ADVISORY UNTIL 11 AM EDT SATURDAY FOR NJZ014-024>026.
DENSE FOG ADVISORY UNTIL 9 AM EDT SATURDAY FOR NJZ013-016>023-
027.
DE...DENSE FOG ADVISORY UNTIL 11 AM EDT SATURDAY FOR DEZ004.
DENSE FOG ADVISORY UNTIL 9 AM EDT SATURDAY FOR DEZ001>003.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...KLINE/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
725 PM EDT FRI MAY 8 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND THROUGH
THE WEEKEND. SUB TROPICAL STORM ANA WILL MEANDER OFF THE CAROLINA
COASTAL AREAS THIS WEEKEND AND THEN SLOWLY MOVE NORTH WARD EARLY
NEXT WEEK. A COLD FRONT WILL CROSS OUR AREA TUESDAY. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SHORT TERM UPDATE MAINLY FOR TEMPERATURES. DEW POINTS HAVE DROPPED
AND VSBYS HAVE IMPROVED ALONG THE COAST. WHILE THE NARRE AND HRRR
STILL FOG IN OUR CWA OVERNIGHT, IT LOOKS TO BE DELAYED BY A COUPLE
OF HOURS VS LAST NIGHT.
A PERSISTENT ONSHORE FLOW PATTERN IS EXPECTED TO CONTINUE FOR
TONIGHT (AND REALLY THROUGH THE WEEKEND). WITH DEW POINTS STILL
HIGHER THAN WATER TEMPS, CURRENT FOG OVER THE OCEAN SHOULD ONCE
AGAIN SPREAD INLAND AND BECOME DENSE AGAIN. THE HRRR WHICH DID
VERY WELL WITH THE DENSE FOG LAST NIGHT WAS HITTING NEW JERSEY
HARD WITH THE FOG AGAIN. IN DELMARVA (TU AKQ AND LWX) THE UPS
CROSSOVER PROCEDURE IS SUGGESTING MORE STRATUS THAN FOG. THE NARRE
THRU 05Z IS MORE SERN NJ AND DE CENTRIC. LAST NIGHT IT WAS A BIT
TOO CONSERVATIVE.
AS A FIRST STEP, WE ARE GOING TO ISSUE A DENSE FOG ADVISORY STARTING
NEARLY IMMEDIATELY FOR THE COAST AND THEN INCLUDING ALL OF DELAWARE
AND PRETTY MUCH EAST OF THE I295/NJ TURNPIKE CORRIDOR STARTING LATER
TONIGHT. WE WILL CARRY PATCHIER FOG FOR LOCATIONS FARTHER TO THE
NORTHWEST AND WEST AND LET THE EVENING SHIFT REASSESS. MIN
TEMPERATURES ARE A STAT GUIDANCE BLEND.
&&
.SHORT TERM /6 AM SATURDAY THROUGH 6 AM SATURDAY/...
MODEL FORECASTING SOUNDINGS ARE SUGGESTING A SLOWER BURNING OFF THE
FOG AND THE LOW CLOUDS THAN OCCURRED TODAY. EITHER WAY GIVEN THE
LENGTH OF THE DAY, THE SUN WILL GET ITS WAY AND ERODE THE CLOUDS.
MODELS HAVE BEEN FORECASTING SOME ISOLATED CONVECTION. MOST OF
IT IS PREDICATED ON PREDICTED SFC DEW POINTS THAT ARE 5-10F HIGHER
THAN THEIR OWN STAT GUIDANCE. A MORE REALISTIC MIXING OF SUB 850MB
MOISTURE WOULD HAVE THE CAP HOLD IN MOST OF OUR CWA. THE ONLY
LOCATION WHERE STAT AND SFC PREDICTED DEW POINTS COME CLOSE IS IN
DELMARVA. MESOSCALE MODELS ARE ALSO SHOWING A DOUBLE BAY BREEZE
CONVERGENCE AND WE KEPT AN ISOLATED CHANCE OF AFTERNOON THUNDER
THERE.
HIGHER GFS MOS STAT GUIDANCE LOOKS BETTER. BOTH NAM AND GFS FCST MAX
TEMPS OFF THEIR AFTN SOUNDINGS ARE MORE IN LINE WITH GFS MOS. THE
LATTER IS ALREADY TOO LOW IN NORTHWEST AREAS TODAY.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
SAT NIGHT THRU SUN NIGHT...THE WEAK RIDGE OF HIGH PRESSURE WILL
REMAIN ACROSS THE AREA. LITTLE IN THE WAY OF MEASURABLE RAINS ARE
EXPECTED...BUT SCT TSTMS ARE POSSIBLE SUN AFTERNOON. AREAS OF FOG
AND DRIZZLE ARE EXPECTED SAT NIGHT AND SUN NIGHT. TEMPERATURES WILL
REMAIN ABOVE NORMAL FOR EARLY MAY.
MON THRU TUE NIGHT...AN UNSETTLED PERIOD WITH THE MOISTURE FROM ANA
AND AN APPROACHING COLD FRONT ACTING UPON THE INCREASED LOW LEVEL
MOISTURE. SCT SHOWERS AND TSTMS FAVORING THE AFTERNOON AND EARLY
EVENING HOURS. SOME LOCALLY HEAVY RAINS ARE POSSIBLE. TEMPERATURES
STILL ABOVE NORMAL WITH HUMID CONDITIONS EXPECTED.
WED THRU FRI...FAIR WEATHER WILL RETURN BEHIND THE COLD FRONT WED.
THE FAIR WEATHER WILL CONTINUE INTO FRI. TEMPERATURES WILL DROP
BACK TO NORMAL LEVELS WED AND REMAIN NEAR NORMAL THRU FRI. THE
AIR WILL BE DRIER/MORE COMFORTABLE THAN MON/TUE.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY, AND SURROUNDING AREAS.
00Z TAFS BRING ALL SITES TO IFR TOWARD MORNING, COASTAL AIRPORTS
FIRST. AIR MASS IS DRIER THAN AT THIS POINT LAST NIGHT, SO FOG
AND STRATUS FORMATION IS SLOWER THAN PREVIOUS TAFS AND LAST
NIGHT. LIKE LAST NIGHT THE UNCERTAINTY OF LIFR CONDITIONS REACHING
INLAND ON SATURDAY MORNING IS AROUND THE KPHL CORRIDOR AIRPORTS.
THIS EVENING...VFR ALL TAF SITES WITH NO CIGS. GREATEST
UNCERTAINTY AT KACY BECAUSE OF FOG TIMING, HAVE CONDITIONS
STARTING TO LOWER THERE AT MIDNIGHT. LIGHT SOUTH WINDS.
OVERNIGHT...IFR FOG AND STRATUS CIG PREDICTED TO MOVE INLAND.
TIMING IS APPROXIMATELY TWO TO THREE HOURS LATER THAN LAST NIGHT.
AWAY FROM KACY AND KMIV THERE IS SOME UNCERTAINTY AS TO WHICH
FORMS FIRST, THE STRATUS OR THE FOG. WHILE IFR CONDITIONS
EXPECTED, THE FORMATION OF THE CIG FIRST WOULD PREVENT LIFR VSBYS
FROM OCCURRING. LIGHT EAST WINDS.
SATURDAY MORNING...IMPROVING CONDITIONS. EXPECTATION IS FOR
SLOWEST IMPROVEMENT FROM LIFR AT THE COASTAL AIRPORTS AND
TERMINALS, BUT THE SLOWEST IMPROVEMENT FROM MVFR TO VFR TO
OCCUR AT NORTHWEST AND NORTH AIRPORTS AND TERMINALS. (MAYBE NOT
TIL EARLY AFTERNOON). SOUTHEAST WINDS 5 TO 10 KNOTS.
SATURDAY AFTERNOON...VFR CIGS AT INLAND TERMINALS AND JUST A
SCATTERED CU DECK AT COASTAL AIRPORTS. NO APPARENT SEA BREEZE
PREDICTED, JUST A GENERAL SOUTH TO SOUTHEAST WIND CLOSE TO 10
KNOTS.
OUTLOOK...
SAT NIGHT THRU SUN NIGHT...LOCALLY POOR CONDITIONS IN
FOG/DRIZZLE/LOW CLOUDS. SCT SHOWERS SUN AFTERNOON.
MON THRU TUE NIGHT...SCT SHOWERS/TSTMS WITH LOWER CONDITIONS
POSSIBLE. AREAS OF FOG NEAR THE COAST.
WED...MOSTLY VFR.
&&
.MARINE...
WE ARE STILL EXPECTING DENSE FOG TO FORM TONIGHT.
WE HAVE EXTENDED THE DENSE FOG ADVISORY FOR MOST OF THE AREA
WATERS THROUGH NOON ON SATURDAY, FROM MANASQUAN INLET, NJ SOUTH
TO FENWICK ISLAND, DE AND FOR SOUTHERN DELAWARE BAY. DENSE FOG IS
EXPECTED TO CONTINUE FOR THESE AREAS THROUGH MIDDAY SATURDAY BASED
ON LATEST OBSERVATIONS FROM MARINERS AND SATELLITE IMAGERY.
ELSEWHERE, FOR THE WATERS OFF THE MONMOUTH COUNTY COAST AND FOR
THE UPPER DELAWARE BAY, VISIBILITY CONDITIONS HAVE BRIEFLY
IMPROVED THIS AFTERNOON BUT ARE ANTICIPATED TO ONCE AGAIN
DETERIORATE THIS EVENING AND TONIGHT. THE DENSE FOG ADVISORY GOES
INTO EFFECT FOR THESE AREAS FROM 7PM THIS EVENING THROUGH NOON
SATURDAY.
OTHERWISE, WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA THROUGH TONIGHT.
OUTLOOK...
SAT NIGHT THRU SUN NIGHT...SUB-SCA CONDITIONS. AREAS OF DRIZZLE
AND FOG.
MON THRU TUE...LOW-END SCA CONDITIONS FOR SEAS POSSIBLE. SCT
TSTMS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...DENSE FOG ADVISORY UNTIL 11 AM EDT SATURDAY FOR NJZ014-024>026.
DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY
FOR NJZ013-016>023-027.
DE...DENSE FOG ADVISORY UNTIL 11 AM EDT SATURDAY FOR DEZ004.
DENSE FOG ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EDT SATURDAY
FOR DEZ001>003.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL NOON EDT SATURDAY FOR ANZ430-431-
450>455.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/O`HARA
MARINE...KLINE/MEOLA/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
621 PM EDT THU MAY 7 2015
.SYNOPSIS...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION TONIGHT
WITH A SECONDARY AREA OF HIGH PRESSURE BUILDING ACROSS THE MID
ATLANTIC STATES ON FRIDAY. THIS FEATURE WILL BE IN PLACE THROUGH THE
WEEKEND WITH AN AREA OF LOW PRESSURE OFF THE CAROLINA COASTLINE. FOR
THE EARLY PART OF NEXT WEEK, A COLD FRONT WITH AN ASSOCIATED AREA
OF LOW PRESSURE WILL MOVE ACROSS THE CENTRAL AND EASTERN UNITED
STATES AS THE LOW OFF THE CAROLINA COASTLINE WEAKENS. HIGH
PRESSURE WILL BUILD IN BEHIND THE COLD FRONT FOR THE MIDDLE PART
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WITH AN INTERMEDIATE UPDATE WE WERE MORE AGGRESSIVE WITH THE
ADVECTION OF FOG ONTO LAND AREAS FOR TONIGHT. LATEST HRRR
AND NARRE EMPHASIZING DELMARVA AND SERN NJ AS MOST FOG PRONE.
THERE IS ALREADY SOME PATCHY DENSE FOG FROM ACY SOUTHWARD. THERE
ARE DIFFERENCES IN THE NARRE VS THE HRRR AS TO THE EXTENT OF THE
DENSE FOG. THE FORMER IS RESTRICTED MORE TO JUST COASTAL SUSSEX
WHILE THE LATTER WRAPS UP THE DELAWARE NEARLY TO PHILLY.
CONFIDENCE ABOUT THE FOG IS NOT HIGH, BUT WE WILL FOLLOW TRENDS
AND SEE HOW QUICK THE SUNSET ADVECTION IS AND LIKELY MAKE A
DECISION WITH THE NEXT PLANNED UPDATE.
REST OF THE CWA REMAINS QUIET AND JUST SOME CURRENT TEMP AND DEW
POINTS ADJUSTMENTS WERE MADE THERE.
FAIR WEATHER TO CONTINUE OVERNIGHT WITH HIGH PRESSURE MOVING
OFFSHORE. PATCHY FOG OVERNIGHT MOST AREAS...PERHAPS NOT AS MUCH
FAR NORTH. MORE WIDESPREAD AREAS OF FOG ALONG THE SRN NJ/DELMARVA.
LOWS OVERNIGHT WILL DROP INTO THE MID/UPPER 50S MOST AREAS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FAIR WEATHER WILL CONTINUE FRIDAY. THERE WILL STILL BE SOME FOG
AROUND EARLY...BUT THE SUN WILL QUICKLY BURN THINGS OFF BY AROUND 8
AM OR SO. ITS POSSIBLE THAT SOME FOG MAY LINGER ACROSS THE
COAST...LIKE TODAY. HIGH TEMPS FRI WILL RISE INT THE UPPER 70S/LOW
80S MOST AREAS...COOLER NEAR THE SHORE. WINDS SHOULD MOSTLY S OR SW
AT 5 TO 10 MPH DURING THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
GOOD AGREEMENT WITH THE VARIOUS ENSEMBLE AND OPERATIONAL MODELS
WITH THE GENERAL OVERALL PATTERN IN ALL PERIODS. THE MAIN
DISCREPANCY IS THE ECMWF AND THE ECMWF NUMERICAL GUIDANCE LOOK TO
COOL IN THE THREE TO FIVE DAY, WHILE THE GFS IS PERHAPS A TAD TO
WARM. ANY TROPICAL DEVELOPMENT OF THE LOW PRESSURE SYSTEM OFF THE
CAROLINAS MAY LEAD TO HIGHER RAIN CHANCES EARLY NEXT WEEK WITH ANY
OTHER IMPACTS TO DAILY WEATHER VERY LIMITED. DETAILS BELOW...
THIS WEEKEND: WITH HIGH PRESSURE LOCATED TO OUR NORTHEAST AND A LOW
PRESSURE OFF THE CAROLINA COAST A SOUTHEASTERLY FLOW WILL BE IN
PLACE. MOISTURE WILL BE ON THE INCREASE EACH DAY ALONG WITH RISING
925 MB TEMPERATURES AS A WARMER AIRMASS IS ADVECTED INTO THE REGION.
MANY LOCATIONS ARE LIKELY TO GET INTO THE LOW/MID 80`S ON AVERAGE
AFTER STARTING OUT IN THE UPPER 50`S/LOW 60`S. THE SOUTHEAST FLOW IS
LIKELY TO KEEP TEMPERATURES ALONG THE COAST COOLER. WITH THE LIGHT
SOUTHEASTERLY FLOW SOME MORNING FOG EACH DAY COULD OCCUR. ALSO THE
INCREASED INSTABILITY AND HUMIDITY MAY LEAD TO AN ISOLATED SHOWER OR
STORM. NO TRIGGER IN THIS PERIOD FOR ANYTHING MORE THAN ISOLATED TO
PERHAPS SCATTERED SHOWERS AND STORMS, GOING SLIGHT CHANCE ATTM.
MONDAY AND TUESDAY: A COLD FRONT WILL MOVE INTO THE REGION BY
TUESDAY ALONG WITH MOISTURE INCREASING FROM A DECAYING LOW PRESSURE
SYSTEM NEAR OR NORTH OF THE CAROLINAS. THESE TWO FEATURES WILL
RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
THAT MAY PRODUCE SOME NEEDED RAINS. ENOUGH SEPARATION WITH THESE
FEATURES WILL LIMIT THE WIDESPREAD HEAVY RAIN THREAT BUT SOME
LOCALIZED DOWNPOURS ARE POSSIBLE. LOW LEVEL MOISTURE AND LIGHT
WINDS MAY RESULT IN ADDITIONAL PERIODS OF PATCHY FOG. RISING 925 MB
TEMPERATURES TO AROUND 20C SHOULD ALLOW INLAND AREAS TO RUN WELL
ABOVE CURRENT NUMERICAL GUIDANCE AND MODELED TWO METER TEMPERATURES
IN THE MID 80`S WITH OVERNIGHT LOWS EACH MORNING IN THE LOW TO MID
60`S. IN TERMS OF ANY SEVERE THREAT WITH THE FRONT, THIS LOOKS
LIMITED AS THE BEST DYNAMICS WILL BE NORTHWEST OF THE MORE
FAVORABLE INSTABILITY ATTM. AREAS THAT DO NOT SEE THE SCATTERED
STORMS WILL SLIP CLOSER TO DROUGHT CONDITIONS AS SHORT TERM DEFICITS
WITH RAINFALL CONTINUE TO GROW.
WEDNESDAY AND THURSDAY: AFTER THE COLD FRONTAL PASSAGE, HIGH
PRESSURE WILL BUILD INTO THE REGION WITH A DRIER AND COOLER AIRMASS.
GOING WITH A LARGER TEMPERATURE SPREAD THAN THE MODELED TWO METER
VALUES. CONSIDERABLE SUNSHINE MAY STILL ALLOW FOR HIGHS INTO THE
70`S AFTER CHILLIER STARTS IN THE 40`S/50`S. THE MAIN CONCERN MAY
END UP BEING FAVORABLE CONDITIONS FOR FIRE SPREAD. RH VALUES AROUND
35% EACH AFTERNOON COUPLED WITH STRONG WEST-NORTHWEST WINDS ARE
POSSIBLE.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
BASICALLY A FAIR WEATHER PATTERN ACROSS THE REGION TONIGHT AND
FRIDAY. HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT AND LITTLE
CLOUDINESS OR WIND IS EXPECTED. THERE IS THE POSSIBILITY FOR FOG
OVERNIGHT WITH THE LOW LEVEL MOISTURE SLOWLY INCREASING ACROSS THE
AREA. WE HAVE KEPT THE FOG FROM THE EARLIER TAFS...AND ADDED A FEW
AREAS SINCE CONDITIONS LOOK RATHER FAVORABLE. THE FOG WILL LIKELY
BURN OFF IN THE 12Z-13Z FRAME FRI WITH VFR AFTER THAT.
OUTLOOK...
FRIDAY NIGHT THROUGH SUNDAY: VFR WITH SOUTH-SOUTHEAST WINDS UNDER 10
KNOTS. SOME MORNING PATCHY LOW FOG POSSIBLE, BEST CHANCES AT RDG,
ACY AND MIV.
MONDAY AND TUESDAY: VFR THROUGHOUT MOST OF THIS PERIOD. SOME
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND
EARLY EVENING EACH DAY LEADING TO MVFR OR LOWER CONDITIONS. SOUTHEAST
WIND GUSTS UNDER 15 KNOTS ON MONDAY AND THEN SOUTHWEST WIND GUSTS
AROUND OR UNDER 20 KNOTS ON TUESDAY. PATCHY FOG POSSIBLE MONDAY
MORNING BEFORE 12Z.
&&
.MARINE...
AFTER COORDINATING WITH THE DAY SHIFT, WE HAVE DECIDED TO ISSUE A
DENSE FOG ADVISORY FOR OUR AREA WATERS THROUGH FRIDAY MORNING.
SOME OF THE TRAFFIC CAMS ALONG THE IMMEDIATE COAST LOOKED VERY
FOGGY. LATEST SREF/NARRE AND HRRR GUIDANCE ARE INDICATING THAT THE
FOG SHOULD CONTINUE AND SPREAD THROUGH THE NIGHT. NOT A CONFIDENT
FORECAST OFF OF MONMOUTH AND IN UPPER DELAWARE BAY AND TIMING
MIGHT HAVE TO BE EXTENDED ON FRIDAY AS FLOW REMAINS WEAK AND DEW
POINTS ABOVE WATER TEMPS.
SUB SCA CONDITIONS WITH FAIR WEATHER TONIGHT AND FRIDAY. THERE IS
SOME FOG ACROSS SE NJ/DEL COASTAL AREAS AND INTO SRN DEL BAY AND
EVEN INTO THE AFTERNOON...IT CONTINUES . IT WILL PROBABLY REMAIN INTO
THE EVENING AND PERHAPS BECOME A BIT MORE CONCENTRATED OVERNIGHT. VERY
LIGHT ONSHORE OR UP THE BAY FLOW INTO EARLY TONIGHT THEN
LIGHT/VARIABLE OVERNIGHT.
OUTLOOK...
SEAS AND WINDS ARE LIKELY TO REMAIN BELOW SCA CRITERIA THROUGH MONDAY
WITH SEAS NEAR FIVE FEET MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES. WINDS WILL BE MAINLY FROM THE SOUTH AND SOUTHEAST THROUGH
MONDAY THEN FROM THE SOUTHWEST UNDER 15 KNOTS WITH GUSTS UNDER 20
KNOTS, HIGHEST ON TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ431-451>455.
DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ430-450.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...O`HARA
SHORT TERM...GIGI/O`HARA
LONG TERM...GAINES
AVIATION...GAINES/O`HARA
MARINE...GAINES/GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
428 PM EDT THU MAY 7 2015
.SYNOPSIS...
HIGH PRESSURE WILL BE IN PLACE ACROSS THE REGION TONIGHT
WITH A SECONDARY AREA OF HIGH PRESSURE BUILDING ACROSS THE MID
ATLANTIC STATES ON FRIDAY. THIS FEATURE WILL BE IN PLACE THROUGH THE
WEEKEND WITH AN AREA OF LOW PRESSURE OFF THE CAROLINA COASTLINE. FOR
THE EARLY PART OF NEXT WEEK, A COLD FRONT WITH AN ASSOCIATED AREA
OF LOW PRESSURE WILL MOVE ACROSS THE CENTRAL AND EASTERN UNITED
STATES AS THE LOW OFF THE CAROLINA COASTLINE WEAKENS. HIGH
PRESSURE WILL BUILD IN BEHIND THE COLD FRONT FOR THE MIDDLE PART
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
NICE WEATHER ACROSS MUCH OF THE AREA TODAY. THERE CONTINUES TO BE
AREAS OF FOG ALONG THE SRN HALF OF NJ`S SHORE AREAS AND ACROSS SRN
DEL BAY AND DE COASTAL AREAS. BRIGHT SUNSHINE AND LIGHT WINDS
ELSEWHERE. TEMPERATURES IN THE UPPER 70S/LOW 80S INLAND AND LOW/MID
70S CLOSER TO THE SHORE...BUT IN THE 60S NEAR THE IMMEDIATE COAST.
FAIR WEATHER TO CONTINUE OVERNIGHT WITH HIGH PRESSURE MOVING
OFFSHORE. PATCHY FOG OVERNIGHT MOST AREAS...PERHAPS NOT AS MUCH FAR
NORTH. MORE WIDESPREAD AREAS OF FOG ALONG THE SRN NJ/DELMARVA. LOWS
OVERNIGHT WILL DROP INTO THE MID/UPPER 50S MOST AREAS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
FAIR WEATHER WILL CONTINUE FRIDAY. THERE WILL STILL BE SOME FOG
AROUND EARLY...BUT THE SUN WILL QUICKLY BURN THINGS OFF BY AROUND 8
AM OR SO. ITS POSSIBLE THAT SOME FOG MAY LINGER ACROSS THE
COAST...LIKE TODAY. HIGH TEMPS FRI WILL RISE INT THE UPPER 70S/LOW
80S MOST AREAS...COOLER NEAR THE SHORE. WINDS SHOULD MOSTLY S OR SW
AT 5 TO 10 MPH DURING THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
GOOD AGREEMENT WITH THE VARIOUS ENSEMBLE AND OPERATIONAL MODELS
WITH THE GENERAL OVERALL PATTERN IN ALL PERIODS. THE MAIN
DISCREPANCY IS THE ECMWF AND THE ECMWF NUMERICAL GUIDANCE LOOK TO
COOL IN THE THREE TO FIVE DAY, WHILE THE GFS IS PERHAPS A TAD TO
WARM. ANY TROPICAL DEVELOPMENT OF THE LOW PRESSURE SYSTEM OFF THE
CAROLINAS MAY LEAD TO HIGHER RAIN CHANCES EARLY NEXT WEEK WITH ANY
OTHER IMPACTS TO DAILY WEATHER VERY LIMITED. DETAILS BELOW...
THIS WEEKEND: WITH HIGH PRESSURE LOCATED TO OUR NORTHEAST AND A LOW
PRESSURE OFF THE CAROLINA COAST A SOUTHEASTERLY FLOW WILL BE IN
PLACE. MOISTURE WILL BE ON THE INCREASE EACH DAY ALONG WITH RISING
925 MB TEMPERATURES AS A WARMER AIRMASS IS ADVECTED INTO THE REGION.
MANY LOCATIONS ARE LIKELY TO GET INTO THE LOW/MID 80`S ON AVERAGE
AFTER STARTING OUT IN THE UPPER 50`S/LOW 60`S. THE SOUTHEAST FLOW IS
LIKELY TO KEEP TEMPERATURES ALONG THE COAST COOLER. WITH THE LIGHT
SOUTHEASTERLY FLOW SOME MORNING FOG EACH DAY COULD OCCUR. ALSO THE
INCREASED INSTABILITY AND HUMIDITY MAY LEAD TO AN ISOLATED SHOWER OR
STORM. NO TRIGGER IN THIS PERIOD FOR ANYTHING MORE THAN ISOLATED TO
PERHAPS SCATTERED SHOWERS AND STORMS, GOING SLIGHT CHANCE ATTM.
MONDAY AND TUESDAY: A COLD FRONT WILL MOVE INTO THE REGION BY
TUESDAY ALONG WITH MOISTURE INCREASING FROM A DECAYING LOW PRESSURE
SYSTEM NEAR OR NORTH OF THE CAROLINAS. THESE TWO FEATURES WILL
RESULT IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
THAT MAY PRODUCE SOME NEEDED RAINS. ENOUGH SEPARATION WITH THESE
FEATURES WILL LIMIT THE WIDESPREAD HEAVY RAIN THREAT BUT SOME
LOCALIZED DOWNPOURS ARE POSSIBLE. LOW LEVEL MOISTURE AND LIGHT
WINDS MAY RESULT IN ADDITIONAL PERIODS OF PATCHY FOG. RISING 925 MB
TEMPERATURES TO AROUND 20C SHOULD ALLOW INLAND AREAS TO RUN WELL
ABOVE CURRENT NUMERICAL GUIDANCE AND MODELED TWO METER TEMPERATURES
IN THE MID 80`S WITH OVERNIGHT LOWS EACH MORNING IN THE LOW TO MID
60`S. IN TERMS OF ANY SEVERE THREAT WITH THE FRONT, THIS LOOKS
LIMITED AS THE BEST DYNAMICS WILL BE NORTHWEST OF THE MORE
FAVORABLE INSTABILITY ATTM. AREAS THAT DO NOT SEE THE SCATTERED
STORMS WILL SLIP CLOSER TO DROUGHT CONDITIONS AS SHORT TERM DEFICITS
WITH RAINFALL CONTINUE TO GROW.
WEDNESDAY AND THURSDAY: AFTER THE COLD FRONTAL PASSAGE, HIGH
PRESSURE WILL BUILD INTO THE REGION WITH A DRIER AND COOLER AIRMASS.
GOING WITH A LARGER TEMPERATURE SPREAD THAN THE MODELED TWO METER
VALUES. CONSIDERABLE SUNSHINE MAY STILL ALLOW FOR HIGHS INTO THE
70`S AFTER CHILLIER STARTS IN THE 40`S/50`S. THE MAIN CONCERN MAY
END UP BEING FAVORABLE CONDITIONS FOR FIRE SPREAD. RH VALUES AROUND
35% EACH AFTERNOON COUPLED WITH STRONG WEST-NORTHWEST WINDS ARE
POSSIBLE.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
BASICALLY A FAIR WEATHER PATTERN ACROSS THE REGION TONIGHT AND
FRIDAY. HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT AND LITTLE
CLOUDINESS OR WIND IS EXPECTED. THERE IS THE POSSIBILITY FOR FOG
OVERNIGHT WITH THE LOW LEVEL MOISTURE SLOWLY INCREASING ACROSS THE
AREA. WE HAVE KEPT THE FOG FROM THE EARLIER TAFS...AND ADDED A FEW
AREAS SINCE CONDITIONS LOOK RATHER FAVORABLE. THE FOG WILL LIKELY
BURN OFF IN THE 12Z-13Z FRAME FRI WITH VFR AFTER THAT.
OUTLOOK...
FRIDAY NIGHT THROUGH SUNDAY: VFR WITH SOUTH-SOUTHEAST WINDS UNDER 10
KNOTS. SOME MORNING PATCHY LOW FOG POSSIBLE, BEST CHANCES AT RDG,
ACY AND MIV.
MONDAY AND TUESDAY: VFR THROUGHOUT MOST OF THIS PERIOD. SOME
SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND
EARLY EVENING EACH DAY LEADING TO MVFR OR LOWER CONDITIONS. SOUTHEAST
WIND GUSTS UNDER 15 KNOTS ON MONDAY AND THEN SOUTHWEST WIND GUSTS
AROUND OR UNDER 20 KNOTS ON TUESDAY. PATCHY FOG POSSIBLE MONDAY
MORNING BEFORE 12Z.
&&
.MARINE...
AFTER COORDINATING WITH THE DAY SHIFT, WE HAVE DECIDED TO ISSUE A
DENSE FOG ADVISORY FOR OUR AREA WATERS THROUGH FRIDAY MORNING.
SOME OF THE TRAFFIC CAMS ALONG THE IMMEDIATE COAST LOOKED VERY
FOGGY. LATEST SREF/NARRE AND HRRR GUIDANCE ARE INDICATING THAT THE
FOG SHOULD CONTINUE AND SPREAD THROUGH THE NIGHT. NOT A CONFIDENT
FORECAST OFF OF MONMOUTH AND IN UPPER DELAWARE BAY AND TIMING
MIGHT HAVE TO BE EXTENDED ON FRIDAY AS FLOW REMAINS WEAK AND DEW
POINTS ABOVE WATER TEMPS.
SUB SCA CONDITIONS WITH FAIR WEATHER TONIGHT AND FRIDAY. THERE IS
SOME FOG ACROSS SE NJ/DEL COASTAL AREAS AND INTO SRN DEL BAY AND
EVEN INTO THE AFTERNOON...IT CONTINUES . IT WILL PROBABLY REMAIN INTO
THE EVENING AND PERHAPS BECOME A BIT MORE CONCENTRATED OVERNIGHT. VERY
LIGHT ONSHORE OR UP THE BAY FLOW INTO EARLY TONIGHT THEN
LIGHT/VARIABLE OVERNIGHT.
OUTLOOK...
SEAS AND WINDS ARE LIKELY TO REMAIN BELOW SCA CRITERIA THROUGH MONDAY
WITH SEAS NEAR FIVE FEET MONDAY NIGHT AND TUESDAY AS A COLD FRONT
APPROACHES. WINDS WILL BE MAINLY FROM THE SOUTH AND SOUTHEAST THROUGH
MONDAY THEN FROM THE SOUTHWEST UNDER 15 KNOTS WITH GUSTS UNDER 20
KNOTS, HIGHEST ON TUESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ431-451>455.
DENSE FOG ADVISORY UNTIL 9 AM EDT FRIDAY FOR ANZ430-450.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...GAINES
AVIATION...GAINES/O`HARA
MARINE...GAINES/GIGI/O`HARA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
8 PM EDT FRI MAY 8 2015
.DISCUSSION... NORTH TO SOUTH MOVING CUMULUS AND STRATOCUMULUS
SHOULD DIMINISH BUT NOT TOTALLY DISSIPATE. IR SATELLITE AND 18Z GFS
MID AND UPPER LEVEL LAYERS OF MOISTURE INDICATE THAT THE MID AND
UPPER LEVEL CLOUDS ROTATING AROUND SUBTROPICAL STORM ANA, LOCATED IN
THE ATLANTIC EAST OF SAVANNAH GEORGIA, WILL CONTINUE TO CROSS
OVERHEAD THE REST OF THE NIGHT. LIGHT ONSHORE WIND BECOMES WEST TO
NORTHWEST AROUND MIDNIGHT AND REMAINS OUT OF THE NORTHWEST THE REST
OF THE NIGHT. OVERNIGHT LOWS OF MID 60S LOOKS OK.
.AVIATION...VFR.
.MARINE...THE OFFSHORE SMALL CRAFT ADVISORY EXPIRED AT 4PM AND WAS
REPLACED IT WITH A SMALL CRAFT EXERCISE CAUTION FOR SEAS TO 6 FEET.
THE LATE AFTERNOON ONSHORE WIND SHIFTS BACK TO THE WEST AND
NORTHWEST AND WILL REMAIN OUT OF THE WEST TO NORTHWEST AT 10 TO 15
KNOTS THE REST OF THE NIGHT.
PREVIOUS DISCUSSION
REST OF THIS AFTERNOON-TONIGHT...NOT MUCH CHANGE IN THE ONGOING
WEATHER THROUGH THE REMAINDER OF THE DAY AS AREA REMAINS UNDER VERY
DRY NORTHWEST FLOW ON THE FAR SOUTHWEST SIDE OF SUBTROPICAL STORM
ANA NEAR THE SOUTH CAROLINA COAST. SEA BREEZE HAS DEVELOPED ALONG
THE BREVARD AND TREASURE COAST WHICH WILL KEEP TEMPERATURES AT THEIR
CURRENT LEVELS WITH OTHER LOCATIONS MAXING OUT IN THE NEXT HOUR OR
TWO IN THE MID TO UPPER 80S.
MOSTLY CLEAR SKIES FOR TONIGHT THOUGH WITH SOME PASSING MID LEVEL
CLOUDS AS A FEW WEAK VORTICITY MAXES ROTATE AROUND THE LARGER ANA
CIRCULATION. NOT TOO MUCH MOISTURE IN THE REGION TO WORK WITH SO
DON`T EXPECT ANY LAND IMPACTS...BUT WILL SEE A FEW SHOWERS OR STORMS
OVER THE ATLANTIC AND GULF STREAM. OVERNIGHT LOWS IN THE MID-UPPER
60S.
SATURDAY...ANOTHER PLEASANT LATE SPRING DAY AS ANA MEANDERS FURTHER
NORTH AND HIGH PRESSURE BEGINS TO NOSE IN FROM THE ATLANTIC.
NORTHWEST WIND COMPONENT WILL BE LIGHTER ALLOWING FOR QUICKER
DEVELOPMENT OF THE SEA BREEZE ALONG THE ENTIRE COAST EARLY IN THE
AFTERNOON.
CONDITIONS WILL REMAIN TOO DRY FOR ANY NOTABLE RAIN CHANCES OVER
LAND THROUGH THE DAY. HIGH TEMPS REACHING INTO THE UPPER 80S/AROUND
90 INLAND AND MID-UPPER 80S COAST.
SAT NIGHT-SUN NIGHT...
THE LOW LEVEL ATLANTIC RIDGE WILL CONTINUE TO NUDGE BACK ACROSS
THE PENINSULA AS ANA LIFTS SLOWLY NORTH TOWARDS THE COASTAL
CAROLINAS. THIS WILL TURN LOW LEVEL WINDS TO SOUTHERLY WHICH WILL
CAUSE MOISTURE LEVELS TO INCREASE. PRECIPITABLE WATER VALUES IN
THE 1.3 TO 1.5 RANGE WILL KEEP POPS LOW THOUGH. EXPECT SOME MARINE
CONVECTION SAT NIGHT...THEN WITH DAYTIME HEATING...ISOLATED SEA
BREEZE SHOWERS AND STORMS SHOULD FORM...STARTING IN THE SOUTH AND
WORKING NORTHWARD.
MOS POPS ARE NEAR 20 PERCENT IN THE SOUTH AND SINGLE DIGITS IN
THE NORTH FOR SUNDAY...THEN 20 PERCENT EVERYWHERE AFTER SUNSET
SUNDAY. THINK THAT EAST/WEST COAST BOUNDARY COLLISION WOULD BE A
LITTLE EARLIER...SO HAVE PAINTED 20 POPS AREAWIDE ON SUNDAY.
WE ARE GETTING INTO THE HIGHER SUN ANGLE NOW SO MAX TEMPS WILL
START REACHING THE LOWER 90S INLAND AND UPPER 80S AT THE COAST
WITH MILD OVERNIGHT LOWS IN THE UPPER 60S TO LOWER 70S.
MON-FRI...(MODIFIED PREVIOUS DISCUSSION)
THE BLOCKING RIDGE THAT IS KEEPING ANA STATIONARY WILL BREAK DOWN
BY THE START OF THE WORK WEEK AS IT IS ERODED FROM THE WEST AND
NORTH BY AN ADVANCING FRONTAL TROF OVER THE CENTRAL PLAINS/UPR
MIDWEST. THIS WILL ALLOW ANA TO DRIFT INTO THE CAROLINAS BY
DAYBREAK MON WHERE SHE WILL START TO ACCELERATE NORTHEAST AND
EVENTUALLY BE ABSORBED BY THE LOW PRESSURE SYSTEM MOVING THROUGH
THE GREAT LAKES AND INTO NEW ENGLAND.
AS THE ABOVE SCENARIO PLAYS OUT...THE ATLC RIDGE AXIS WILL REBUILD
OVER CENTRAL FL...WHERE IT WILL BCM THE PRIMARY WX FEATURE THRU THE
MIDDLE OF NEXT WEEK. REGIONAL H100-H70 WINDS WILL SHIFT TO THE S/SE
BY DAYBREAK MON AND REMAIN IN PLACE...TAPPING AN AIRMASS OVER THE
GREATER ANTILLES THAT SIMPLY DOES NOT HAVE SUFFICIENT MOISTURE TO
SUPPORT WIDESPREAD PRECIP. RAP ANALYSIS CONTINUE TO SHOW H100-H70 RH
VALUES AOB 70PCT...NOT CONDUCIVE FOR ANYTHING MORE THAN LOW END SCT
POPS.
EVEN SO...AS THE RIDGE AXIS DRIFTS OVERHEAD...THE WX PATTERN WILL
SHIFT TO A MORE SUMMER LIKE REGIME WITH ISOLD/SCT SHRAS/TSRAS
GENERATED BY DIURNALLY DRIVEN SEA BREEZE CONVERGENCE. WILL GO WITH
20-30PCT THRU WED... HIGHER OVER THE INTERIOR GIVEN THE ANTICIPATED
SE FLOW COMPONENT...INCREASING TO 30/40PCT ON THU AS MOISTURE
LOADING SLOWLY INCREASES. MAX TEMPS NEAR CLIMO AVG (M/U80S)...MIN
TEMPS ARND 5F ABV AVG (L/M70S).
&&
.AVIATION...VFR. EAST COAST SEA BREEZE WILL PUSH ACROSS PENINSULA
AROUND SUNSET WITH LIGHT WEST WINDS OVERNIGHT. LIGHT FLOW SHOULD
ALLOW QUICKER DEVELOPMENT AND INLAND MOVEMENT OF SEA BREEZE ON
SATURDAY.
&&
.MARINE...
TONIGHT-SATURDAY...WAVE HEIGHTS HAVE STARTED TO DIMINISH AT LOCAL
BUOYS AND WILL CONTINUE TO DO SO THROUGH THE REMAINDER OF THE
AFTERNOON AND EVENING...SO WILL ALLOW CURRENT ADVISORY TO EXPIRE
IN FAVOR OF A CAUTIONARY STATEMENT FOR THIS EVENING. SLOW DOWNWARD
TREND WILL BRING SEAS TO 3-4FT WITH UP TO 5FT LATE TONIGHT AND
INTO SATURDAY. MODELS SEEM A LITTLE TOO SHORT WITH DOMINANT WAVE
PERIODS SO WILL KEEP THEM CLOSER TO OBSERVATIONS AT 9-10SEC.
WESTERN ATLANTIC RIDGE AXIS NOSING INTO AREA ON SATURDAY AS
SUBTROPICAL STORM ANA MOVES FURTHER NORTH WILL KEEP FLOW FAIRLY
LIGHT WITH PREVAILING WEST 5-10KTS OVERNIGHT BECOMING E-SE WITH SEA
BREEZE DEVELOP IN THE AFTERNOON.
SUN-WED...THE AXIS OF THE ATLANTIC HIGH PRESSURE RIDGE WILL BUILD
INTO SOUTH FLORIDA SUNDAY AND THEN ACROSS CENTRAL FLORIDA ON MON.
THIS WILL CAUSE A SOUTHEAST/SOUTH WIND FLOW TO SET UP. THE
PRESSURE GRADIENT SHOULD SUPPORT AROUND 10 KNOTS BUT THE DAILY SEA
BREEZE CIRCULATION WILL ACCELERATE SPEEDS TO NEAR 15 KNOTS EACH
AFTERNOON/EVENING. A SLIGHT CHANCE FOR OFFSHORE MOVING
THUNDERSTORMS WILL EXIST IN THE AFTERNOON/EARLY EVENING...MAINLY
SUN/MON WHILE SOUTH SOUTHWEST STEERING FLOW CONTINUES. THEN BY
TUE/WED...DAYTIME HEATING STORMS SHOULD STAY OVER THE MAINLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 64 86 68 89 / 10 10 10 20
MCO 66 91 68 92 / 0 10 10 20
MLB 65 85 70 87 / 10 10 10 20
VRB 64 86 69 88 / 10 10 10 20
LEE 67 89 69 92 / 0 10 10 20
SFB 67 89 69 91 / 0 10 10 20
ORL 68 90 70 92 / 0 10 10 20
FPR 64 87 69 88 / 10 10 10 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
IMPACT WX...PENDERGRAST
FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 PM EDT THU MAY 7 2015
.DISCUSSION...
CURRENT-TONIGHT...MOSTLY SUNNY SKIES WITH LIGHT NWRLY FLOW...THOUGH
EXPECTING NNE FLOW TO DEVELOP ALONG THE EAST COAST AND MOVE SLOWLY
INLAND. WARMER TEMPERATURES THIS AFTERNOON IN THE 80S AREAWIDE.
DRIER CONDITIONS AS WELL WITH DEWPOINT READINGS IN THE 50S TO AROUND
60 DEGREES. AN AREA OF LOW PRESSURE CONTINUES TO SPIN NEAR SOUTH
CAROLINA. DRIER AIR WILL STILL FILTER INTO THE AREA TONIGHT WITH
MOSTLY CLEAR SKIES EXPECTED. LOWS MAINLY IN L/M 60S...THOUGH COULD
SEE SOME U50S ACROSS NW PORTIONS OF VOLUSIA COUNTY.
EARLIER THIS MORNING ADDED A SMALL POP IN FOR LATE THIS
AFTERNOON/EARLY EVENING FOR OKEECHOBEE...ST. LUCIE AND MARTIN
COUNTIES. THIS BECAUSE OF MARGINAL LOW-LEVEL MOISTURE...SEA/LAKE
BREEZE INTERACTIONS AND MID-LEVEL ENERGY. STEERING FLOW FOR ANY
POTENTIAL ACTIVITY WILL BE FROM THE SOUTHWEST TOWARDS THE NORTHEAST.
LOCAL WRF/HRRR MODEL RUNS STILL SUPPORT DEVELOPMENT OF LATE DAY
CONVECTION HERE. FACTORS THAT WOULD INHIBIT DEVELOPMENT INCLUDE DRY
AIR ALOFT AND A SUBSIDENCE INVERSION.
AT THE BEACHES...OCEAN SWELLS FROM THE LOW PRESSURE OFFSHORE WILL
PRODUCE A MODERATE RISK FOR RIP CURRENTS. STRONGEST RIP POTENTIAL
IS LATE THIS AFTERNOON AND EARLY EVENING. SOME ROUGH SURF IS
STILL POSSIBLE FOR THE NRN BREVARD AND VOLUSIA COUNTY BEACHES.
FRI...THE LOW PRESSURE WILL CONTINUE TO SPIN IN PLACE NEAR THE SOUTH
CAROLINA COAST ON THIS DAY. WEAK HIGH PRESSURE WILL BE CENTERED OVER
THE EASTERN GULF. THE PRESSURE GRADIENT WILL BE WEAK ENOUGH FOR BOTH
EAST/WEST COAST SEA BREEZES TO VENTURE INLAND EARLY IN THE AFTERNOON
BACKING WINDS ALONG THE COAST TO E/ESE. LIGHT WNW/NW WINDS WILL
CONTINUE ELSEWHERE. DRIER PRECIPITABLE WATER VALUES WILL SINK SOUTH
ACROSS SOUTHWEST FLORIDA AS WRAP-AROUND MOISTURE FROM THE LOW PUSHES
INTO OUR NORTHERN COVERAGE WARNING AREA. LATEST MODEL RUNS SQUEEZE
OUT VERY LITTLE...IF ANY...QPF SO WILL DISCONTINUE ANY PRECIPITATION
FOR NOW IN THE FORECAST FOR OVER LAND. FUTURE SHIFTS CAN ADD BACK IN
IF THEY FEEL LATE DAY SEA BREEZE COLLISIONS CAN MUSTER
CONVECTION...THOUGH A LOW-LEVEL SUBSIDENCE INVERSION MAY BE TOO HARD
TO OVERCOME. AFTERNOON MIN RH VALUES FALL INTO THE 30S OVER THE
INTERIOR WHICH IS VERY DRY. ANOTHER WARM DAY IN STORE WITH HIGHS IN
THE L80S ALONG THE VOLUSIA/NORTH BREVARD COASTS...MIDDLE 80S FURTHER
SOUTH ALONG THE COAST AND UPPER 80S INLAND FROM THE COAST.
FRIDAY NIGHT-SAT...LOW PRESSURE CENTER IS FORECAST TO BE SLOW
MOVING JUST OFFSHORE THE COAST OF GEORGIA AND SOUTH CAROLINA.
THOUGH QUITE FAR REMOVED FROM THIS SYSTEM...IT WILL STILL EXERT AN
INFLUENCE ON OUR WEATHER. GENERALLY THE SOUTHWEST SIDE OF THIS
TYPE OF SYSTEM HAS LARGE SCALE SUPPRESSION. THE GFS DOES NOT SHOW
ANY DISTURBANCES ROTATING AROUND THE LOW REACHING THIS FAR SOUTH.
THE GFS SHOWS SOMEWHAT HIGHER MOISTURE WRAPPING DOWN INTO EAST
CENTRAL FLORIDA BUT PRECIPITABLE WATER VALUES ARE STILL ONLY 1.3
TO 1.4 INCHES. THE MODEL HAS LITTLE PRECIP GENERATED DURING THIS
TIME PERIOD AND MOS POPS ARE LESS THAN 10 PERCENT. SINCE INHERITED
POPS ACROSS THE NORTH WERE 20 PERCENT...HAVE MAINTAINED A SLIGHT
AFTERNOON POP THERE...BUT TRIMMED THE AREAL COVERAGE BACK
SLIGHTLY. ACTUALLY...THE LOW LEVEL CYCLONIC FLOW AND SLIGHTLY
INCREASED LOW LEVEL MOISTURE MIGHT BE MORE OF A SIGNAL OF
CONSIDERABLE STRATUS DURING THE OVERNIGHT/MORNING.
SUN-WED...(PREVIOUS DISCUSSION) THE ATLC RIDGE AXIS WILL REBUILD
OVER FL STRAITS AND LIFT STEADILY NWD THRU EARLY NEXT WEEK AS THE
CAROLINA LOW DRIFTS INTO THE MID ATLC REGION AND BECOMES ABSORBED
BY A LARGER SHORT WAVE FRONTAL TROF. REGIONAL WINDS THRU THE
H100-H70 LYR WILL SHIFT TO THE S/SE AS A RESULT...TAPPING AN
AIRMASS THAT IS STRUGGLING TO MAINTAIN HIGH ENOUGH LOW/MID LVL
HUMIDITY TO SUPPORT PRECIP. RAP ANALYSIS SHOWS H100-H70 RH VALUES
REMAIN LARGELY AOB 70PCT...THOUGH A BAND OF H85-H50 RH AOA 50PCT
EXTENDING FROM HONDURAS TO THE CENTRAL BAHAMAS COULD MAKE UP FOR
THE DRIER LOW LVLS.
WILL KEEP PRECIP IN THE FCST THRU THE MIDDLE OF NEXT WEEK...BUT
LIMITING CHANCES TO THE 20-30PCT RANGE AS THE INCREASING INFLUENCE
OF THE ATLC RIDGE WILL TEND TO BLOCK OR CANCEL OUT ANY MID/UPR LVL
DYNAMIC SUPPORT. DVLPG ONSHORE FLOW WILL KEEP TEMPS NEAR OR SLIGHTLY
ABV CLIMO AVG...AFTN MAXES IN THE M/U80S... MRNG MINS IN THE
U60S/L70S.
&&
.AVIATION...MAINLY VFR. NW WINDS EXCEPT NNE ALONG THE COAST LATER
THIS AFTERNOON AS A SEA BREEZE MARCHES SLOWLY INLAND. STILL COULD
SEE AN ISOLD LATE DAY/EARLY EVENING STORM NEAR LAKE OKEECHOBEE.
INTERESTS NEAR KOBE-KFPR-KSUA SHOULD REMAIN AWARE AS LOCAL MODEL
RUNS STILL KEEN ON THIS.
&&
.MARINE...CURRENT-TONIGHT...WINDS/SEAS WILL CONTINUE TO DECREASE
SLOWLY AS THE LOW VENTURES FURTHER NORTH TOWARD SOUTH CAROLINA AWAY
FROM ECFL. WEAK HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND WEST.
AT 4PM/20Z LIKELY TO CONTINUE THE SCA OFFSHORE NORTH OF SEBASTIAN
INLET BASED ON RECENT BUOY 41009 OBS FOR WINDS/SEAS. CAUTIONARY
STATEMENTS LIKELY TO CONTINUE FOR THE SOUTHERNMOST OFFSHORE LEG AND
POSSIBLY NEAR SHORE FOR NORTH OF SEBASTIAN INLET. JUST NOT SEEING
ENOUGH IMPROVEMENT TO TAKE THESE STATEMENTS AWAY. NW/N WINDS WILL
BACK TO WESTERLY OVERNIGHT.
FRI...LOW PRESSURE CONTINUES TO SPIN IN PLACE OFF OF THE SOUTH
CAROLINA COAST WITH WEAK HIGH PRESSURE CENTERED OFF OF THE FLORIDA
WEST COAST. W/NW WINDS WILL FALL TO AROUND 10 KTS OR LESS IN THE
AFTERNOON. THE PRESSURE GRADIENT WILL BE WEAK ENOUGH FOR THE EAST
COAST SEA BREEZE TO DEVELOP EARLY IN THE AFTERNOON BACKING WINDS
ALONG THE COAST TO E/ESE. SEAS FALLING TO 2-4 FT NEAR SHORE AND 4-5
FT OFFSHORE.
WEEKEND...LOW PRESSURE CENTER IS STILL FORECAST TO BE SLOW MOVING
NEAR THE SOUTH CAROLINA COAST. THE SYSTEM MAY STRENGTHEN SOME BUT
EXPECT IT WILL LIKELY BECOME MORE COMPACT...SO THE MAIN PERIPHERAL
IMPACTS SHOULD SHIFT NORTH OF OUR WATERS. THE MODELS SHOW ATLANTIC
SURFACE RIDGE NOSING BACK IN ACROSS THE SOUTH HALF OF THE
PENINSULA BY SUNDAY. WINDS OUT OF THE WEST ON SAT SHOULD EASE
ENOUGH FOR A SEA BREEZE CIRCULATION IN THE AFTERNOON/EVENING THEN
THE GRADIENT FLOW WILL BECOME SOUTHERLY SAT NIGHT AND SUNDAY.
SPEEDS ARE FORECAST TO BE 15 KNOTS OR LESS.
&&
.FIRE WEATHER...REMAINDER OF AFTERNOON...MIN RHS STILL FORECAST TO
DROP INTO THE L/M 30S THIS AFTERNOON ACROSS THE NRN INTERIOR WITH NW
20 FOOT WINDS TO AROUND 10 MPH.
FRI...THE LOW-LEVELS REMAIN DRY WITH AFTERNOON RH VALUES PLUMMETING
AGAIN INTO THE L/M 30S ACROSS THE I-4 CORRIDOR. THE PRESSURE
GRADIENT WILL BE LIGHT ENOUGH TO ALLOW FOR THE EAST COAST SEA BREEZE
TO DEVELOP AND MOVE SLOWLY INLAND DURING THE AFTERNOON. NW 20 FT
WINDS 5-10 MPH. HEADLINES STILL NOT NECESSARY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 62 83 66 85 / 0 20 10 20
MCO 65 88 66 90 / 0 10 0 20
MLB 64 85 65 86 / 0 10 10 20
VRB 62 86 64 87 / 10 10 10 20
LEE 64 86 67 88 / 0 20 0 20
SFB 64 88 67 89 / 0 20 10 20
ORL 66 88 67 90 / 0 20 0 20
FPR 62 86 65 87 / 20 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM-FLAGLER BEACH TO
VOLUSIA-BREVARD COUNTY LINE 20-60 NM.
&&
$$
SHORT TERM...SEDLOCK
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS KEY WEST FL
1000 AM EDT THU MAY 7 2015
.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200 MB)...LATEST
AVAILABLE IR IMAGERY AS OF 700 AM OVERLAID WITH MODEL STREAMLINE
ANALYSIS DETAILS THE CONTINUED SPLIT FLOW AROUND A DOUBLE MID AND
UPPER LOW PRESSURE SYSTEM EXTENDING FROM OHIO SOUTH SOUTHEAST TO
EAST OF SAVANNAH...WITH 30 TO 40 KNOTS AROUND THE BASE OF THE BOTTOM
OF THE TROUGH. THIS MID AND UPPER SYSTEM EAST OF NORTH FLORIDA IS
DRAWING ACROSS LOTS OF MID AND UPPER DRY AIR AS VISIBLE ON THE
LATEST WATER VAPOR IMAGERY.
AT THE SURFACE AND IN THE LOWER TO MIDDLE LEVELS...SURFACE TO 700
MB...AS OF 900 AM...1010 MB SURFACE LOW PRESSURE DUE EAST OF
SAVANNAH GEORGIA IS CONTINUING TO INCREASE IN ORGANIZATION THIS
MORNING AND THE NATIONAL HURRICANE CENTER IS INDICATING THAT THE
SYSTEM HAS A 70 PERCENT CHANCE OF DEVELOPING INTO A SUBTROPICAL
CYCLONE THROUGH 48 HOURS. GIVEN THAT SYSTEM...AND NORMAL MID MORNING
HEATING TAKING PLACE OVER THE ISLANDS AND SOUTH FLORIDA AS A
RESULT...A LIGHT TO GENTLE NORTHEAST FLOW IS IN PLACE ACROSS THE
ISLANDS AND ADJOINING WATERS...BUT STRONG SUBSIDENCE IS PROHIBITING
ANY CLOUD FORMATION ALONG THE ISLAND CHAIN ATTM. THE 12Z MORNING
SOUNDING IS SOMEWHAT MOIST IN THE LOWER LEVELS...FROM THE SURFACE TO
700 MB...AND COLUMNAR PWAT AT 1.46 INCHES...BUT THE EAST FLOW IS
ONLY THROUGH 850 MB THEN BECOMES SOUTHWEST TO WEST WITHIN MIDDLE TO
UPPER LEVEL CYCLONIC FLOW.
.CURRENTLY...AS OF 900 AM...SKIES ARE SUNNY ACROSS THE ISLANDS AND
POINTS NORTHWARD...AND MOSTLY SUNNY ACROSS LOCATIONS OVER THE
STRAITS...WITH A FEW CELLS ALONG SOME BOUNDARIES IN THE OUTERMOST
FLORIDA STRAITS. TEMPERATURES HAVE RISEN TO AROUND 80 WITH SURFACE
DEWPOINTS A TAD HIGHER THAN 24 HOURS PRIOR...IN THE LOWER 70S ACROSS
THE ISLAND CHAIN. WINDS ARE LESS VARIABLE...BUT ALSO MORE
NORTHEASTERLY THAN YESTERDAY.
.SHORT TERM...MODEL FORECAST SOUNDINS VEER THE SURFACE TO 850 FLOW
MORE TO THE SOUTHEAST TODAY...BUT EVEN IF ENOUGH HEATING BACKS THE
LOWER LEVEL WINDS TO MORE NORTHEAST...THE DRIER AIR WITIH THE
AFOREMENTIONED DEEPER CYCLONIC CIRCULATION WILL BE RATHER PROHIBITIVE
IN THE FORMATION OF WELL DEVELOPED CLOUD LINES. SO WILL MAINTAIN A
DIME POP DUE TO POSSIBLE SPRINKLES OR A VERY LIGHT ISOLATED SHOWERS.
THESE LIGHTER EAST WINDS WILL LIMIT MIXING SO HIGH TEMPERATURES
REACHING THE MID 80S...LIKE YESTERDAY...SEEMS ON TRACK.
NONHYDROSTATIC WRF ALSO THE HRRR DO NOT DEVELOP LIGHT SHOWERS ALONG
MOST OF THE KEYS...BUT A SHOWER OR TWO MAY MOVE INTO THE UPPER KEYS
LATER IN THE AFTERNOON. THE ONGOING FORECAST IS ON TRACK AND NO
CHANGES ATTM.
&&
.MARINE...LIGHT TO GENTLE BREEZES GENERALLY FROM THE EAST WILL
PREVAIL OVER ALL FLORIDA KEYS WATERS THROUGH SATURDAY. AT
TIMES...WINDS MAY BECOME LIGHT AND VARIABLE. ISOLATED SHOWERS ARE
POSSIBLE...BUT THUNDERSTORMS ARE NOT EXPECTED AT THIS TIME THROUGH
SATURDAY.
&&
.AVIATION... VFR CONDITIONS WILL PREVAIL AT EYW AND MTH TODAY AND
TONIGHT. BRIEF...MVFR CEILINGS...BASED AT AROUND 2000 FEET...ARE
CONCEIVABLE AT EYW AND MTH LATE TONIGHT. THIS POSSIBILITY IS NOT
GREAT ENOUGH TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME.
SUSTAINED EAST TO SOUTHEAST WINDS NEAR 10 KNOTS EXPECTED FROM JUST
OFF THE SURFACE TO ABOUT 3000 FEET.
&&
.CLIMATE... ON THIS DATE IN FLORIDA KEYS WEATHER HISTORY...IN
1937...4.08 INCHES OF RAIN FELL IN KEY WEST. THIS SET THE DAILY
RECORD FOR MAXIMUM RAINFALL MEASURED IN KEY WEST ON MAY 7TH...A
RECORD WHICH STILL STANDS 78 YEARS LATER. RAINFALL RECORDS AT KEY
WEST DATE BACK TO 1871.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE.........DAF
AVIATION/CLIMATE.....BS
DATA COLLECTION......SC
VISIT US ON THE WEB AT WEATHER.GOV/KEY
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AREA FORECAST DISCUSSION
NWS MELBOURNE FL
400 AM EDT THU MAY 7 2015
.DISCUSSION...
TODAY...SHORT RANGE MODELS IN GOOD AGREEMENT MOVING SFC LOW PRESSURE
AREA NORTHWARD OFFSHORE FROM THE SC COAST NEAR 32N/77W THIS
AFTERNOON. LOW LVL FLOW WILL BE FROM THE NW WITH A DRY SLOT ACROSS
NRN SECTIONS AS PRECIPITABLE WATER VALUES DROP BELOW AN INCH FOR
VOLUSIA COUNTY AND THE NRN INTERIOR. SHOULD SEE MOSTLY SUNNY SKIES
AND WARM TEMPERATURES IN THE MID TO UPPER 80S...EXCEPT SLIGHTLY
COOLER ALONG THE IMMEDIATE COAST AND BEACHES WITH A MID TO LATE
AFTERNOON SEA BREEZE DEVELOPING. GFS/NAM AND HIGH RESOLUTION MODELS
HINTING AT SOME LATE DAY CONVECTION THAT MAY TRY TO GET GOING AND
SNEAK INTO MARTIN COUNTY IN THE EVENING. WILL LEAVE FORECAST POPS
BELOW 15 PERCENT ACROSS FAR SRN SECTIONS FOR NOW. AT THE
BEACHES...OCEAN SWELLS FROM THE LOW PRESSURE OFFSHORE WILL PRODUCE A
MODERATE RISK FOR RIP CURRENTS. SOME ROUGH SURF IS EXPECTED FOR THE
NRN BREVARD AND VOLUSIA COUNTY BEACHES.
TONIGHT...DRY NW FLOW WILL CONTINUE TONIGHT WITH MOSTLY CLEAR SKIES
EXPECTED. DEPENDING ON EXTENT OF SE FL LATE DAY CONVECTION MAY NEED
A LOW POP FOR MARTIN COUNTY IN THE EVENING BUT HAVE LEFT FORECAST
DRY. LOWS MAINLY IN LOWER TO MID 60S...THOUGH COULD SEE SOME UPPER
50S ACROSS NW PORTIONS OF VOLUSIA COUNTY.
FRI-SAT... BROAD SFC LOW CENTERED OFF THE CAROLINA COAST JUST N OF
THE 30TH PARALLEL WILL PLAY AN INDIRECT ROLE IN THE LCL WX PATTERN
THRU THE END OF THE WEEK. AN H100-H70 RIDGE AXIS OVER THE MID ATLC
WILL COMBINE WITH THE LOW TO FORM A TEXTBOOK "REX" TYPE BLOCKING
PATTERN THAT WILL KEEP THE LOW NEARLY STATIONARY. THIS WILL PLACE
CENTRAL FL ON THE DESCENDING LEFT FLANK OF THE LOW...AN AREA USUALLY
ASSOCD WITH DRY AIR ADVECTION DUE TO NWRLY CONTINENTAL FLOW.
THE DEEP SOUTH WILL BE THE PRIMARY SOURCE REGION FOR CENTRAL FL WX.
RAP ANALYSIS CONTINUES TO SHOW A DRY/STABLE AIRMASS OVER GA/AL WITH
H100-H70 MEAN RH VALUES AOB 50PCT...H85-H50 VALUES AOB 20PCT...WHILE
THE ATLANTA RAOB HAS MEASURED PWAT VALUES BLO 0.7" AND A SHARP H85-
H70 SUBSIDENCE INVERSION FOR THREE STRAIGHT SOUNDINGS. EVEN SO...THE
LOW WILL BE POSITIONED CLOSE ENOUGH TO CENTRAL FL TO ALLOW SOME WRAP
AROUND MOISTURE TO WORK ITS WAY INTO THE NRN CWA ON FRI. THE LOW
ALSO WILL PREVENT THE ATLC RIDGE FROM REBUILDING OVER THE
REGION...RESULTING IN A WEAK SFC PGRAD THAT WILL ALLOW BOTH THE EAST
AND WEST COAST SEA BREEZES TO FORM.
THE 00Z MOS GUIDANCE REMAINS ON THE DRY SIDE BUT HAS MANAGED TO
RESOLVE LOW END POPS OVER THE NRN CWA ON FRI...BUT HAS TRENDED DOWN
ON SAT POPS OVER THE PAST 24HRS. DEEP LYR W/NW FLOW WILL PREVAIL
AROUND THE BASE OF THE LOW WHICH WOULD FOCUS ANY SEABREEZE MERGER
OVER THE ERN PENINSULA... IN ADDITION...THE WRLY COMPONENT WILL
GENERATE WARM TEMPS OVER THE INTERIOR WITH AFTN MAXES TOPPING OUT IN
THE U80S/L90S OUTSIDE OF THE IMMEDIATE COAST. THIS MAY BE ENOUGH TO
TRIGGER A FEW SHRAS/TSRAS THRU WEEK`S END... BUT DYNAMIC SUPPORT
WILL BE HARD TO COME BY AS THE FL PENINSULA REMAINS UNDER THE
INFLUENCE OF THE DESCENDING FLANK OF THE STORM. AS SUCH... WILL GO
WITH SLGT CHC POPS N OF U.S. HWY 192 ON FRI...AND N OF SR60 ON SAT.
SUN-WED... THE ATLC RIDGE AXIS WILL REBUILD OVER FL STRAITS AND LIFT
STEADILY NWD THRU EARLY NEXT WEEK AS THE CAROLINA LOW DRIFTS INTO
THE MID ATLC REGION AND BECOMES ABSORBED BY A LARGER SHORT WAVE
FRONTAL TROF. REGIONAL WINDS THRU THE H100-H70 LYR WILL SHIFT TO THE
S/SE AS A RESULT...TAPPING AN AIRMASS THAT IS STRUGGLING TO MAINTAIN
HIGH ENOUGH LOW/MID LVL HUMIDITY TO SUPPORT PRECIP. RAP ANALYSIS
SHOWS H100-H70 RH VALUES REMAIN LARGELY AOB 70PCT...THOUGH A BAND OF
H85-H50 RH AOA 50PCT EXTENDING FROM HONDURAS TO THE CENTRAL BAHAMAS
COULD MAKE UP FOR THE DRIER LOW LVLS.
WILL KEEP PRECIP IN THE FCST THRU THE MIDDLE OF NEXT WEEK...BUT
LIMITING CHANCES TO THE 20-30PCT RANGE AS THE INCREASING INFLUENCE
OF THE ATLC RIDGE WILL TEND TO BLOCK OR CANCEL OUT ANY MID/UPR LVL
DYNAMIC SUPPORT. DVLPG ONSHORE FLOW WILL KEEP TEMPS NEAR OR SLIGHTLY
ABV CLIMO AVG...AFTN MAXES IN THE M/U80S... MRNG MINS IN THE
U60S/L70S.
&&
.AVIATION...VFR.
&&
.MARINE...ADVISORY LEVEL SEAS WILL LINGER ACROSS THE NRN OFFSHORE
WATERS INTO THIS AFTERNOON AND EVENING...AND ACROSS THE SRN OFFSHORE
GULF STREAM WATERS THIS MORNING. WILL CONTINUE THE SCA FOR THE SRN
OFFSHORE LEG INTO MID MORNING AND DROP THE SCA FOR THE CENTRAL
OFFSHORE ZONE THIS AFTN. EXPECT SEAS TO 6-7 TO LINGER ACROSS THE NRN
OFFSHORE LEG AT LEAST INTO THIS EVENING SO HAVE EXTENDED THE SCA
THERE. WINDS UP TO 15-20 KNOTS WILL OCCUR ACROSS THE OFFSHORE
VOLUSIA WATERS TODAY WITH LIGHTER WINDS ACROSS THE SRN LEGS THIS
AFTN AROUND 10 KNOTS.
FRI-FRI NIGHT...STORM SYSTEM STALLED OFF THE CAROLINA COAST WILL
MAINTAIN A GENTLE TO MODERATE SWRLY BREEZE ACRS THE LCL ATLC...BCMG
SE NEAR THE COAST IN THE AFTN AS THE EAST COAST SEA BREEZE DVLPS.
SEAS 2-3FT NEARSHORE AND 3-4FT OFFSHORE.
SAT-MON...AS THE LOW DRIFTS UP THE CAROLINA COAST OVER THE
WEEKEND... THE ATLC RIDGE WILL REBUILD OVER THE FL STRAITS AND WORK
ITS WAY INTO CENTRAL FL BY LATE THIS WEEKEND. A GENTLE TO MODERATE
SWRLY BREEZE ON SAT WILL SHIFT MORE TO THE S/SE ON SUN AS THE RIDGE
BUILDS N. SEAS GENERALLY 2-3FT...UP TO 4FT IN THE GULF STREAM.
&&
.FIRE WEATHER... MIN RHS WILL DROP TO 30-35 PCT ACROSS THE NRN
INTERIOR THIS AFTERNOON WITH NW WINDS TO AROUND 10 MPH. NO HEADLINES
ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 62 83 66 / 0 0 20 10
MCO 87 65 88 66 / 0 0 20 0
MLB 85 64 85 65 / 0 0 20 10
VRB 84 62 86 64 / 0 10 20 10
LEE 86 64 86 67 / 0 0 20 0
SFB 87 64 88 67 / 0 0 20 10
ORL 87 66 88 67 / 0 0 20 0
FPR 85 62 86 65 / 0 10 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR SEBASTIAN
INLET TO JUPITER INLET 20-60 NM.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR VOLUSIA-
BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR FLAGLER
BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM.
&&
$$
SHORT TERM/AVIATION...VOLKMER
LONG TERM/IMPACT WX....BRAGAW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1051 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE OFF THE GEORGIA AND SOUTH CAROLINA COAST WILL SLOWLY
MOVE NORTH TODAY THEN TO COASTAL SOUTH CAROLINA FRIDAY. THE LOW
WILL STALL OFFSHORE OF SC THROUGH SATURDAY WITH CHANCES OF SHOWERS
AND THUNDERSTORMS CONTINUING. A COLD FRONT WILL CROSS THE AREA
EARLY NEXT WEEK WITH CHANCES OF SHOWERS AND THUNDERSTORMS
REMAINING IN THE FORECAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE OFFSHORE SOUTH CAROLINA MOVING VERY SLOWLY TO THE
NORTH. MOISTURE FLUX TRANSPORT FOCUSED ACROSS THE NORTH COASTAL
REGION SOUTH CAROLINA. AIR MASS ACROSS MIDLANDS REMAINS FAIRLY DRY
WITH LOW WITH PRECIPITABLE WATER BELOW 1.00 INCH.
HOWEVER...LATEST RADAR TRENDS SUGGEST SHOWERS ARE MOVING WEST INTO
EAST CENTRAL MIDLANDS. LATEST HRRR MODEL SUGGEST A BAND OR TWO OF
SHOWERS MAY SPREAD WEST INTO COLUMBIA BY EARLY AFTERNOON.
THEREFORE...RAISED POPS TO CHANCE CENTRAL AND LIKELY EAST THROUGH
AFTERNOON. TEMPERATURES WILL BE TRICKY ONCE AGAIN THIS AFTERNOON
DEPENDING ON CLOUD COVER AND CHANCES FOR SHOWERS. TEMPERATURES
MAY STRUGGLE TO RISE EAST OF COLUMBIA.GUIDANCE AND LOCAL NUMBERS
RANGING FROM THE MIDDLE 70S ACROSS THE EAST TO MIDDLE 80S ACROSS
THE CSRA. HAVE CONTINUED WITH THIS TREND OF LOWER TEMPERATURES
ACROSS THE EASTERN MIDLANDS WITH MID/UPPER 70S AND WARMEST
TEMPERATURES ACROSS THE CSRA WITH LOWER 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT THE LOW WILL MOVE SLOWLY NORTHWARD AND THEN STALL OFFSHORE
OF MYRTLE BEACH BY FRIDAY INTO FRIDAY NIGHT. THE MODELS HAVE
CONTINUED WITH THEIR TREND OF THIS SLOW NORTHWARD MOVEMENT AND
STALL ALONG THE SC COAST. THIS WILL CONTINUE TO SPREAD PLENTY OF
MOISTURE INTO THE FORECAST AREA. THE LOW IS EXPECTED TO
STRENGTHEN AS IT MOVES NORTHWARD AS IT WILL BE OVER THE GULF
STREAM WITH SEA SURFACE TEMPERATURES IN THE UPPER 70S. NATIONAL
HURRICANE CENTER CONTINUES TO MONITOR THIS SYSTEM AND CURRENTLY
FORECASTS A 70 PERCENT CHANCE OF DEVELOPING INTO A TROPICAL
SYSTEM. ALTHOUGH THERE WILL BE SOME WIND AND TIDAL CONCERNS ALONG
THE COAST THE MAIN CONCERN FOR THE MIDLANDS AND CSRA WILL BE
POTENTIAL FOR RAIN. DEPENDING ON THE EXACT TRACK OF THE
SYSTEM...SOME PORTIONS OF THE EASTERN MIDLANDS/PEE DEE COULD SEE
SOME LOCALLY HEAVY RAIN. HEAVIEST RAINFALL WILL BE ACROSS THE
EASTERN MIDLANDS WITH UP TO ONE HALF INCH POSSIBLE THROUGH
FRIDAY...WITH AROUND ONE TENTH OF AN INCH FOR THE MIDLANDS.
CONCERN WITH RAINFALL WILL BE BREAKS IN THE CLOUDS ALLOWING FOR
HEATING AND DEVELOPMENT OF THUNDERSTORMS...WHICH WOULD CHANGE THE
ACCUMULATIONS GREATLY. HIGH TEMPERATURES WILL BE IN THE UPPER 70S
TO LOWER 80S IN THE EASTERN MIDLANDS WITH LOWER TO MIDDLE 80S
ELSEWHERE AND OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS HAVE COME INTO BETTER AGREEMENT WITH THE COASTAL LOW
LINGERING WITH A COLD FRONT CROSSING THE REGION EARLY NEXT WEEK.
COASTAL LOW WILL REMAIN QUASI-STATIONARY OFFSHORE OF SC SATURDAY
THEN BEGIN SLOWLY EJECTING NORTHWARD SUNDAY THROUGH MONDAY. THE
GFS REMAINS THE SLOWEST EJECTING THE LOW SO HAVE TRENDED THE
SATURDAY THROUGH SUNDAY TIME FRAME TOWARD THE ECMWF. PLENTY OF
MOISTURE WILL LINGER INTO NEXT WEEK WITH A COLD FRONT CROSSING THE
LOWER MS VALLEY MONDAY AND MOVING INTO THE FORECAST AREA TUESDAY.
THIS WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE
FORECAST WITH HIGH PRESSURE TRYING TO PUSH DRIER AIR INTO THE
REGION FOR WEDNESDAY. GFS AND ECMWF DIFFER ON HOW FAST AND FAR
SOUTH/EAST THE FRONT WILL PUSH. ECMWF HINTS AT THE FRONT BECOMING
STATIONARY ACROSS THE AREA. CONCERN FOR SATURDAY AND SUNDAY WILL
BE POSITION AND PROGRESSION OF THE COASTAL LOW. WITH BREAKS IN THE
CLOUDS AND DIURNAL HEATING THUNDERSTORMS WILL BE POSSIBLE AND THE
POTENTIAL FOR LOCALLY HEAVY RAIN...MAINLY OVER THE EASTERN
MIDLANDS...WILL CONTINUE. WILL CONTINUE TO MONITOR AND ADJUST
RAINFALL AMOUNTS AS CONFIDENCE INCREASES IN MODELS. TEMPERATURES
THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR FORECAST.
AN AREA OF LOW PRESSURE OFF THE GEORGIA COAST WILL CONTINUE TO DRIFT
NORTHWARD THROUGH FRIDAY. MID AND HIGH LEVEL CLOUDS ASSOCIATED WITH
THIS DISTURBANCE WILL AFFECT THE TAF SITES TODAY. CANNOT RULE OUT
SCATTERED SHOWERS MAINLY NEAR OGB TERMINAL AFTER 18Z...BUT LIKELY
NOT TO RESULT IN RESTRICTIONS. GUIDANCE ALSO INDICATING THAT SOME
STRONGER WINDS COULD DEVELOP AFTER 16Z WITH GUSTS AROUND 20 KNOTS.
LOW CLOUDS COULD BEGIN MOVING INTO THE MIDLANDS TAF SITES BEFORE
DAWN FRIDAY MORNING...THOUGH CONFIDENCE IS TOO LOW TO MENTION
RESTRICTIONS ATTM.
EXTENDED AVIATION OUTLOOK...MODELS INDICATE THE SURFACE LOW
REMAINING OFF THE COAST SC AND TAKING IT TOWARD THE OUTER BANKS OF
NC FOR THE WEEKEND. COULD SEE INTERMITTENT RESTRICTIONS FRIDAY
THROUGH MONDAY. SCATTERED CONVECTION POSSIBLE...ESPECIALLY FROM CAE
AND OGB ON EASTWARD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS BOISE ID
959 AM MDT THU MAY 7 2015
.DISCUSSION...PRECIPITATION SHIELD SOUTH OF A LINE FROM KUNA
THROUGH MOUNTAIN HOME TO JEROME AT 940 AM WILL LIFT SLOWLY NORTH
TODAY ACROSS CENTRAL IDAHO. UNDER THIS AREA STEERING WINDS ARE
LIGHT /NE TO SE 15 MPH/ AND HIGH TEMPERATURES WILL BE COOL /UPPER
40S AND 50S/. SO...STABILITY PARAMETERS AND LATEST HRRR RUNS DO
NOT SUPPORT THUNDERSTORMS THERE. THUNDERSTORMS ALREADY IN EASTERN
NV IN THE EAST FLANK OF THE UPPER LOW ARE ASSOCIATED WITH AN UPPER
IMPULSE SEEN ON WATER VAPOR IMAGERY AND SURFACE LOW. THE UPPER
IMPULSE IS EXPECTED TO PIVOT AROUND THE LOW AND BRING A SMALL
THREAT OF THUNDERSTORMS TO THE WEST MAGIC VALLEY AND AREAS SOUTH
AND WEST TO THE ID-NV BORDER...UNTIL AROUND 02Z OR 8 PM MDT. MINOR
UPDATES REFINE THUNDERSTORM AREA IN THE SHORT TERM. REMAINDER OF
THE FORECAST THROUGH THIS WEEKEND IS ON TRACK WITH...UNSETTLED
WEATHER MAINLY OVER IDAHO THROUGH FRIDAY EVENING AND DRY WEATHER
EVEN IN THE MOUNTAINS BY SUNDAY....IS ON TRACK.
&&
.AVIATION...VFR. BROKEN TO OVERCAST MID LEVEL CLOUDS WITH ISOLATED
SHOWERS OVER SOUTHWEST IDAHO. SHOWER COVERAGE WILL INCREASE TO
SCATTERED THIS AFTERNOON...MAINLY ACROSS SOUTHWEST IDAHO. ISOLATED
THUNDERSTORMS DEVELOPING LATE THIS AFTERNOON ALONG THE NEVADA
BORDER. SURFACE WINDS NORTHWESTERLY 10-15 KNOTS WITH GUSTS TO 20
KTS. WINDS ALOFT NORTHWESTERLY AROUND 10 KNOTS UP THROUGH 10K FEET
MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH FRIDAY...MODELS CONTINUE TO HAVE GOOD
OVERALL CONSISTENCY IN THE SHORT TERM WITH THE LARGE-SCALE FLOW
AND EVEN SOME SURFACE FEATURES...BUT THE QPF FIELDS ARE CHANGING
DRAMATICALLY FROM RUN TO RUN AND DIFFER GREATLY BETWEEN MODELS. WE
PUT A GREAT DEAL OF WEIGHT ON THE SREF OUTPUT FOR THIS PACKAGE BUT
STILL RETAINED SOME OF THE DETERMINISTIC MODEL OUTPUT TO TRY TO
MAINTAIN SOME HIGHER AMOUNTS IN THE FORECAST. HOWEVER...CONFIDENCE
IN LOCATION OF MAX PRECIP OVER THE NEXT 36 HOURS IS WELL BELOW
NORMAL. THERE IS STILL NOTABLE CONVECTIVE POTENTIAL IN THE SE
PORTION OF THE CWA THIS AFTERNOON AND EVENING...AND AGAIN
TOMORROW. THE ONE CHANGE WAS TO PUT A SLIGHT CHANCE OF
THUNDERSTORMS BACK INTO THE TREASURE VALLEY AS WE EXPECT SOME
STORMS TO ADVECT OFF THE MOUNTAINS IN THE EASTERLY FLOW. ALSO...
WITH DEWPOINTS RISING THIS MORNING...THERE SEEMS TO BE ENOUGH OF A
THREAT TO WARRANT A MENTION. THERE WERE LARGE DISCREPANCIES IN THE
TEMP FORECASTS FROM THE GFS TO NAM FOR TODAY/S HIGHS THIS TIME
YDAY...BUT THEY HAVE LARGELY COME TO THE CENTER IN THE LATEST
RUNS. THIS IS WHERE OUR FORECAST HAS BEEN FOR SEVERAL DAYS
NOW...SO THERE WAS VIRTUALLY NO CHANGE IN THE TEMP FORECAST. WE
WILL SEE A SLOW WARMING TREND ON FRIDAY AS THE UPPER LOW MOVES
AWAY FROM THE AREA AND HEIGHTS RISE. THUNDERSTORMS WILL AGAIN BE
IN THE FORECAST FRIDAY AFTERNOON FOR THE SOUTHEAST PORTION OF THE
CWA. WINDS WILL NOT BE STRONG IN THE SHORT TERM...BUT WILL BLOW
NEAR 20 MPH IN SE OREGON THIS AFTERNOON...AND AS ALMOST ALWAYS
WILL BE GUSTY NEAR STORMS OR SHOWERS THAT FORM.
LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...MODELS IN RELATIVELY
GOOD AGREEMENT OVER THE WEEKEND WITH TIMING AND PLACEMENT DIFFERENCE
SHOWING UP OVER THE REGION BY EARLY NEXT WEEK. THE ONE CONSISTENT
THING WITH THE MODELS IS THAT THE PATTERN WILL REMAIN ACTIVE.
UPPER LEVEL LOW CENTERED OVER SOUTHERN NEVADA FRIDAY NIGHT WILL
MOVE EAST TO THE FOUR CORNERS AREA AND WEAKEN WITH A BROAD OPEN
TROUGH OVER THE FOUR CORNER STATES BY SATURDAY AFTERNOON. AS THIS
LOW MOVES EAST PRECIPITATION OVER THE FORECAST AREA WILL DECREASE
FROM WEST TO EAST WITH SLIGHT CHANCE POPS OVER EASTERN ZONES OF
SOUTHWEST IDAHO. SATURDAY NIGHT AND SUNDAY THE LOW WILL CONTINUE
TO WEAKEN AND MOVE TO THE NORTHEAST AS AN UPPER LEVEL RIDGE BUILDS
OVER THE INTERMOUNTAIN REGION. THIS RIDGE WILL BRING MOSTLY DRY
CONDITIONS TO THE FORECAST AREA. SUNDAY NIGHT INTO MONDAY MODELS
BEGIN TO DIVERGE ON TIMING AND PLACEMENT OF THE NEXT UPPER LEVEL
TROUGH AND ASSOCIATED LOW THAT WILL BE MOVING INTO THE WEST COAST.
LATEST GFS CONTINUES TO DIG THE LOW SOUTH ALONG THE COAST BUT THE
NEWEST ECMWF NOW HOLD THE LOW OFF THE WASHINGTON COAST WITH LITTLE
CHANGE IN EITHER MODEL FROM MONDAY THROUGH TUESDAY. WITH THE
DIFFERENCES BETWEEN THE MODELS OF THE PLACEMENT OF THE LOW ALSO
MEANS DIFFERENCES IN WHERE PRECIPITATION WILL FALL. WILL LITTLE
CONFIDENCE IN THE MODELS THAT FAR OUT DECIDED TO GO TOWARDS A
MODEL BLEND. WEDNESDAY GFS HAS THE LOW OVER SOUTHERN CALIFORNIA/
SOUTHERN NEVADA WHILE THE ECMWF SHIFTS THE LOW WEST OFF THE
COAST. WITH LOW CONFIDENCE IN THE MODELS WILL CONTINUE WITH A
MODEL BLEND. TEMPERATURES THROUGH THE EXTENDED WILL AVERAGE A FEW
DEGREES ABOVE NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....JS
PREV SHORT TERM...SP
PREV LONG TERM....JA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CDT THU MAY 7 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 259 PM CDT THU MAY 7 2015
SCATTERED SHOWERS AND THUNDERSTORMS OVER MO AND IA INTO INTO THE MS
RIVER VALLEY OF IL WILL SPREAD NE ACROSS CENTRAL IL LATE THIS
AFTERNOON AND INTO TONIGHT. MODELS HAVE THE CONVECTION WEAKENING
AFTER SUNSET WITH LOSS OF INSTABILITY AND BECOMING MORE ISOLATED IN
EASTERN IL OVERNIGHT SO HAVE TRENDED POPS FROM 50-60% IN WESTCENTRAL
IL LATE THIS AFTERNOON AND TONIGHT TO ISOLATED IN EASTERN IL BY
OVERNIGHT. SPC HAS MARGINAL RISK WEST OF A PEORIA TO JACKSONVILLE
LINE WHERE CAPES PEAK FROM 1200-1800 J/KG THROUGH 00Z/7 PM. MAINLY
SMALL HAIL POSSIBLE THIS AFTERNOON AND EARLY EVENING UNTIL SUNSET.
GETTING A FEW HALF TO THREE QUARTER INCH SIZE HAIL REPORTS PAST HOUR
OVER NE MO AND FUNNEL CLOUD REPORT NEAR HANNIBAL MO. COLD FRONT JUST
NW OF IA INTO CENTRAL KS TO PUSH INTO SE IA AND NW MO BY SUNRISE
FRI. MILD LOWS MOSTLY IN THE MID 60S TONIGHT WITH BREEZY SSW WINDS
10-20 MPH AND GUSTS OF 20-35 MPH THIS AFTERNOON DIMINISHING TO
AROUND 10 MPH AFTER SUNSET.
&&
.LONG TERM...(FRIDAY THROUGH THURSDAY)
ISSUED AT 259 PM CDT THU MAY 7 2015
AN ACTIVE AND UNSEASONABLY MILD WEATHER PATTERN IS EXPECTED TO
PERSIST ACROSS CENTRAL AND SOUTHEAST ILLINOIS THROUGH MONDAY. MAIN
FORECAST CONCERN REVOLVES AROUND SHOWER/THUNDERSTORM TIMING AND
INTENSITY THROUGH MONDAY. UNFORTUNATELY, THE LIMITS OF
PREDICTABILITY WITH CONVECTIVE WEATHER MAKE THE DETAILS TOUGH TO
PINPOINT TOO FAR OUT.
THE FRONTAL BOUNDARY THAT CURRENTLY EXTENDS THROUGH THE UPPER
MIDWEST AND INTO THE SOUTHERN PLAINS WILL CONTINUE TO MAKE SLOW
EASTWARD PROGRESS THE NEXT FEW DAYS, EVENTUALLY CLEARING THE AREA
ON MONDAY. THE PASSAGE OF THIS FRONT WILL END THE UNSETTLED
WEATHER PATTERN AND PUSH TEMPERATURES BELOW NORMAL FOR MUCH OF
NEXT WEEK.
EXPECT A DIURNALLY INDUCED MAXIMUM COVERAGE OF SHOWERS/STORMS INTO
SATURDAY AS THERE DOES NOT APPEAR TO BE A SIGNIFICANT UPPER LEVEL
FEATURE TO FOCUS PRECIPITATION BY THEN, AND NO SIGNIFICANT NOCTURNAL
LOW LEVEL JET IS EXPECTED EITHER. THE SEVERE THREAT THROUGH SATURDAY
ALSO LOOKS TO BE SPOTTY AT BEST GIVEN WEAK SHEAR PROFILES AND MOSTLY
MODEST INSTABILITY. WHILE THE INSTABILITY IS LIKELY TO BECOME MUCH
BETTER BY SATURDAY AFTERNOON, PEAKING IN EXCESS OF 1500 J/KG, SHEAR
PROFILES STILL DON`T SUPPORT ORGANIZED SEVERE WEATHER.
THE CUTOFF UPPER LOW, CURRENTLY ALONG THE CALIFORNIA COAST, WILL
FINALLY GET MOVING AND PASS WEST/NORTH OF THE FORECAST AREA SUNDAY
INTO MONDAY. THIS IS THE FEATURE THAT WILL EVENTUALLY DRIVE THE
SURFACE FRONT THROUGH THE AREA. ITS APPROACH/PASSAGE WILL ALSO
PROVIDE ENHANCED SHEAR PROFILES LOCALLY (TO GO ALONG WITH GOOD
DIURNAL INSTABILITY) IN THE WEST ON SUNDAY AND AREAWIDE FOR MONDAY.
THESE DAYS WILL BE OUR MOST LIKELY TIME FOR SEVERE STORMS,
ESPECIALLY MONDAY.
ONCE THE COLD FRONT CLEARS THE AREA MONDAY, QUIET AND COOLER WEATHER
WILL BE WITH US FOR MUCH OF THE WEEK. DAILY HIGH TEMPERATURES THAT
HAD BEEN MAINLY IN THE 80S THE PAST SEVERAL DAYS, WILL FALL INTO THE
60S, WHICH IS BELOW NORMAL FOR EARLY/MID MAY. THE COOLER/QUIETER
WEATHER WILL ARRIVE ALONG WITH A STRONG CANADIAN AREA OF HIGH
PRESSURE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1259 PM CDT THU MAY 7 2015
HAVE VCTS AT PIA AND SPI STARTING AT 23Z INTO MID EVENING AND AT
BMI AND DEC STARTING AT 01Z FOR THIS EVENING PER LATEST HRRR AND
RAP MODEL RUNS. THESE MODELS KEEP CMI DRY NEXT 24 HOURS PROTECTED
BY SURFACE AND UPPER LEVEL RIDGE IN THE SOUTHEAST STATES. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS LIKELY WILL DEVELOP FRIDAY
AFTERNOON MAINLY AFTER 18Z/FRI WITH BEST CHANCES OVER WESTERN
AIRPORTS AGAIN CLOSER TO APPROACHING FRONTAL BOUNDARY MOVING INTO
SE IA AND NW MO FRIDAY MORNING. BREEZY SSW WINDS 14-20 KTS WITH
GUSTS 24-30 KTS THIS AFTERNOON TO DIMINISH TO 5-10 KTS AFTER
SUNSET OUT OF THE SOUTH AND THEN SW AROUND 10 KTS FRI MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...BAK
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
100 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1045 AM CDT THU MAY 7 2015
FORECAST LOOKS ON TRACK TODAY AS ONLY MINOR ADJUSTMENTS NEEDED.
ANOTHER WARM AND RATHER HUMID SUMMER LIKE DAY EXPECTED WITH HIGHS
IN THE LOW TO MID 80S. HAVE 20-40% CHANCE OF SHOWERS AND
THUNDERSTORMS DURING MID/LATE AFTERNOON FROM LINCOLN WESTWARD WITH
HIGHEST POPS WEST TOWARD THE MS RIVER VALLEY. SOUTH BREEZES
OF 10-20 MPH WITH GUSTS 20-30 MPH EXPECTED AGAIN TODAY AND WINDS
ALREADY GUSTING IN THE 20S AT LATE MORNING WEST OF I-57.
&&
.SHORT TERM...(TODAY)
ISSUED AT 335 AM CDT THU MAY 7 2015
A COLD FRONTAL BOUNDARY ORIENTED NORTH-SOUTH ACROSS THE NORTHERN AND
CENTRAL PLAINS EARLY THIS MORNING WILL APPROACH SLOWLY THROUGH THE
DAY WHILE A LARGE SCALE TROUGH OVER THE WESTERN U.S. AND RIDGE OVER
THE EASTERN U.S. PROVIDE FOR GENERAL SOUTHWESTERLY FLOW ACROSS THE
CENTRAL UNITED STATES. INCREASING LOW AND MID-LEVEL MOISTURE WILL
CREATE ENOUGH INSTABILITY OVER WESTERN PORTIONS OF THE STATE FOR
ISOLATED TO SCATTERED THUNDERSTORMS BY AFTERNOON...ALTHOUGH MOST OF
THE CONVECTIVE ACTIVITY SHOULD FOCUS FARTHER WEST CLOSER TO THE
FRONTAL BOUNDARY EDGING INTO IA/MO. WARM HIGH TEMPERATURES WILL
CONTINUE TODAY WITH HIGHS IN THE MID 80S. EXPECT BREEZY SOUTH WINDS
10-15 MPH.
EARLY MORNING A FEW SHOWERS ARE POSSIBLE AS AN INITIAL UPPER LEVEL
DISTURBANCE TRANSLATES FROM SW MO INTO WESTERN IL MAINLY WEST OF THE
ILLINOIS RIVER.
.LONG TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU MAY 7 2015
NOT A LOT OF CHANGES IN THE SHORT AND MEDIUM RANGE FORECASTS WITH
THE MODELS MAINTAINING THE SOUTHWESTERLY FLOW PATTERN THROUGH THE
WEEKEND. STARTING TO SEE DISPARITY IN THE LONGER RANGE ON THE OTHER
SIDE OF SUNDAY/MONDAY WITH THE PROGRESSION OF THE UPPER WAVE. GFS
KEEPS THE LOW WRAPPED UP AND CUT OFF, POTENTIALLY INTRODUCING MORE
AND COOLER AIRMASS INTO THE MIDWEST IN THE WAKE OF IT...WHILE THE
ECMWF IS OPENING THE LOW AND FOR NOW, REMAINING PRETTY CONSISTENT.
STORM SYSTEM TO THE WEST SLOWLY APPROACHING THE FA TODAY WILL SPREAD
PRECIP OVER THE FA FROM WEST TO CENTRAL MAINLY TONIGHT...AND
TOMORROW BECOMING MORE WIDESPREAD ACROSS THE AREA AS THE FRONT
SETTLES INTO THE REGION. LOW OVER THE PAC NW DIGGING IN TODAY AND
TONIGHT OVER THE DESERT SW AND ESTABLISHING A SOUTHWESTERLY FLOW
PATTERN INTO THE MIDWEST. A SERIES OF SMALL WAVES ROTATING AROUND
THE MAIN TROF TO THE SOUTHWEST WILL MOVE ALONG INVOF THE BOUNDARY
WITH THE BOUNDARY PROVIDING FOCUS FOR SHOWERS AND THUNDERSTORMS.
EXPECTING TO KEEP THE PATTERN WET THROUGH THE WEEKEND, THOUGH THERE
WILL LIKELY BE BREAKS IN SOME OF THE RAINFALL. FINALLY SEE THE MAIN
UPPER LOW LIFT OUT OF THE SW SUN NIGHT/MONDAY...WITH A STORMY
OUTLOOK FOR THE SFC AS A TRUE COLD FRONT PUSHES THROUGH THE REGION.
TIMING FOR THE BOUNDARY ON MONDAY WILL BE CLOSELY WATCHED AS THERE
IS A DECENT CHANCE FOR SOME OF THE STORMS TO BECOME SEVERE WITH A
MIX OF INSTABILITY WITH STRONG SOUTHERLY FLOW AHEAD OF THE
SYSTEM...AND DEEP LAYER SHEAR WITH THE UPPER LOW LIFTING OUT.
COOLER TEMPS AND DRY WEATHER EXPECTED FOR TUE/WED AS THE AIRMASS
SHIFTS EAST AND COLDER AIR FILTERS INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1259 PM CDT THU MAY 7 2015
HAVE VCTS AT PIA AND SPI STARTING AT 23Z INTO MID EVENING AND AT
BMI AND DEC STARTING AT 01Z FOR THIS EVENING PER LATEST HRRR AND
RAP MODEL RUNS. THESE MODELS KEEP CMI DRY NEXT 24 HOURS PROTECTED
BY SURFACE AND UPPER LEVEL RIDGE IN THE SOUTHEAST STATES. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS LIKELY WILL DEVELOP FRIDAY
AFTERNOON MAINLY AFTER 18Z/FRI WITH BEST CHANCES OVER WESTERN
AIRPORTS AGAIN CLOSER TO APPROACHING FRONTAL BOUNDARY MOVING INTO
SE IA AND NW MO FRIDAY MORNING. BREEZY SSW WINDS 14-20 KTS WITH
GUSTS 24-30 KTS THIS AFTERNOON TO DIMINISH TO 5-10 KTS AFTER
SUNSET OUT OF THE SOUTH AND THEN SW AROUND 10 KTS FRI MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...ONTON
LONG TERM...HJS
AVIATION...07
AREA FORECAST DISCUSSION
NWS TOPEKA KS
410 PM CDT Thu May 7 2015
.SHORT TERM...(This Evening through Friday)
Issued at 405 PM CDT THU MAY 7 2015
Challenging forecast again tonight with somewhat disorganized
convection this evening and overnight. Band of stronger
thunderstorms forming in weak convergence and max instability axis
from central KS to southeast Nebraska. 0-6 km bulk shear in that
area in the 30 kt range while 0-1 km shear is weak. Storms could
display some organization with hail and wind the main severe
threats. Very heavy rain may also be a concern with slow storm
movement and the potential for some training. Showers and isolated
thunderstorms in east central KS in an area of weak isentropic lift
and have persisted for awhile today and are not going away by late
afternoon. RAP and last few HRRR runs have done alright with
development along boundary/instability axis and have this area
persist and then move southeast overnight. Heavy rain will be the
main threat later tonight.
Challenge for Friday is how much remnant showers/storms will occur
in the morning. Believe best chances of persistence into the
morning will be in east central Kansas. Several models are then
supportive of a shortwave impulse coming out of the southwest moving
into forecast area around early evening on Friday.
.LONG TERM...(Friday Night through Thursday)
Issued at 405 PM CDT THU MAY 7 2015
By Friday evening severe convection will form along the dry line
across far southwest KS. That area of convection will likely expand
in coverage as it moves northeastward through the overnight hours.
At the surface a warm front will begin to lift back northward into
the day Saturday. Convection looks to generally track along this
front passing through most of southern KS. Lapse rates decrease
during the evening hours as mid to upper 60 dewpoints spread into
the southern half of the forecast area. This places cape values in
the 1500-2500 j/kg valid at 00Z. Models agree that the cape will
decrease, but remains somewhat modest as the deep layer shear
increases to around 35 kts. The NAM is the most aggressive with an
increasing low level jet developing over southern KS as the storms
approach the area. Given the parameters in place strong to severe
storms are possible. The models are fairly consistent in bringing a
decent amount of QPF through the area by 12Z Sat. Flooding will
definitely be a concern especially given the recent rainfall and
saturated ground at some locations. There is a chance for a dry
period during the day Sat before the next round associated with the
main mid level low ejecting out of the Rockies. The chance for
severe storms overnight Saturday is greater across the area given
the dry line will be further east into central KS. Also, the deep
layer shear looks to be closer to 50 kts and the cape remains as
high as 2000 j/kg. Low level jet increases again leading to wind
profile favorable for supercells and possibly tornadoes. This threat
may diminish during the early morning hours as depicted by the NAM,
which barely brings QPF into the area overnight. The dry line
continues eastward as the main mid level low lifts through NE and
SD. By the time the atmosphere destabilizes the dry line will be
located somewhere in far eastern KS where storms are likely to form.
The vertical wind profile appears to be more unidirectional out of
the southwest, which is more parallel to the boundary possibly
leading to more cell interaction. So discrete supercells initially
may quickly transition into a cluster or line, and there is plenty
of cape and deep layer shear for these storms to be severe Sun
afternoon.
The upper level system finally begins to lift northeast late Sunday
into Monday and becomes and open wave by Tuesday over the Upper
Mississippi Valley. Dry and stable conditions are left in its wake,
which will be very needed by this point as the area needs to dry out
a bit before the next system develops. The upper levels will
transition to a more zonal flow pattern over the Central Plains.
Meanwhile, the next trough will begin to set up over the Western
CONUS. At this point, it could be a similar upper level pattern
developing as has recently been in place. However, at this point,
it doesn`t appear moisture recovery, necessary for as wet of a
pattern, will be in place at least through Thursday night. A quick
upper level shortwave may be ejected out of the Southern Rockies in
the afternoon time frame on Wednesday and possibly interact with a
weak warm boundary near the KS/NE border. There could be some
isolated convection flare up, but at this point it doesn`t appear to
be too noteworthy of an event. Will have to stay tuned as this is
too far out to have much confidence at this point in how exactly it
will play out.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1242 PM CDT THU MAY 7 2015
Deck of MVFR stratus hanging in over central KS and KMHK. Expect
this to lift early this afternoon. Thunderstorm chances begin
again by mid to late afternoon at MHK and early evening farther
east at FOE and TOP. Other than in thunderstorms, could get
another stratus deck in later tonight with MVFR ceilings.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Drake/Sanders
AVIATION...GDP
AREA FORECAST DISCUSSION
NWS JACKSON KY
940 PM EDT FRI MAY 8 2015
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 725 PM EDT FRI MAY 8 2015
CONDITIONS WILL REMAIN GENERALLY VFR THROUGH THE AVIATION PERIOD.
AN EXCEPTION BEING A VERY SMALL CHANCE FOR A THUNDERSTORM AT THE
TAF SITES THIS EVENING AND AGAIN SATURDAY AFTERNOON WHICH WILL BE
KEPT OUT OF THE OFFICIAL TAFS. IN ADDITION THERE IS THE POTENTIAL
FOR SOME MVFR FOG AT THE LOZ...SME...AND SYM SITES TOWARD DAWN
SATURDAY WHICH HAVE BEEN ADDED TO THOSE TAFS AS A TEMPO GROUP.
WINDS WILL REMAIN MAINLY LIGHT AND VARIABLE THROUGH THE BULK OF
THE PERIOD BEFORE TURNING TO THE SOUTHWEST AND INCREASING FROM THE
SOUTHWEST BY MIDDAY SATURDAY IN THE SOUTHWEST PARTS OF THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
724 PM EDT FRI MAY 8 2015
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 725 PM EDT FRI MAY 8 2015
CONDITIONS WILL REMAIN GENERALLY VFR THROUGH THE AVIATION PERIOD.
AN EXCEPTION BEING A VERY SMALL CHANCE FOR A THUNDERSTORM AT THE
TAF SITES THIS EVENING AND AGAIN SATURDAY AFTERNOON WHICH WILL BE
KEPT OUT OF THE OFFICIAL TAFS. IN ADDITION THERE IS THE POTENTIAL
FOR SOME MVFR FOG AT THE LOZ...SME...AND SYM SITES TOWARD DAWN
SATURDAY WHICH HAVE BEEN ADDED TO THOSE TAFS AS A TEMPO GROUP.
WINDS WILL REMAIN MAINLY LIGHT AND VARIABLE THROUGH THE BULK OF
THE PERIOD BEFORE TURNING TO THE SOUTHWEST AND INCREASING FROM THE
SOUTHWEST BY MIDDAY SATURDAY IN THE SOUTHWEST PARTS OF THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JVM
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...JVM/GREIF
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1126 AM CDT THU MAY 7 2015
.DISCUSSION...
AS EXPECTED WE ARE SEEING ISOLD TO WIDELY SCATTERED SHWRS POPPING
UP AREA WIDE LATE THIS MORNING AND THUS HAVE EXPANDED POPS TO
INCLUDE ALL OF OUR REGION FOR THE REMAINDER OF THIS MORNING. AS
INSTABILITY CONTINUES TO INCREASE LATER TODAY...EXPECT THAT SOME
ISOLD TSTMS WILL ALSO BE POSSIBLE WITH EXISTING OUTFLOW BOUNDARIES
STILL PRESENT FROM EARLIER CONVECTION WITH DECAYING MCS OVER OUR
FAR NRN TIER COUNTIES. KEPT POPS UNCHANGED FOR THIS AFTERNOON WITH
LOW CHANCE FOR MOST AREAS AND JUST SLIGHT CHANCE OVER OUR FAR ERN
SECTIONS. THE ONLY OTHER UPDATE FOR THIS MORNING WAS TO RAISE DEW
POINTS AS WE ARE RUNNING A FEW DEGREES HIGHER THAN PREVIOUS
FORECAST INDICATED. OTHERWISE...THE FORECAST IS IN GOOD SHAPE.
UPDATED PRODUCTS HAVE ALREADY BEEN SENT. /19/
&&
.PREV DISCUSSION... /ISSUED 448 AM CDT THU MAY 7 2015/
DISCUSSION...
IR AND RADAR MOSAICS SHOWING A DECAYING MCS ACROSS EASTERN
OKLAHOMA INTO NORTH CENTRAL TEXAS. THE SYSTEM IS DECAYING BECAUSE
LOW LEVEL INFLOW INTO THE SYSTEM IS MUCH WEAKER COMPARED TO A MUCH
STRONGER LOW LEVEL JET JUST TO THE WEST OF THE SYSTEM. THE
TERMINAL FORECAST PACKAGE FOR TODAY/THIS EVENING WILL BE TIED TO A
REMNANT OUTFLOW BOUNDARY PRODUCED BY THIS LARGE CLUSTER OF
THUNDERSTORMS. SHORT TERM PROGS ARE NOT HANDLING THIS SYSTEM VERY
WELL AT ALL...BUT THE HRRR DOES AT LEAST ACKNOWLEDGE THE REMNANT
BOUNDARY WHICH SHOULD SET UP WEST TO EAST ACROSS OUR NORTHERN
ZONES TODAY. THUS...WITH DAYTIME HEATING AND INSTABILITY...THE
BOUNDARY SHOULD SERVE AS A FOCUS FOR SCATTERED CONVECTION WHICH
COULD INFLUENCE AT THE VERY LEAST THE TXK TERMINAL. IF THE
BOUNDARY WAS TO PUSH FURTHER SOUTH TOWARDS THE I-20
CORRIDOR...THEN OUR NE TX TERMINALS WOULD BE IN PLAY FOR AFTERNOON
CONVECTION.
FOR NOW...WILL JUST MAKE MENTION OF VCTS AT THE TXK TERMINAL AND
KEEP ALL OTHER TERMINALS OUT OF THIS MENTION. NOT SAYING OUR OTHER
TERMINALS WILL BE COMPLETELY VOID OF TSRA TODAY BUT CHANCES DO NOT
WARRANT A MENTION ATTM.
MVFR/IFR CEILINGS HAVE BEEN CONFINED TO OUR TYR TERMINAL ONLY AS
OF THIS DISCUSSION EARLY THIS MORNING BUT STILL EXPECTING TO SEE
THIS CLOUD COVER MOVE INTO AT LEAST THE LFK/GGG TERMINALS. THESE
CONDITIONS SHOULD LIFT AND/OR SCATTER OUT BY LATE MORNING/EARLY
AFTERNOON. SHOULD SEE A LITTLE MORE IN THE WAY OF MVFR/IFR
CEILINGS ONCE AGAIN OVERNIGHT TONIGHT INTO EARLY FRIDAY MORNING.
13
PREV DISCUSSION... /ISSUED 436 AM CDT THU MAY 7 2015/
DISCUSSION...
MCS OVER N TX HAS FINALLY PICKED UP SOME FORWARD MOMENTUM OVER
THE LAST COUPLE OF HRS. LATEST RADAR LOOPS INDICATE PORTIONS OF
THE MCS NORTH OF THE RED RIVER HAVE MORE OF A NELY MOVEMENT AND
ARE BEGINNING TO DISSIPATE...SEGMENT NEAR AND SOUTH OF THE RED
RIVER IS MOVING MORE EASTERLY AND IS A BIT MORE ORGANIZED. IR
IMAGERY OVER THE LAST FEW HRS ALSO INDICATE THAT CLOUD TOPS ARE
WARMING WHICH ALSO SUGGESTS AN OVERALL DECREASE IN INTENSITY.
THESE TRENDS ARE EXPECTED TO CONTINUE AS THE COMPLEX APPROACHES.
THE MCS SHOULD REACH PORTIONS OF SE OK/NE TX NORTH OF I-30 BEFORE
DISSIPATING AND/OR MOVING NE OF THE AREA. MOST OF THE MODELS HAVE
NOT HANDLED THIS COMPLEX PARTICULARLY WELL...ALTHOUGH THE HRRR
SEEMS TO HAVE THE BEST SOLUTION COMPARED TO CURRENT CONDITIONS
AND LATEST TRENDS. INCLUDED UPDATED POP/WX GRIDS FOR THE PERIOD
BEFORE 12Z THIS MORNING.
IN REGARDS TO RAIN CHANCES TODAY...THE MODELS ARE PRACTICALLY
WORTHLESS. NONE OF THEM INITIALIZED PARTICULARLY WELL IN THEIR
HANDLING OF THE ONGOING N TX MCS. THE 00Z NAM AND A COUPLE OF HI-
RES MODELS DEVELOP A COMPLEX ACROSS W TX AND SWEEP IT QUICKLY
EASTWARD WITH QUITE A ROBUST LOOKING MCS FROM TYLER TX TO PRESCOTT
AR AT 00Z THIS EVENING. THE BIGGEST PROBLEM WITH THIS FORECAST IS
THAT IT RESULTS FROM TSTMS SUPPOSEDLY ALREADY ONGOING ACROSS W TX
WHERE NOTHING IS ACTUALLY OCCURRING. THE GFS IS ILL-DEFINED WITH
WIDESPREAD QPF EVERYWHERE AND THE ECMWF APPEARS TO BE SUFFERING
SOME CONVECTIVE FEEDBACK ISSUES.
SINCE THE OVERALL SYNOPTIC PATTERN IS LARGELY UNCHANGED FROM
WEDNESDAY...A PERSISTENCE FORECAST WILL ONCE AGAIN BE USED TODAY
AND FRIDAY. CHANCES FOR CONVECTION MAY BE A BIT HIGHER TODAY IF
THE SEGMENT OF THE ONGOING MCS SOUTH OF THE RED RIVER CAN MAINTAIN
ITSELF LONG ENOUGH TO TAKE ADVANTAGE OF DIURNAL HEATING TODAY.
EVEN IF THE MCS DOES DISSIPATE...A RESIDUAL OUTFLOW BOUNDARY COULD
PROVIDE A FOCUS FOR SHWRS/TSTMS THIS AFTERNOON AND EARLY THIS
EVENING. POTENTIAL WILL EXIST ONCE AGAIN FOR CONVECTION THAT
DEVELOPS FARTHER WEST OVER OK/TX TO MOVE INTO THE ARKLATEX EARLY
FRIDAY MORNING...BUT WILL GENERALLY KEEP POPS LESS THAN 30 PERCENT
AT THIS TIME. AFTERNOON HIGH TEMPERATURES WILL CONTINUE TO RUN IN
THE LOW TO MID 80S AREAWIDE.
SATURDAY WILL LIKELY BE VERY SIMILAR TO TODAY AND FRIDAY.
HOWEVER...A LARGE AND STRONG UPPER TROUGH WILL BE MOVING EWD
THROUGH THE FOUR CORNERS REGION BEFORE EJECTING NEWD INTO KS/NE BY
EARLY SUNDAY MORNING. THE INCREASED LARGE SCALE ASCENT SHOULD ALSO
RESULT IN MUCH HIGHER RAIN CHANCES BEGINNING DURING THE DAY
SATURDAY ACROSS THE NW HALF OF THE CWA.
BEST CHANCES FOR WIDESPREAD...AND POSSIBLY LOCALLY HEAVY
RAINFALL...WILL BE LATE SUNDAY THROUGH MONDAY. A COLD FRONT WILL
BEGIN TO APPROACH AND EVENTUALLY MOVE ACROSS THE AREA AS THE AXIS
OF THE UPPER TROUGH SWINGS EAST ACROSS THE SRN PLAINS. SEVERE
WEATHER WILL BE A POSSIBILITY DURING THIS TIME FRAME...DAMAGING
WINDS AND HAIL SHOULD BE THE PRIMARY THREATS. THE SURFACE FRONT
MAY STALL SOMEWHERE JUST SOUTH OF THE CWA BY TUESDAY. MEDIUM
RANGE MODELS SUGGEST THE 850 MB FRONT WILL STALL SOMEWHERE NEAR
I-20. THIS WILL KEEP SHWRS/TSTMS THROUGH IN THE FORECAST THROUGH
THE EXTENDED PERIODS MAINLY SOUTH OF I-30.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 84 69 85 71 / 30 20 30 30
MLU 86 67 87 70 / 20 10 20 10
DEQ 81 68 82 68 / 30 30 30 40
TXK 83 68 83 69 / 30 20 30 30
ELD 85 68 85 69 / 20 20 20 20
TYR 83 69 84 69 / 30 20 30 30
GGG 84 69 85 70 / 30 20 30 30
LFK 86 70 87 71 / 30 20 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
448 AM CDT THU MAY 7 2015
.DISCUSSION...
IR AND RADAR MOSAICS SHOWING A DECAYING MCS ACROSS EASTERN
OKLAHOMA INTO NORTH CENTRAL TEXAS. THE SYSTEM IS DECAYING BECAUSE
LOW LEVEL INFLOW INTO THE SYSTEM IS MUCH WEAKER COMPARED TO A MUCH
STRONGER LOW LEVEL JET JUST TO THE WEST OF THE SYSTEM. THE
TERMINAL FORECAST PACKAGE FOR TODAY/THIS EVENING WILL BE TIED TO A
REMNANT OUTFLOW BOUNDARY PRODUCED BY THIS LARGE CLUSTER OF
THUNDERSTORMS. SHORT TERM PROGS ARE NOT HANDLING THIS SYSTEM VERY
WELL AT ALL...BUT THE HRRR DOES AT LEAST ACKNOWLEDGE THE REMNANT
BOUNDARY WHICH SHOULD SET UP WEST TO EAST ACROSS OUR NORTHERN
ZONES TODAY. THUS...WITH DAYTIME HEATING AND INSTABILITY...THE
BOUNDARY SHOULD SERVE AS A FOCUS FOR SCATTERED CONVECTION WHICH
COULD INFLUENCE AT THE VERY LEAST THE TXK TERMINAL. IF THE
BOUNDARY WAS TO PUSH FURTHER SOUTH TOWARDS THE I-20
CORRIDOR...THEN OUR NE TX TERMINALS WOULD BE IN PLAY FOR AFTERNOON
CONVECTION.
FOR NOW...WILL JUST MAKE MENTION OF VCTS AT THE TXK TERMINAL AND
KEEP ALL OTHER TERMINALS OUT OF THIS MENTION. NOT SAYING OUR OTHER
TERMINALS WILL BE COMPLETELY VOID OF TSRA TODAY BUT CHANCES DO NOT
WARRANT A MENTION ATTM.
MVFR/IFR CEILINGS HAVE BEEN CONFINED TO OUR TYR TERMINAL ONLY AS
OF THIS DISCUSSION EARLY THIS MORNING BUT STILL EXPECTING TO SEE
THIS CLOUD COVER MOVE INTO AT LEAST THE LFK/GGG TERMINALS. THESE
CONDITIONS SHOULD LIFT AND/OR SCATTER OUT BY LATE MORNING/EARLY
AFTERNOON. SHOULD SEE A LITTLE MORE IN THE WAY OF MVFR/IFR
CEILINGS ONCE AGAIN OVERNIGHT TONIGHT INTO EARLY FRIDAY MORNING.
13
&&
.PREV DISCUSSION... /ISSUED 436 AM CDT THU MAY 7 2015/
DISCUSSION...
MCS OVER N TX HAS FINALLY PICKED UP SOME FORWARD MOMENTUM OVER
THE LAST COUPLE OF HRS. LATEST RADAR LOOPS INDICATE PORTIONS OF
THE MCS NORTH OF THE RED RIVER HAVE MORE OF A NELY MOVEMENT AND
ARE BEGINNING TO DISSIPATE...SEGMENT NEAR AND SOUTH OF THE RED
RIVER IS MOVING MORE EASTERLY AND IS A BIT MORE ORGANIZED. IR
IMAGERY OVER THE LAST FEW HRS ALSO INDICATE THAT CLOUD TOPS ARE
WARMING WHICH ALSO SUGGESTS AN OVERALL DECREASE IN INTENSITY.
THESE TRENDS ARE EXPECTED TO CONTINUE AS THE COMPLEX APPROACHES.
THE MCS SHOULD REACH PORTIONS OF SE OK/NE TX NORTH OF I-30 BEFORE
DISSIPATING AND/OR MOVING NE OF THE AREA. MOST OF THE MODELS HAVE
NOT HANDLED THIS COMPLEX PARTICULARLY WELL...ALTHOUGH THE HRRR
SEEMS TO HAVE THE BEST SOLUTION COMPARED TO CURRENT CONDITIONS
AND LATEST TRENDS. INCLUDED UPDATED POP/WX GRIDS FOR THE PERIOD
BEFORE 12Z THIS MORNING.
IN REGARDS TO RAIN CHANCES TODAY...THE MODELS ARE PRACTICALLY
WORTHLESS. NONE OF THEM INITIALIZED PARTICULARLY WELL IN THEIR
HANDLING OF THE ONGOING N TX MCS. THE 00Z NAM AND A COUPLE OF HI-
RES MODELS DEVELOP A COMPLEX ACROSS W TX AND SWEEP IT QUICKLY
EASTWARD WITH QUITE A ROBUST LOOKING MCS FROM TYLER TX TO PRESCOTT
AR AT 00Z THIS EVENING. THE BIGGEST PROBLEM WITH THIS FORECAST IS
THAT IT RESULTS FROM TSTMS SUPPOSEDLY ALREADY ONGOING ACROSS W TX
WHERE NOTHING IS ACTUALLY OCCURRING. THE GFS IS ILL-DEFINED WITH
WIDESPREAD QPF EVERYWHERE AND THE ECMWF APPEARS TO BE SUFFERING
SOME CONVECTIVE FEEDBACK ISSUES.
SINCE THE OVERALL SYNOPTIC PATTERN IS LARGELY UNCHANGED FROM
WEDNESDAY...A PERSISTENCE FORECAST WILL ONCE AGAIN BE USED TODAY
AND FRIDAY. CHANCES FOR CONVECTION MAY BE A BIT HIGHER TODAY IF
THE SEGMENT OF THE ONGOING MCS SOUTH OF THE RED RIVER CAN MAINTAIN
ITSELF LONG ENOUGH TO TAKE ADVANTAGE OF DIURNAL HEATING TODAY.
EVEN IF THE MCS DOES DISSIPATE...A RESIDUAL OUTFLOW BOUNDARY COULD
PROVIDE A FOCUS FOR SHWRS/TSTMS THIS AFTERNOON AND EARLY THIS
EVENING. POTENTIAL WILL EXIST ONCE AGAIN FOR CONVECTION THAT
DEVELOPS FARTHER WEST OVER OK/TX TO MOVE INTO THE ARKLATEX EARLY
FRIDAY MORNING...BUT WILL GENERALLY KEEP POPS LESS THAN 30 PERCENT
AT THIS TIME. AFTERNOON HIGH TEMPERATURES WILL CONTINUE TO RUN IN
THE LOW TO MID 80S AREAWIDE.
SATURDAY WILL LIKELY BE VERY SIMILAR TO TODAY AND FRIDAY.
HOWEVER...A LARGE AND STRONG UPPER TROUGH WILL BE MOVING EWD
THROUGH THE FOUR CORNERS REGION BEFORE EJECTING NEWD INTO KS/NE BY
EARLY SUNDAY MORNING. THE INCREASED LARGE SCALE ASCENT SHOULD ALSO
RESULT IN MUCH HIGHER RAIN CHANCES BEGINNING DURING THE DAY
SATURDAY ACROSS THE NW HALF OF THE CWA.
BEST CHANCES FOR WIDESPREAD...AND POSSIBLY LOCALLY HEAVY
RAINFALL...WILL BE LATE SUNDAY THROUGH MONDAY. A COLD FRONT WILL
BEGIN TO APPROACH AND EVENTUALLY MOVE ACROSS THE AREA AS THE AXIS
OF THE UPPER TROUGH SWINGS EAST ACROSS THE SRN PLAINS. SEVERE
WEATHER WILL BE A POSSIBILITY DURING THIS TIME FRAME...DAMAGING
WINDS AND HAIL SHOULD BE THE PRIMARY THREATS. THE SURFACE FRONT
MAY STALL SOMEWHERE JUST SOUTH OF THE CWA BY TUESDAY. MEDIUM
RANGE MODELS SUGGEST THE 850 MB FRONT WILL STALL SOMEWHERE NEAR
I-20. THIS WILL KEEP SHWRS/TSTMS THROUGH IN THE FORECAST THROUGH
THE EXTENDED PERIODS MAINLY SOUTH OF I-30.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 84 69 85 71 / 30 20 30 30
MLU 86 67 87 70 / 20 10 20 10
DEQ 81 68 82 68 / 30 30 30 40
TXK 83 68 83 69 / 30 20 30 30
ELD 85 68 85 69 / 20 20 20 20
TYR 83 69 84 69 / 30 20 30 30
GGG 84 69 85 70 / 30 20 30 30
LFK 86 70 87 71 / 30 20 30 30
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
09/13
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
722 PM EDT FRI MAY 8 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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 722 PM EDT FRI MAY 8 2015
AT KIWD AND KCMX...VFR CONDITIONS WILL CONTINUE AS DRY AIR MOVES
INTO THE AREA.
AT KSAW...VFR CONDITIONS WILL CONTINUE UNTIL AN AREA OF LOW LEVEL
MOISTURE MOVES INTO THE AREA WITH N-NNE WINDS LATE TONIGHT INTO
SAT...RESULTING IN REDUCED MVFR CIGS.
&&
.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
946 PM CDT FRI MAY 8 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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 707 PM CDT FRI MAY 8 2015
MVFR CEILINGS EXPECTED TO PERSIST AT KINL UNTIL 08Z THIS EVENING.
ALL OTHER TERMINALS ARE EXPECTED TO SEE VFR CONDITIONS THROUGH THE
FORECAST PERIOD. HIGH PRESSURE WILL WORK ITS WAY INTO THE NORTHERN
PLAINS FROM CENTRAL MANITOBA TONIGHT AND TOMORROW. HOWEVER...THERE
IS ENOUGH MOISTURE IN THE LOWER LEVELS FOR CLOUDS TO DEVELOP
BETWEEN 3500-4000 FT BETWEEN 08Z AND 18Z. KDLH WILL SEE EASTERLY
FLOW DEVELOP TOMORROW MORNING. LATEST NAM/RAP SUGGEST MVFR AND IFR
CEILINGS POSSIBLE BETWEEN 12Z-16Z AT KDLH. NOT OVERLY CONFIDENT AT
THIS POINT THAT THIS WILL OCCUR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 55 39 42 / 0 10 10 70
INL 36 58 37 52 / 0 10 10 40
BRD 40 64 43 48 / 0 0 20 80
HYR 41 64 41 54 / 0 0 10 70
ASX 41 53 36 48 / 0 10 10 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...GSF/WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
707 PM CDT FRI MAY 8 2015
.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 KTS...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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 707 PM CDT FRI MAY 8 2015
MVFR CEILINGS EXPECTED TO PERSIST AT KINL UNTIL 08Z THIS EVENING.
ALL OTHER TERMINALS ARE EXPECTED TO SEE VFR CONDITIONS THROUGH THE
FORECAST PERIOD. HIGH PRESSURE WILL WORK ITS WAY INTO THE NORTHERN
PLAINS FROM CENTRAL MANITOBA TONIGHT AND TOMORROW. HOWEVER...THERE
IS ENOUGH MOISTURE IN THE LOWER LEVELS FOR CLOUDS TO DEVELOP
BETWEEN 3500-4000FT BETWEEN 08Z AND 18Z. KDLH WILL SEE EASTERLY
FLOW DEVELOP TOMORROW MORNING. LATEST NAM/RAP SUGGEST MVFR AND IFR
CEILINGS POSSIBLE BETWEEN 12Z-16Z AT KDLH. NOT OVERLY CONFIDENT AT
THIS POINT THAT THIS WILL OCCUR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 41 55 39 42 / 0 10 10 70
INL 36 58 37 52 / 0 10 10 40
BRD 40 64 43 48 / 0 0 20 80
HYR 41 64 41 54 / 0 0 10 70
ASX 41 53 36 48 / 0 10 10 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...CLC
AVIATION...GSF/WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1232 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1232 PM CDT THU MAY 7 2015
UPDATED FOR THE NEW 18Z AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 1014 AM CDT THU MAY 7 2015
WE HAVE MADE SOME ADJUSTMENTS THIS MORNING TO LOWER POPS...MAINLY
FAR EAST WHERE NO RAIN HAS FALLEN YET. OVERALL...AREA RADARS SHOW
SCATTERED SHOWERS WITH HIGHEST COVERAGE OVER OUR NORTHWEST ZONES
AS OF 15Z. SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON
BUT COVERAGE MAY NOT BE WIDESPREAD. WE LEFT POPS HIGH THOUGH AS WE
DO EXPECT TO SEE SHOWERS AND STORMS MOVE THROUGH...BUT THERE WILL
BE BREAKS AT TIMES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1232 PM CDT THU MAY 7 2015
THE WIDESPREAD MVFR CIGS ACROSS NE MINNESOTA AND NW WISCONSIN
EARLY THIS AFTERNOON WILL LIKELY CONTINUE UNTIL LATE FRIDAY
MORNING. SOUTHERLY FLOW AHEAD OF A LOW IN NW MINNESOTA SHOULD
CONTINUE TO CAUSE WIDESPREAD BKN/OVC CIGS BETWEEN 2 AND 4 KFT
AGL. THERE WILL BE PERIODS OF -SHRA AND -TSRA THROUGH THIS
EVENING. THE MAIN THREAT FOR -TSRA WILL BE LATER THIS AFTERNOON
AND THIS EVENING WHEN THE LOW AND ITS COLD FRONT MOVE THROUGH THE
REGION...FROM WEST TO EAST. NORTHWEST WINDS OF 10 TO 20 KNOTS WILL
DEVELOP IN THE WAKE OF THE COLD FRONT LATER TODAY AND TONIGHT.
THERE COULD BE BRIEF PERIODS OF IFR CIGS/VSBYS LATER THIS
AFTERNOON AND THIS EVENING DURING THE STORMS AND DUE TO MIST
FORMING IN THE WAKE OF HEAVIER SHOWERS. IFR CIGS COULD ALSO BE
POSSIBLE AT TIMES TONIGHT...BUT CONFIDENCE RELATIVELY LOW. THINK
THE NW WINDS WILL HELP LIFT THE CIGS TO KEEP CIGS PRIMARILY IN
MVFR.
THERE SHOULD BE LIFTING AND SCATTERING LATE FRIDAY MORNING AND
FRIDAY AFTERNOON. MOST TERMINALS SHOULD RETURN TO VFR BY FRIDAY
AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 69 47 58 40 / 80 80 20 0
INL 68 42 53 34 / 80 70 20 0
BRD 70 47 57 39 / 80 60 10 0
HYR 76 53 63 41 / 70 80 20 0
ASX 79 52 62 37 / 70 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
1016 AM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1014 AM CDT THU MAY 7 2015
WE HAVE MADE SOME ADJUSTMENTS THIS MORNING TO LOWER POPS...MAINLY
FAR EAST WHERE NO RAIN HAS FALLEN YET. OVERALL...AREA RADARS SHOW
SCATTERED SHOWERS WITH HIGHEST COVERAGE OVER OUR NORTHWEST ZONES
AS OF 15Z. SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON
BUT COVERAGE MAY NOT BE WIDESPREAD. WE LEFT POPS HIGH THOUGH AS WE
DO EXPECT TO SEE SHOWERS AND STORMS MOVE THROUGH...BUT THERE WILL
BE BREAKS AT TIMES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU MAY 7 2015
RAIN SHOWERS WILL CONTINUE TO MOVE NWD THROUGH THE REGION ALONG
AND AHEAD OF A SLOW MOVING N-S ORIENTED COLD FRONT. WILL LIKELY
SEE THE INITIAL BAND OF SHOWERS MOVE THROUGH THIS MORNING WITH
POSSIBLY A BRIEF BREAK IN THE LATE MORNING AND EARLY AFTERNOON.
SLIGHT DESTABILIZATION IN THE AFTERNOON WILL LEAD TO POSSIBLY A
ROUND OF MORE INTENSE RAIN SHOWERS AND SCATTERED THUNDERSTORMS.
THE SHOWERS AND STORMS COULD LINGER INTO THE EVENING BEFORE
TAPERING OFF AND/OR BECOMING MORE LIGHT AND STRATIFORM INTO THE
LATE EVENING AND OVERNIGHT. THE FRONT WILL PUSH THROUGH LATE
TONIGHT AND FRIDAY MORNING WITH LOW CLOUDS AND RAIN LINGERING.
SHOULD SEE IMPROVEMENT IN CONDITIONS FROM NW TO SE FRI MORNING.
EXPECT GUSTY SOUTH WINDS AHEAD OF THE FRONT TODAY...WITH A SHIFT
TO LIGHT AND VARIABLE NEAR THE FRONT AND VEERING WINDS TO THE NW
BEHIND THE FRONT TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 69 47 58 40 / 80 80 20 0
INL 68 42 53 34 / 80 70 20 0
BRD 70 47 57 39 / 80 70 10 0
HYR 76 53 63 41 / 80 80 20 0
ASX 79 52 62 37 / 70 80 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...MELDE
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
638 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 637 AM CDT THU MAY 7 2015
RAIN SHOWERS WILL CONTINUE TO MOVE NWD THROUGH THE REGION ALONG
AND AHEAD OF A SLOW MOVING N-S ORIENTED COLD FRONT. WILL LIKELY
SEE THE INITIAL BAND OF SHOWERS MOVE THROUGH THIS MORNING WITH
POSSIBLY A BRIEF BREAK IN THE LATE MORNING AND EARLY AFTERNOON.
SLIGHT DESTABILIZATION IN THE AFTERNOON WILL LEAD TO POSSIBLY A
ROUND OF MORE INTENSE RAIN SHOWERS AND SCATTERED THUNDERSTORMS.
THE SHOWERS AND STORMS COULD LINGER INTO THE EVENING BEFORE
TAPERING OFF AND/OR BECOMING MORE LIGHT AND STRATIFORM INTO THE
LATE EVENING AND OVERNIGHT. THE FRONT WILL PUSH THROUGH LATE
TONIGHT AND FRIDAY MORNING WITH LOW CLOUDS AND RAIN LINGERING.
SHOULD SEE IMPROVEMENT IN CONDITIONS FROM NW TO SE FRI MORNING.
EXPECT GUSTY SOUTH WINDS AHEAD OF THE FRONT TODAY...WITH A SHIFT
TO LIGHT AND VARIABLE NEAR THE FRONT AND VEERING WINDS TO THE NW
BEHIND THE FRONT TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 70 47 58 40 / 80 80 20 0
INL 70 42 53 34 / 80 60 20 0
BRD 72 47 57 39 / 80 70 10 0
HYR 76 53 63 41 / 80 80 20 0
ASX 79 52 62 37 / 70 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
549 AM CDT THU MAY 7 2015
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT THU MAY 7 2015
THE SHORT TERM CONCERNS ARE TIMING AND EXTENT OF CONVECTION AND
TEMPERATURES.
WATER VAPOR IMAGERY IS SHOWING SHORT WAVE TROUGH EXTENSION ACROSS
SOUTHEAST SOUTH DAKOTA INTO IOWA THIS MORNING. AREA OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THIS FEATURE...MOSTLY CONCENTRATED
ACROSS NORTHWEST IOWA/SOUTHWEST MINNESOTA. SPC MESOSCALE ANALYSIS
SHOWING DECENT 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...WITH
MORE SHOWERS AND ISOLATED THUNDER DEVELOPING OUT ACROSS CENTRAL MN.
THIS SHOULD CONTINUE TO BE THE TREND AS THIS TROUGH LIFTS
NORTHEAST...AND THE MOISTURE TRANSPORT MAXIMIZES OVER MN. EXPECT AT
LEAST LIKELY POPS AS THIS LIFTS NORTHWEST. THE LATEST HRRR FORECAST
REFLECTIVITY SHOWS THIS TREND AS WELL.
CLOUDS ARE EXPECTED TO REMAIN...THOUGH SOME EROSION MAY OCCUR LATE
THIS MORNING BEFORE CONVECTION REFIRES...OR ENHANCES ONCE AGAIN.
DAY1 OUTLOOK HAS EXPANDED THE MARGINAL SEVERE WEATHER RISK OUT AHEAD
OF THE COLD FRONT. THIS WILL BE FOR THE AFTERNOON/EARLY EVENING
EAST OF THE COLD FRONT. STEEP LAPSE RATES INDICTED AND DEPENDING
HOW MUCH HEATING TAKES PLACE...MODEL FORECAST SURFACE BASED CAPE
INCREASING TO 1500 J/KG. BULK SHEAR IS FORECAST TO RANGE 35-40KTS
ALONG AND EAST OF THE FRONT...WHICH WOULD BE ENOUGH FOR THE
POSSIBILITY OF HAIL AND STRONG WINDS WITH THE STRONGER CONVECTION.
THE MODELED UPDRAFT HELICITY WAS INDICATING THE MAIN THREAT OVER
WEST CENTRAL WISCONSIN...WITH WHAT APPEARS TO BE A LEADING SURFACE
TROUGH. WILL HAVE TO MONITOR CLOUD TRENDS AND SEE IF INDEED
INSTABILITY WILL INCREASE ENOUGH TO GENERATE A SMALL SEVERE WEATHER
RISK OVER THE EASTERN CWA.
THE FRONT MOVES INTO WESTERN WISCONSIN THIS EVENING AND SHOULD TAKE
THE BULK OF THE SHOWERS WITH IT. THERE IS SOME THREAT OF MID LEVEL
SHRA DEVELOPING BEHIND THE COLD FRONT INTO CENTRAL MN LATER TONIGHT.
THE MODELS WERE INDICATING SOME STRONGER MID LEVEL FGEN. BUT IT
REMAINS TO BE SEEN IF THERE WILL BE ENOUGH MOISTURE TO CONTINUE THE
SHOWER THREAT. STILL MAINTAINED THE SMALL CHANCE POPS AFTER 06Z
FRI FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU MAY 7 2015
BY FRIDAY MORNING...THE AFOREMENTIONED COLD FRONT AND SURFACE LOW
RESPONSIBLE FOR THE RAIN IN THE SHORT TERM WILL BE EAST OF THE
FORECAST AREA. HIGH PRESSURE WILL BUILD IN ACROSS THE NORTHERN
HIGH PLAINS ON FRIDAY AND INTO THE UPPER MISSISSIPPI RIVER VALLEY
ON SATURDAY. THE POST FRONTAL AIR MASS ON FRIDAY WILL BE QUITE
COOL WITH TEMPERATURES IN CENTRAL/NORTHERN MN LIKELY REMAINING IN
THE 50S DURING THE AFTERNOON. WE MIGHT EVEN BE A LITTLE TOO WARM
WITH FRIDAY`S TEMPERATURES...ESPECAILLY GIVEN THE DECENT CHANCE
FOR A BROKEN TO OVERCAST DECK OF MID CLOUDS. THE WEATHER SHOULD
REMAIN DRY ON FRIDAY. ON SATURDAY...A WEST COAST TROUGH WILL EJECT
EAST OUT OF CALIFORNIA AND PASS OVER THE ROCKIES BEFORE SLOWLY
MAKING ITS TRACK ACROSS THE REGION SUN-TUE. A SURFACE LOW IS
FORECAST TO TRACK FROM THE CENTRAL PLAINS...ACROSS IA...AND
EVENTUALLY REACHING EASTERN LAKE SUPERIOR BY TUESDAY. THAT PUTS
MN/WI IN A PRETTY GOOD SPOT FOR WIDESPREAD RAIN SUNDAY INTO
MONDAY. THE 06.18Z AND 07.00Z RUNS OF THE GFS DEPICT SIMILIAR
SOLUTIONS...A CHANGE FROM THE FEW RUNS BEFORE THESE LAST TWO WHICH
HAD A LOT OF RUN-TO-RUN VARIABILITY IN HOW IT HANDLED THE
PROGRESSION OF THIS SURFACE LOW EARLY NEXT WEEK. THE GFS IS
HEAVIER WITH THE QPF WHEN COMPARED TO THE ECMWF...BECAUSE IT IS
ALSO SLOWER...DEEPER...AND FARTHER SOUTH THAN THE ECMWF. THE ECMWF
HAS ALSO HAD A COUPLE RUNS NOW WITH BETTER CONSISTENCY. WE TRENDED
THE TEMPS A BIT COOLER MON-WED...WITH THE FREEZING LEVEL JUST A
COUPLE THOUSAND FEET OFF THE GROUND TUE-WED. TEMPERATURES REALLY
DO NOT START TO MODIFY UNTIL AT LEAST THURSDAY. SO...MN/WI IS IN
FOR A COOL WEEK AFTER THE RAIN MOVES TUE-TUE NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 545 AM CDT THU MAY 7 2015
BAND OF SHOWERS/ISOLATED THUNDER LIFTING NORTH AHEAD OF THE
DAKOTAS TROUGH. EXPECT THIS TO GRADUALLY WEAKEN AND LIFT OFF TO
THE NORTH. OTHERWISE...REDEVELOPMENT LIKELY BY 18Z...MAINLY SHRA
WITH EMBEDDED THUNDER...ESPECIALLY ALONG EASTERN TROUGH AXIS AND
REAL COLD FRONT PUSHING IN FROM THE NORTHWEST. ACTIVITY SHOULD
WANE TO THE WEST THROUGH 06Z AND JUST AFTER 06Z TO THE FAR EAST.
EXPECT MVFR CONDITIONS WITH THE THUNDER AND THEN WITH BAND OF
CLOUDS DEVELOPING BEHIND THE COLD FRONT. THAT SHOULD PUSH INTO
KAXN BY 00Z AND THEN MOVE OUT BY 07Z. SOUTHEAST TO SOUTH WINDS ARE
GUSTY INTO THE DAY...AND WILL BECOME NORTHWEST WITH FROPA.
KMSP...
BAND OF -SHRA MOVING THROUGH THROUGH ABOUT 14Z...AND REDEVELOPMENTTHIS
AFTERNOON. MENTIONED TSRA IN THE 20-24Z PERIOD FOR NOW. FROPA MOVES
IN AROUND 06Z WITH A BAND OF MVFR CIGS EXPECTED THROUGH AT LEAST
15Z FRI. SOME QUESTION AS TO HOW LOW TO GO IN CIGS. RIGHT NOW AM
CONFIDENT ENOUGH TO MENTION 1500 FT AFTER 10Z.
/OUTLOOK FOR KMSP/
FRI AFTERNOON/NIGHT...VFR. WINDS NW 10 KTS.
SAT...VFR. WINDS NE 10 KTS.
SUN...MVFR LIKELY WITH IFR POSSIBLE IN SHWRS/TSTMS. WINDS NE
10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...CLF
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS DULUTH MN
356 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
AT 345 AM...WE SAW ONE AREA OF SHOWERS EXITING THE INTERNATIONAL
BORDER REGION...WHILE A NEW AREA OF SHOWERS AND POSSIBLE STORMS
WAS MOVING INTO THE SOUTHERN CWA. AN AREA OF PARTIAL CLEARING HAD
DEVELOPED IN BETWEEN THOSE TWO AREAS OF PRECIPITATION.
TEMPERATURES RANGED FROM THE 40S NEAR LAKE SUPERIOR TO THE LOWER
60S IN THE SOUTHERN PORTION OF THE CWA.
THE FOCUS FOR THE PERIOD FROM TODAY THROUGH FRIDAY...AND ESPECIALLY
FOR TODAY...IS TRYING TO RESOLVE THE OVERALL PRECIPITATION POTENTIAL
AND AMOUNTS. AN ANALYSIS OF THE HRRR/RAP/WRF AND THE NAM/GFS/ECMWF
INDICATED NONE OF THE MODELS HAD A GOOD HANDLE ON THE CURRENT
PRECIPITATION AREA...WITH MOST OF THE MODELS TOO SLOW WITH THE
CURRENT SHOWERS MOVING INTO THE SOUTHERN CWA. OVERALL...THINK THE
MODELS DO CATCH UP AND THE TREND FOR INCREASING PRECIPITATION
TODAY SOUNDS LIKE A REASONABLE SCENARIO. WILL GENERALLY HAVE HIGH
POPS ACROSS THE CWA TODAY AND TONIGHT...WITH CHANCES INCREASING
THROUGHOUT THE MORNING TODAY. HIGH RESOLUTION MODELS SUCH AS THE
4KM NMM WRF AND THE HRRR INDICATE THE MODE OF PRECIPITATION SHOULD
BECOME MORE CELLULAR DURING THE DAY. SPC HAS A PORTION OF OUR AREA
IN THE MARGINAL SEVERE WEATHER THREAT AREA...AND THAT SEEMS
REASONABLE GIVEN THE BETTER CHANCE FOR SEEING SOME DAYTIME HEATING
AND PARTIAL SUNSHINE IN THE SOUTHERN PORTION OF THE CWA.
PRECIPITABLE WATER VALUES THIS MORNING ARE GENERALLY IN THE 1.2
INCH RANGE. A FORMIDABLE LLJ OF UP TO 50 KT WAS EVIDENT THROUGHOUT
THE PLAINS AND UPPER MIDWEST.
TODAY...WILL GO WITH FAIRLY HIGH POPS. PRECIPITATION WILL COME IN
WAVES AND INCREASE THROUGHOUT THE DAY. HIGHS SHOULD GENERALLY BE
IN THE 70S...ALTHOUGH SOME 60S ARE POSSIBLE IN SPOTS...WITH 40S
AND 50S NEAR THE LAKE. COULD BE SOME STRONG THUNDERSTORMS DURING
THE LATTER PORTION OF THE DAY...AND POSSIBLY AN ISOLATED SEVERE
THUNDERSTORM ACROSS THE SOUTHEAST HALF OF THE CWA.
TONIGHT...SHOWERS AND THUNDERSTORMS WILL BE LIKELY. A FEW STRONG
STORMS WILL AGAIN BE POSSIBLE DURING THE EVENING...ESPECIALLY
ACROSS THE SOUTHEASTERN PORTION OF THE CWA. BY 06Z FRIDAY...THE
COLD FRONT SHOULD REACH THE DULUTH AREA...AND IT SHOULD JUST ABOUT
CLEAR THE SOUTHEAST CWA BY 12Z FRIDAY. WINDS WILL SWITCH TO THE
NORTHWEST BEHIND THE FRONT.
FRIDAY...THE SHOWERS AND STORMS WILL GRADUALLY DIMINISH FROM THE
WEST. ONLY A FEW SHOWERS WILL LINGER FAR EAST INTO THE AFTERNOON.
DRIER AIR WILL PUSH IN FROM THE NORTHWEST...AS DRIER AND COOLER
AIR SPREADS INTO THE AREA FROM CANADIAN HIGH PRESSURE. HIGHS WILL
BE IN THE 50S FOR MOST OF NE MN...WITH SOME 60S IN WI.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU MAY 7 2015
HIGH PRESSURE AT THE SURFACE WILL BE BUILDING IN ACROSS SRN MANITOBA
AND WRN ONTARIO FRIDAY NIGHT AND SATURDAY...AND INTO LAKE SUPERIOR
SAT NIGHT. AS THE HIGH SHIFTS SLIGHTLY TO THE EAST THE NEXT
SIGNIFICANT LOW PRESSURE SYSTEM WILL MOVE FROM THE SRN PLAINS INTO
THE UPPER MIDWEST BY LATE SUNDAY NIGHT/MON MORNING. THE COMBINATION
OF THE SFC HIGH AND APPROACHING LOW TO THE SOUTH WILL INDUCE A
PERSISTENT E/NE WIND OFF LAKE SUPERIOR FRI NIGHT THROUGH MONDAY
NIGHT. THE APPROACHING SYSTEM WILL ONCE AGAIN DRAW UP A LARGE SUPPLY
OF MOISTURE FROM THE SOUTH AND DEPOSIT IT IN THE FORM OF WIDESPREAD
RAIN SHOWERS ACROSS THE NORTHLAND THROUGH THE DAY SUNDAY AND
CONTINUING INTO MONDAY AS THE SYSTEM WRAPS UP MOVING INTO THE GREAT
LAKES. THIS SYSTEM WILL BE FAIRLY DYNAMIC WITH A STRONG WARM FRONT
OUT AHEAD OF THE LOW...WHICH COULD BE CAPABLE OF PRODUCING SCATTERED
THUNDERSTORMS WITH THE SHOWERS DURING THE DAY SUNDAY. THE SYSTEM
THEN BEGINS TO LOOK MORE LIKE A WINTER-TYPE LOW AS AN AREA OF COLDER
AIR FILLS IN ON THE BACK SIDE...AND A TROWAL-LOOKING FEATURE
DEVELOPS TO THE EAST WITH AN AREA OF ROBUST STRATIFORM RAIN FORMING
IN THE DEFORMATION ZONE ACROSS NRN MN. THE RAIN SHOULD LINGER INTO
LATE MONDAY AND EARLY TUESDAY AS THE COLD AIR CONTINUES TO DROP IN
ACROSS THE UPPER MIDWEST BEHIND THE DEPARTING SYSTEM. THE AMT AND
DEPTH OF THE COLD AIR COULD ACTUALLY CHANGE OVER TO RAIN OR MIX WITH
SNOW AT TIMES TUESDAY MORNING. NO ACCUMULATION IS EXPECTED AT THIS
TIME. HIGH PRESSURE WILL BUILD IN BEHIND THE SYSTEM INTO THE MIDDLE
OF THE WEEK...BUT ONLY FOR A BRIEF PERIOD AS THE NEXT WEAK INVERTED
TROUGH SLIDES IN FROM THE WEST WITH ADDITIONAL CHANCES FOR LIGHT
RAIN.
TEMPERATURES WILL BE NOTICEABLY COOLER THROUGH MUCH OF THE EXTENDED
PERIOD...ESPECIALLY AROUND THE TWIN PORTS AREA WITH A PERSISTENT
E/NE WIND OFF LAKE SUPERIOR. WHILE AREAS INLAND COULD SEE UPPER 50S
AND 60S AT TIMES...LOCATIONS CLOSER TO THE LAKE WILL ONLY SEE 40S
AND LOWER 50S DURING THE DAY. THE PRESENCE OF A LAKE BREEZE WILL
MAKE IT SEEM EVEN COLDER. OVERNIGHT LOWS WILL GENERALLY BOTTOM OUT
IN THE 30S AND LOWER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1245 AM CDT THU MAY 7 2015
MAINLY VFR-MVFR CEILINGS AND VISIBILITIES ACROSS NORTHERN
MINNESOTA AND NORTHWEST WISCONSIN AS OF 05Z. SOME ISOLATED SHOWERS
EXPECTED THE NEXT FEW HOURS...BRINGING MVFR CEILINGS AND
VISIBILITIES. WITH THE MOISTURE CONTINUING TO PUMP UP INTO THE
AREA...EXPECT SOME LOWERING OF CLOUD BASES...AND TERMINALS SHOULD
SEE DEVELOPMENT OF MVFR CEILINGS THE NEXT FEW HOURS. A STRONG LOW
LEVEL JET OF 35-45KTS HAS PRODUCED LLWS OVER THE TERMINALS WHICH
SHOULD CONTINUE THROUGH APPROXIMATELY 12Z WHEN SURFACE WINDS
INCREASE. THE NEXT WAVE OF SHOWERS TO PUSH THROUGH THE TERMINALS
BEGINNING AROUND 09Z...BRINGING IFR-MVFR CEILINGS AND VISIBILITIES
FOR A FEW HOURS...BEFORE ONCE AGAIN RETURNING TO VFR. ANOTHER WAVE
OF SHOWERS WITH SOME THUNDERSTORMS WILL PUSH THROUGH THE TERMINALS
BEGINNING AROUND 15Z...AND MAY BRING A PERIOD OF THUNDER WITH MVFR
CEILINGS AND IFR VISIBILITIES WITH STRONGER CELLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 70 47 58 40 / 80 80 20 0
INL 70 42 53 34 / 80 60 20 0
BRD 72 47 57 39 / 80 70 10 0
HYR 76 53 63 41 / 80 80 20 0
ASX 79 52 62 37 / 70 70 30 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM...BJT
AVIATION...LE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
350 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CDT THU MAY 7 2015
THE SHORT TERM CONCERNS ARE TIMING AND EXTENT OF CONVECTION AND
TEMPERATURES.
WATER VAPOR IMAGERY IS SHOWING SHORT WAVE TROUGH EXTENSION ACROSS
SOUTHEAST SOUTH DAKOTA INTO IOWA THIS MORNING. AREA OF SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH THIS FEATURE...MOSTLY CONCENTRATED
ACROSS NORTHWEST IOWA/SOUTHWEST MINNESOTA. SPC MESOSCALE ANALYSIS
SHOWING DECENT 850MB MOISTURE TRANSPORT AHEAD OF THE TROUGH...WITH
MORE SHOWERS AND ISOLATED THUNDER DEVELOPING OUT ACROSS CENTRAL MN.
THIS SHOULD CONTINUE TO BE THE TREND AS THIS TROUGH LIFTS
NORTHEAST...AND THE MOISTURE TRANSPORT MAXIMIZES OVER MN. EXPECT AT
LEAST LIKELY POPS AS THIS LIFTS NORTHWEST. THE LATEST HRRR FORECAST
REFLECTIVITY SHOWS THIS TREND AS WELL.
CLOUDS ARE EXPECTED TO REMAIN...THOUGH SOME EROSION MAY OCCUR LATE
THIS MORNING BEFORE CONVECTION REFIRES...OR ENHANCES ONCE AGAIN.
DAY1 OUTLOOK HAS EXPANDED THE MARGINAL SEVERE WEATHER RISK OUT AHEAD
OF THE COLD FRONT. THIS WILL BE FOR THE AFTERNOON/EARLY EVENING
EAST OF THE COLD FRONT. STEEP LAPSE RATES INDICTED AND DEPENDING
HOW MUCH HEATING TAKES PLACE...MODEL FORECAST SURFACE BASED CAPE
INCREASING TO 1500 J/KG. BULK SHEAR IS FORECAST TO RANGE 35-40KTS
ALONG AND EAST OF THE FRONT...WHICH WOULD BE ENOUGH FOR THE
POSSIBILITY OF HAIL AND STRONG WINDS WITH THE STRONGER CONVECTION.
THE MODELED UPDRAFT HELICITY WAS INDICATING THE MAIN THREAT OVER
WEST CENTRAL WISCONSIN...WITH WHAT APPEARS TO BE A LEADING SURFACE
TROUGH. WILL HAVE TO MONITOR CLOUD TRENDS AND SEE IF INDEED
INSTABILITY WILL INCREASE ENOUGH TO GENERATE A SMALL SEVERE WEATHER
RISK OVER THE EASTERN CWA.
THE FRONT MOVES INTO WESTERN WISCONSIN THIS EVENING AND SHOULD TAKE
THE BULK OF THE SHOWERS WITH IT. THERE IS SOME THREAT OF MID LEVEL
SHRA DEVELOPING BEHIND THE COLD FRONT INTO CENTRAL MN LATER TONIGHT.
THE MODELS WERE INDICATING SOME STRONGER MID LEVEL FGEN. BUT IT
REMAINS TO BE SEEN IF THERE WILL BE ENOUGH MOISTURE TO CONTINUE THE
SHOWER THREAT. STILL MAINTAINED THE SMALL CHANCE POPS AFTER 06Z
FRI FOR NOW.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 350 AM CDT THU MAY 7 2015
BY FRIDAY MORNING...THE AFOREMENTIONED COLD FRONT AND SURFACE LOW
RESPONSIBLE FOR THE RAIN IN THE SHORT TERM WILL BE EAST OF THE
FORECAST AREA. HIGH PRESSURE WILL BUILD IN ACROSS THE NORTHERN
HIGH PLAINS ON FRIDAY AND INTO THE UPPER MISSISSIPPI RIVER VALLEY
ON SATURDAY. THE POST FRONTAL AIR MASS ON FRIDAY WILL BE QUITE
COOL WITH TEMPERATURES IN CENTRAL/NORTHERN MN LIKELY REMAINING IN
THE 50S DURING THE AFTERNOON. WE MIGHT EVEN BE A LITTLE TOO WARM
WITH FRIDAY`S TEMPERATURES...ESPECAILLY GIVEN THE DECENT CHANCE
FOR A BROKEN TO OVERCAST DECK OF MID CLOUDS. THE WEATHER SHOULD
REMAIN DRY ON FRIDAY. ON SATURDAY...A WEST COAST TROUGH WILL EJECT
EAST OUT OF CALIFORNIA AND PASS OVER THE ROCKIES BEFORE SLOWLY
MAKING ITS TRACK ACROSS THE REGION SUN-TUE. A SURFACE LOW IS
FORECAST TO TRACK FROM THE CENTRAL PLAINS...ACROSS IA...AND
EVENTUALLY REACHING EASTERN LAKE SUPERIOR BY TUESDAY. THAT PUTS
MN/WI IN A PRETTY GOOD SPOT FOR WIDESPREAD RAIN SUNDAY INTO
MONDAY. THE 06.18Z AND 07.00Z RUNS OF THE GFS DEPICT SIMILIAR
SOLUTIONS...A CHANGE FROM THE FEW RUNS BEFORE THESE LAST TWO WHICH
HAD A LOT OF RUN-TO-RUN VARIABILITY IN HOW IT HANDLED THE
PROGRESSION OF THIS SURFACE LOW EARLY NEXT WEEK. THE GFS IS
HEAVIER WITH THE QPF WHEN COMPARED TO THE ECMWF...BECAUSE IT IS
ALSO SLOWER...DEEPER...AND FARTHER SOUTH THAN THE ECMWF. THE ECMWF
HAS ALSO HAD A COUPLE RUNS NOW WITH BETTER CONSISTENCY. WE TRENDED
THE TEMPS A BIT COOLER MON-WED...WITH THE FREEZING LEVEL JUST A
COUPLE THOUSAND FEET OFF THE GROUND TUE-WED. TEMPERATURES REALLY
DO NOT START TO MODIFY UNTIL AT LEAST THURSDAY. SO...MN/WI IS IN
FOR A COOL WEEK AFTER THE RAIN MOVES TUE-TUE NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 1020 PM CDT WED MAY 6 2015
WAITING FOR THE NEXT BATCH OF SHOWERS AND THUNDERSTORMS TO LIFT
NORTHEAST FROM EASTERN NE AND NORTHWEST IA. THIS ACTIVITY WILL
WANE A BIT...BUT WILL OVERSPREAD THE AREA LATE TONIGHT AND
THURSDAY MORNING. BKN-OVC MVFR CIGS WILL DEVELOP AS THIS AREA
ARRIVES. THEN EXPECT A BREAK DURING THE AFTERNOON...WITH
POTENTIAL FOR MORE DEVELOPMENT /THUNDERSTORMS/ LATE AFTERNOON.
SOUTHEAST WINDS SHIFT TO THE SOUTHWEST ON THURSDAY...THEN TO THE
NORTHWEST ON THURSDAY EVENING. SPEEDS AOA 12KTS THROUGH THE
PERIOD.
KMSP...
MAINLY DRY OVERNIGHT...UNTIL NE/IA BATCH OF PRECIPITATION MOVES
IN. EXPECT THIS AROUND/AFTER 12Z...PERSISTING THROUGH THE MORNING
ALONG WITH MVFR CONDITIONS /BUT SHOULD STAY ABOVE 1700 FT/. BRIEF
BREAK IN THE EARLY AFTERNOON...THEN REDEVELOPMENT /POSSIBLY WITH
THUNDER/ OCCURS BY LATE AFTERNOON.
/OUTLOOK FOR KMSP/
FRI...VFR. WINDS NW 10 KTS.
SAT...VFR. WINDS NE 10 KTS.
SUN...MVFR LIKELY WITH IFR POSSIBLE IN SHWRS/TSTMS. WINDS NE 10-15
KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...CLF
AVIATION...LS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
915 PM CDT FRI MAY 8 2015
.UPDATE...
OVERALL DEEP LONGWAVE TROUGH OVER THE WESTERN CONUS IS PRODUCING
STORMS OVER THE CENTRAL PLAINS WILL GRADUALLY TRAVERSE TO THE E/NE
TONIGHT. NOT EXPECTING ANY OF THESE STORMS TO HOLD TOGETHER AS
INSTABILITY IS WANING AND FORCING WILL REMAIN OFF TO THE N/NW OF THE
REGION. CLOUDS WILL GRADUALLY BE ON THE INCREASE TONIGHT BUT
BUILDING HEIGHTS ALOFT OVERNIGHT FROM THE SW WILL GRADUALLY KEEP MOST
OF THE AREA DRY...OTHER THAN WHAT IS CURRENTLY OUT THERE IN THE W/SW
AREAS. THE HRRR AND A FEW GLOBAL MODELS BRING SOME SHOWERS BACK INTO
THE NW DELTA LATE TONIGHT BUT NOT EXPECTING MUCH ACTIVITY UNTIL LATER
TOMORROW AFTERNOON. ONLY CHANGES TONIGHT WERE TO LOWER TEMPS SLIGHTLY
IN THE SE DUE TO SKIES BEING LESS CLOUDY AND DEWPOINTS BEING LOWER
THAN GUIDANCE. REST OF THE FORECAST IS ON TRACK AND UPDATES ARE OUT.
/DC/
&&
.AVIATION...
HAVE FOLLOWED A FORECAST BASED ON PERSISTENCE WITH LIFR
FOG/STRATUS EXPECTED AGAIN IN THE HBG/PIB AREA DURING THE EARLY
MORNING HOURS. HRRR GUIDANCE SUGGESTS MVFR AND PERHAPS IFR CATEGORY
STRATUS COULD IMPACT THE GLH DURING THE MORNING HOURS ALONG WITH A
FEW SHRA/TSRA WHERE DEEPER SOUTHWEST FLOW AND ASCENT WILL BE PRESENT.
OTHERWISE EXPECT VFR CONDITIONS TO PREVAIL THROUGH SATURDAY EVENING.
/EC/
&&
.PREV DISCUSSION... /ISSUED 322 PM CDT FRI MAY 8 2015/
SHORT TERM...TONIGHT THROUGH SUNDAY...A FEW SHOWERS AND
THUNDERSTORMS ARE OCCURRING THIS AFTERNOON MAINLY WEST OF THE
MISSISSIPPI RIVER AND EXPECT THIS TREND TO CONTINUE INTO THE EARLY
EVENING HOURS. HI-RES MODELS INDICATE ANY THUNDERSTORM ACTIVITY TO
DISSIPATE BY MID EVENING AS ANY UPPER SUPPORT FOR THE CONVECTION IS
WELL WEST OF THE AREA. EXPECT SKIES TO BECOME MOSTLY CLEAR OVERNIGHT
WITH LOWS IN THE MID/UPPER 60S. SATURDAY WILL BE A SIMILAR DAY AS
TODAY WITH UPPER RIDGING PREVAILING OVER THE BULK OF THE AREA AND
THE BEST MOISTURE AND INSTABILITY REMAINS TO OUR WEST. ONCE AGAIN A
FEW SHOWERS AND THUNDERSTORMS MAY MAKE IT AS FAR EAST AS THE
MISSISSIPPI RIVER BEFORE RUNNING INTO SOME CAPPING AND DRIER AIR.
EXPECT ANY SHOWERS IN THE WEST TO DISSIPATE BY MID EVENING ONCE
AGAIN WITH MAINLY CLEAR SKIES AND LOWS BACK INTO THE 60S ONCE AGAIN.
LITTLE WILL CHANGE ON SUNDAY...BUT THE MID LEVEL RIDGE OVER THE AREA
WILL BEGIN TO SLOWLY SHIFT TO THE EAST. THE BEST CHANCES FOR ANY
SHOWER/ THUNDERSTORM ACTIVITY WILL CONTINUE TO BE ALONG AND WEST OF
THE RIVER WITH VERY WARM HIGHS UP INTO THE UPPER 80S ONCE AGAIN.
EXPECT ANY THUNDERSTORM ACTIVITY TO REMAIN BELOW SEVERE LIMITS
THROUGH THE WEEKEND...BUT A STRONG STORM OR TWO CANNOT BE RULED OUT
EACH AFTERNOON.
BY SUNDAY NIGHT INTO MONDAY...MID LEVEL RIDGING WILL BEGIN TO SHIFT
FURTHER EAST AS MID LEVEL TROUGHING DEEPENS OVER THE PLAINS. A COLD
FRONTAL BOUNDARY WILL MOVE INTO THE DELTA MONDAY AFTERNOON AND
SLOWLY DRIFT FURTHER SOUTH ACROSS THE AREA INTO THE EVENING HOURS.
CURRENTLY IT LOOKS LIKE THE BEST FORCING WILL BE JUST NORTH OF OUR
AREA ON MONDAY...BUT THERE WILL BE SOME DECENT LAPSE RATE AROUND 6.5
C/KM AND MOISTURE WITH PWATS AROUND 1.6-1.7 INCHES DURING THE
AFTERNOON AND EVENING AS THE BOUNDARY DRIFTS SOUTH. NEGATIVE FACTORS
WILL BE LITTLE FLOW IN THE LOW LEVELS AND HEIGHTS RANGING FROM H582-
H585. DUE TO THESE FACTORS STRONG TO POSSIBLY SEVERE STORMS CANNOT
BE RULED OUT MONDAY AFTERNOON/EVENING...BUT DUE TO THE NEGATIVE
FACTORS AND THE UNCERTAINTY WILL HOLD OFF ANY MENTION IN THE HWO.
DID NOT MAKE ANY CHANGES TO THE FORECAST PAST MONDAY...SO WILL
ATTACH THE APPLICABLE PORTIONS OF THE PREVIOUS LONG TERM AFD
BELOW. /15/
LONG TERM...THE NEARLY STATIONARY COLD FRONT IS STILL EXPECTED TO
DRIFT OVER OUR CWA TUESDAY AND SERVE AS A FOCUS FOR CONVECTION
THROUGH WEDNESDAY. MODELS DIFFER ON HOW FAR SOUTH THE BOUNDARY WILL
BE COME WEDNESDAY MORNING WITH THE CANADIAN AND GFS OVER OUR SOUTHERN
ZONES AND THE ECMWF ACROSS OUR NORTH. HAVE LEANED TOWARD THE
GFS/CANADIAN WITH COOLER AND DRIER AIR LIMITING CONVECTION NORTH OF
THE FRONT TUESDAY NIGHT AND WEDNESDAY. MODEL DIFFERENCES CONTINUE
THROUGH THE END OF THE WEEK BUT A SOUTHERN STREAM DISTURBANCE WILL
BRING AN INCREASE IN RAIN CHANCES FROM THE SOUTHWEST WEDNESDAY NIGHT
INTO THURSDAY WITH DISTURBED WEATHER CONTINUING FRIDAY. AFTERNOON
HIGHS WILL BE NEAR NORMAL IN THE LOWER 80S BUT THE CONTINUATION OF
LOW LEVEL MOISTURE WILL HELP HOLD MORNING LOWS ABOVE NORMAL...GENERALLY
IN THE LOW TO MID 60S WEDNESDAY THROUGH FRIDAY. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 66 86 65 87 / 6 10 6 8
MERIDIAN 64 87 64 88 / 4 4 3 6
VICKSBURG 68 85 67 87 / 15 13 9 13
HATTIESBURG 62 88 64 89 / 3 2 3 5
NATCHEZ 68 84 67 86 / 10 11 7 15
GREENVILLE 68 84 68 86 / 17 20 17 17
GREENWOOD 67 85 67 87 / 10 17 12 12
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/EC/15/22
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
133 PM CDT Thu May 7 2015
.UPDATE:
Issued at 1233 PM CDT Thu May 7 2015
Updated the grids based on current trends. Convection has started
to dvlp prior to noon and should continue to expand in coverage
thru the aftn. There should be two areas of better coverage
though. One area will be across cntrl/NE MO into w cntrl IL in
assoc with ongoing convection that has dvlpd in advance of a
complex mvng out of ern KS this mrng and the other is in assoc
with a vort max mvng NE out of SW MO. This feature is fcst to be
near STL by 00Z this evng. I expect the precip coverage to expand
thru the aftn as this feature approaches the metro area. Both
areas should move NE of the CWA by early evng allowing for a break
in the activity overnight. Luckily shear is quite limited, only
approaching 20kts by this evng so severe storms are not expected.
&&
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday through Wednesday)
Issued at 410 AM CDT Thu May 7 2015
Southwest flow aloft will continue to try to bring deeper moisture
back to the Mississippi Valley Friday into the weekend. It`s
difficult to really pick out a time when thunderstorms are more or
less likely for Friday through Sunday as the foci for precipitation
will likely be fast-moving shortwaves moving over the area in the
southwest flow aloft, as well as low level boundaries from
convection. Models have the synoptic front generally draped across
northern Missouri...possibly dipping down as far south as the
Missouri river at times as it is forced south by convection. Have
some flavor of 40-70% PoPs across the area for Friday through
Saturday night with the higher end PoPs closer to the synoptic
front. Guidance has the high amplitude closed wave finally opening
up and moving int the Great Plains on Sunday with the resulting
surface low moving northeast from Kansas through Iowa into the Great
Lakes Sunday night through Monday. Resulting cold front should
sweep through the forecast area late Sunday night into early Monday
morning. Cooler and drier air will bring an end to the rain chances
by most likely by Monday afternoon. Above normal temperatures will
continue ahead of the FROPA on Monday with highs mainly in the 80s
and lows in the mid 60s. Medium range guidance drops temperatures
back below normal for Tuesday and Wednesday showing highs mainly 65
to 70 and lows mainly in the upper 40s and low 50s.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1233 PM CDT Thu May 7 2015
Low confidence fcst due to convective timing and coverage issues.
SHRAs/TSTMs had already begun to initiate by late mrng and should
continue to expand in coverage this aftn. Best coverage drng the
aftn should be across cntrl/NE MO into w cntrl IL. Another area of
precip is dvlpng across the ern Ozarks in response to an upper lvl
disturbance which is lifting towards the STL metro area. Any
heavier convective element that impacts a terminal will likely
cause IFR VSBYs in heavy rain. This activity should lift NE of the
TAF sites by early this evng allowing for a break for a good
portion of the night before either more precip moves in from the
west late tonight or...more likely...addtnl convection dvlps late
Friday mrng.
Specifics for KSTL:
Convection currently forming across the ern Ozarks will have to be
watched as it lifts NNE this aftn. Do not have any more than VCTS
in the TAF as I`m not confident on the coverage of storms this
aftn. Any stronger storms impacting the terminal will have the
ability to drop the VSBY to IFR. Whatever dvlps this aftn should
be past the terminal by early evng. The rest of the night appears
dry attm. More rain is expected on Friday. Existing overnight
convection may approach the terminal towards 12Z...but if that
scenario doesn`t pan out then addtnl convection should dvlp once
again like it has today. Either way...it appears there will be at
least scttrd SHRAs/TSTMs thru a good portion of tomorrow.
2%
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
704 AM CDT Thu May 7 2015
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday through Wednesday)
Issued at 410 AM CDT Thu May 7 2015
Southwest flow aloft will continue to try to bring deeper moisture
back to the Mississippi Valley Friday into the weekend. It`s
difficult to really pick out a time when thunderstorms are more or
less likely for Friday through Sunday as the foci for precipitation
will likely be fast-moving shortwaves moving over the area in the
southwest flow aloft, as well as low level boundaries from
convection. Models have the synoptic front generally draped across
northern Missouri...possibly dipping down as far south as the
Missouri river at times as it is forced south by convection. Have
some flavor of 40-70% PoPs across the area for Friday through
Saturday night with the higher end PoPs closer to the synoptic
front. Guidance has the high amplitude closed wave finally opening
up and moving int the Great Plains on Sunday with the resulting
surface low moving northeast from Kansas through Iowa into the Great
Lakes Sunday night through Monday. Resulting cold front should
sweep through the forecast area late Sunday night into early Monday
morning. Cooler and drier air will bring an end to the rain chances
by most likely by Monday afternoon. Above normal temperatures will
continue ahead of the FROPA on Monday with highs mainly in the 80s
and lows in the mid 60s. Medium range guidance drops temperatures
back below normal for Tuesday and Wednesday showing highs mainly 65
to 70 and lows mainly in the upper 40s and low 50s.
Carney
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 640 AM CDT Thu May 7 2015
Fairly complex aviation forecast with southwest flow aloft in
place and a number of weak disturbances progged to translate
within the flow across the area. Adding to the difficulty are
model solutions that vary widely with the timing and placement of
the thunderstorms. Present thinking is that thunderstorms will
develop by early afternoon in central MO and then move east-
northeastward impacting both KCOU and KUIN which is reflected in
the TEMPO groups. Confidence is a bit less for the St. Louis
terminals as they may be on the southern end of the thunderstorms
and hence just went with a PROB30. One of the disturbances will
move across the region tonight and this should produce another
round of showers and thunderstorms from late evening into the
overnight hours. Since confidence is low on the specifics of timing
and coverage I only forecast showers and VCTS for this later
round. Outside of the showers and thunderstorms, VFR flight
conditions should prevail.
Specifics for KSTL:
Present thinking is that thunderstorms will develop by early
afternoon in central MO and then move east-northeastward. The main
question is if they will impact KSTL. Confidence is low as KSTL
may be on the southern end of the thunderstorms and hence just
went with a PROB30. A disturbance aloft will move across the
region tonight and this should produce another round of showers
and thunderstorms that could impact KSTL late tonight into Friday
morning. Since confidence is low on the specifics of timing and
thunder coverage I only forecast showers and VCTS for this later
round. Outside of the showers and thunderstorms, VFR flight
conditions should prevail.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
411 AM CDT Thu May 7 2015
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday through Wednesday)
Issued at 410 AM CDT Thu May 7 2015
Southwest flow aloft will continue to try to bring deeper moisture
back to the Mississippi Valley Friday into the weekend. It`s
difficult to really pick out a time when thunderstorms are more or
less likely for Friday through Sunday as the foci for precipitation
will likely be fast-moving shortwaves moving over the area in the
southwest flow aloft, as well as low level boundaries from
convection. Models have the synoptic front generally draped across
northern Missouri...possibly dipping down as far south as the
Missouri river at times as it is forced south by convection. Have
some flavor of 40-70% PoPs across the area for Friday through
Saturday night with the higher end PoPs closer to the synoptic
front. Guidance has the high amplitude closed wave finally opening
up and moving int the Great Plains on Sunday with the resulting
surface low moving northeast from Kansas through Iowa into the Great
Lakes Sunday night through Monday. Resulting cold front should
sweep through the forecast area late Sunday night into early Monday
morning. Cooler and drier air will bring an end to the rain chances
by most likely by Monday afternoon. Above normal temperatures will
continue ahead of the FROPA on Monday with highs mainly in the 80s
and lows in the mid 60s. Medium range guidance drops temperatures
back below normal for Tuesday and Wednesday showing highs mainly 65
to 70 and lows mainly in the upper 40s and low 50s.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1053 PM CDT Wed May 6 2015
Just mid-high level cloudiness late tonight. Diurnal cumulus clouds
will develop again late Thursday morning and afternoon with
scattered showers and storms expected as an upper level
disturbance moves through the area with a moist and unstable
atmosphere. Will include VCTS for the taf sites for Thursday
afternoon into the evening. S-sely surface winds late tonight,
then gusty sly winds on Thursday.
Specifics for KSTL: Just some mid-high level clouds late tonight,
then diurnal cumulus clouds will develop late Thursday morning and
afternoon with isolated to scattered showers/storms for late
Thursday afternoon and evening. S-sely surface wind late tonight,
becoming strong and gusty again from a sly direction on Thursday.
The surface wind will weaken Thursday night.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 86 68 84 68 / 30 50 70 40
Quincy 83 65 79 62 / 60 60 70 50
Columbia 82 65 78 64 / 60 60 70 50
Jefferson City 84 65 80 65 / 60 60 70 50
Salem 85 66 84 67 / 20 20 50 50
Farmington 84 65 81 65 / 30 50 60 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
340 AM CDT Thu May 7 2015
.SHORT TERM: (Today and Tonight)
Issued at 339 AM CDT Thu May 7 2015
Short-range guidance has been consistently spitting out some sunrise
surprise showers for the past few runs. The RAP might be a little
overdone as it looks like it`s trying to break pieces of the MCV
currently over Oklahoma off and spread them northeast across the
area. That being said, radar is picking up some very light echos
developing over the eastern Ozarks at this time...so the possibility
for isolated showers does seem to be increasing this morning.
Aside from any morning showers, expect most of the morning and early
afternoon to be dry. Should see highs today similar to if not a bit
warmer than Wednesday. The MCV should lift up into the area and
provide a lifting mechanism later this afternoon. Additionally,
the cold front now over western Nebraska/Kansas will drift into
western/northwestern Missouri by late this afternoon providing an
additional focusing mechanism. Think likely PoPs across central and
northeast Missouri into west central Illinois look good with chance
PoPs further to the southeast still look good for the afternoon into
early evening. PoPs for the rest of the night are less certain
though, and short-range guidance seems to be having as much trouble
as I am figuring out how to handle the situation. MOS guidance
ranges from low chance to categorical across the area. GFS and NAM
do show a weak to moderate low level jet setting up during the
evening, with a few waves of moisture convergence in the warm sector
ahead of the front. Baroclinicity is weak, but present, so I cannot
rule out scattered to possibly numerous showers and
thunderstorms...particularly closer to the front in central and
northeast Missouri.
Carney
.LONG TERM: (Friday Night through Next Wednesday) Issued at 355 PM
CDT Wed May 6 2015
Meanwhile, a large low pressure system will be dropping southward
along the west coast before briefly closing off over CA and then
migrating slowly eastward through the desert southwest. This
feature then lifts northeastward into the plains and induces lee
cyclogenesis near the OK/TX panhandles on Saturday. A trailing
cold front will have nosed into northern MO and stalled on Friday
night when the flow aloft becomes parallel to the boundary, but
the developing surface low will start to lift the boundary back
northward on Saturday as a warm front. There is still some
question regarding how far south the boundary will progress before
it starts to lift back to the north, and this could affect both
high temperatures and precipitation chances for parts of the CWA.
Much like the low pressure system which was moving slowly
northeastward late this afternoon, the aforementioned low pressure
system is also forecast to move slowly northeastward with time
over the weekend, which will keep periodic SHRA/TSRA chances in
the forecast through the weekend and into early next week. The
cold front associated with this system finally pushes through the
area on Sunday night and Monday. High pressure builds in behind
the front on Monday night, and precipitation chances diminish
accordingly.
Recent models runs are in general agreement that 0-6 km shear
remains fairly weak across the LSX CWA, at least until Sunday/Sunday
night into Monday when models show it increasing to around 30-50
kts. This suggests that although a few strong storms are possible
over the next few days, widespread severe weather is unlikely. Later
shifts will need to keep an eye on the evolution of the
Sunday/Monday system and the potential for severe weather given
the forecast values of shear and instability ahead of the
approaching cold front.
Temperatures will remain unusually warm through the weekend
followed by cooler temperatures early next week behind the cold
front.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1053 PM CDT Wed May 6 2015
Just mid-high level cloudiness late tonight. Diurnal cumulus clouds
will develop again late Thursday morning and afternoon with
scattered showers and storms expected as an upper level
disturbance moves through the area with a moist and unstable
atmosphere. Will include VCTS for the taf sites for Thursday
afternoon into the evening. S-sely surface winds late tonight,
then gusty sly winds on Thursday.
Specifics for KSTL: Just some mid-high level clouds late tonight,
then diurnal cumulus clouds will develop late Thursday morning and
afternoon with isolated to scattered showers/storms for late
Thursday afternoon and evening. S-sely surface wind late tonight,
becoming strong and gusty again from a sly direction on Thursday.
The surface wind will weaken Thursday night.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 86 68 84 68 / 30 50 70 40
Quincy 83 65 79 62 / 60 60 70 50
Columbia 82 65 78 64 / 60 60 70 50
Jefferson City 84 65 80 65 / 60 60 70 50
Salem 85 66 84 67 / 20 20 50 50
Farmington 84 65 81 65 / 30 50 60 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
815 AM MDT THU MAY 7 2015
.UPDATE...
SNOW IS FALLING AT LIVINGSTON...NYE AND BOZEMAN PASS THIS MORNING
THANKS TO WET BULB COOLING TO 32 F WITHIN THE BOUNDARY LAYER. THE
FORECAST WAS UPDATED TO REFLECT THIS WITH A MIX OF RAIN AND SNOW
NOW MENTIONED ALONG THE FOOTHILLS THROUGH THE MORNING. ROADS ARE
JUST WET AND SHOULD REMAIN THAT WAY. THE HRRR APPEARS TO HAVE A
GOOD HANDLE ON THIS SCENARIO AND CONFIRMS THAT A DOWNWARD TREND
SHOULD COMMENCE IN PRECIPITATION THIS AFTERNOON. POP-WISE...THE
FORECAST WAS ADJUSTED TO REFLECT CATEGORICAL POPS OF 100 PERCENT
IN AND AROUND LIVINGSTON THIS MORNING...BUT CONVERSELY WE CHOSE
TO DROP THE SLIGHT CHANCE OF RAIN SHOWERS COMPLETELY OUT OF THE
FORECAST FOR BILLINGS BASED ON RECENT RADAR AND HRRR MODEL TRENDS.
FINALLY...WE LOWERED FORECAST HIGHS SEVERAL DEGREES IN AND NEAR
THE FOOTHILLS LIKE AT LIVINGSTON GIVEN CLOUDS...MOISTURE AND AN
EASTERLY LOW-LEVEL FLOW IN THOSE AREAS TODAY. SCHULTZ
&&
.SHORT TERM...VALID FOR TDY AND FRI...
EARLY THIS MORNING...RADAR RETURNS ARE ALREADY BEGINNING TO
INCREASE OVER THE SOUTHWESTERN MOUNTAINS AND FOOTHILLS. THIS IS
ASSOCIATED WITH A SHORT WAVE MOVING OUT OF UTAH. AS THIS
CONTINUES TO MOVE NORTH...RAIN CHANCES WILL INCREASE THROUGH THE
MORNING. WINDS ACROSS THE AREA ARE GOING TO REMAIN OUT OF NORTH TO
NORTHEAST. WITH THE UPSLOPE COMPONENT ALONG WITH THE AREA STILL
SOMEWHAT IN A FAVORABLE REGION OF A 250MB JET...AND THROW IN SOME
QG FORCING...RAIN LOOKS LIKELY OVER THE MOUNTAINS AND WESTERN
ZONES DURING THE DAY TODAY. HI-RES GUIDANCE SHOW PRECIP PUSHING
ALMOST TO BILLINGS...SO HAVE LEFT A SLIGHT CHANCE IN FOR THE CITY.
MOST OF THE RAIN ASSOCIATED THE A SHORTWAVE IN THE DAKOTAS HAS
ALREADY MOVED OUT OF MONTANA. HAVE REMOVED POPS FROM MOST OF CARTER
AND FALLON COUNTIES...LEAVING MUCH OF THE AREA EAST OF BILLINGS
AND SHERIDAN DRY THROUGH THE DAY.
OVERNIGHT RAIN CHANCES WILL DECREASE SOME AS THIS AROUND OF ENERGY
DISSIPATES...BUT THE BEST CHANCES IN THE SHORT TERM WILL BE
FRIDAY EVENING. AS THE CLOSED LOW MOVES INTO THE FOUR CORNERS
REGION...THE AREA WILL SEE ANOTHER ROUND OF ENERGY MOVE IN. WINDS
WILL SHIFT TO MORE EASTERLY DURING THE DAY FRIDAY AND MOISTURE
WILL BE INCREASING. THIS WILL COMBINED WITH INCREASINGLY DIFFLUENT
FLOW ALOFT TO GIVE MUCH OF THE AREA A SHOT AT RAIN. TEMPERATURES
AT 850MB CONTINUE TO BE IN THE 0 TO +3 DEGREE RANGE ACROSS THE
AREA. IN THE MOUNTAINS THIS WILL RESULT IN SNOWFALL OF 2 TO 4
INCHES OF SNOW...SOME LOCALLY HIGHER AMOUNTS CLOSER TO 6...FRIDAY
INTO EARLY SATURDAY. THE FOOTHILLS WILL SEE LESS...GENERALLY A
COUPLE OF INCHES OF SNOW OVER 24 HOURS. MAINTAINED THE PREVIOUS
FORECAST OF ONLY RAIN IN BILLINGS AND POINTS FURTHER EAST AS
GUIDANCE CONTINUES TO SHOW WETBULB TEMPERATURES REMAIN SLIGHTLY
ABOVE FREEZING. REIMER
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MEDIUM RANGE GUIDANCE IN FAIRLY GOOD AGREEMENT INTO THE EXTENDED.
SATURDAY STILL LOOKING LIKE A COOL AND WET DAY UNDER UPPER
DIFFLUENT FLOW AHEAD OF UPPER LOW DRIFTING EAST ACROSS THE
SOUTHERN ROCKIES. AS SYSTEM SPINS UP INTO THE PLAINS...A DRIER
NORTHWEST FLOW PUSHES INTO MOST OF OUR AREA FOR SUNDAY. THE MAIN
CHANGES INTO THE EXTENDED WAS TO LOWER PRECIPITATION CHANCES FOR
SUNDAY WITH THE SYSTEM TRENDING FURTHER SOUTHEAST. AS UPPER LOW
DRIFTS EAST INTO THE MIDWEST...A NORTH/NORTHWEST FLOW DOMINATES
INTO TUESDAY FOR OVERALL DRY CONDITIONS. ONCE WEDNESDAY
APPROACHES...INTRODUCED CLIMO PRECIP CHANCES AS FLOW BECOMES MORE
SOUTHWEST AGAIN AND INSTABILITY INCREASES ACROSS THE REGION. NO
ORGANIZED SYSTEM...JUST MAINLY SCATTERED AFTERNOON SHOWERS.
AS FOR TEMPERATURES...READINGS COULD BE AS MUCH AS 20 DEGREES
BELOW NORMAL FOR SATURDAY IF THE CLOUDY AND WET CONDITIONS EVOLVE
AS EXPECTED. A SLOW MODERATION IN TEMPERATURES EXPECTED THE REST
OF THE EXTENDED. THE NORTHWEST FLOW BEHIND THE WEEKEND SYSTEM WILL
KEEP TEMPERATURES BELOW NORMAL INTO MONDAY. FRIEDERS
&&
.AVIATION...
AREAS OF RAIN AND SNOW SHOWERS WILL OCCUR IN THE MOUNTAINS AND
FOOTHILLS WITH FREQUENT TO OCCASIONAL LIFR...ESPECIALLY THIS
MORNING. CONDITIONS WILL SLOWLY IMPROVE THIS AFTERNOON IN THESE
AREAS. ALSO...EXPECT LOCAL MVFR AROUND KBHK AT TIMES THIS
MORNING. OTHERWISE...VFR CONDITIONS WILL PREVAIL WITH A MID LEVEL
CLOUD DECK. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 052 038/047 036/043 035/053 035/058 038/065 044/069
1/E 14/W 77/R 61/B 11/B 11/B 12/W
LVM 044 033/046 033/044 032/051 030/057 035/063 038/066
+/W 26/W 77/O 52/W 12/W 22/W 33/W
HDN 055 036/054 036/045 033/055 033/060 034/066 041/070
1/E 13/W 77/R 61/B 11/B 11/B 12/W
MLS 056 036/056 037/050 033/055 034/060 038/064 042/069
1/E 12/W 55/R 31/B 10/B 11/B 12/W
4BQ 055 034/058 038/045 031/050 032/056 034/062 041/068
1/E 12/W 66/R 62/W 10/B 11/B 12/W
BHK 054 032/056 034/050 031/051 031/056 034/059 038/065
1/N 11/E 34/R 21/B 10/B 11/B 12/W
SHR 052 033/053 035/041 030/047 030/054 033/062 039/066
4/W 14/W 78/O 63/W 21/B 11/B 12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1256 PM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU MAY 7 2015
SHOWERS AND THUNDERSTORMS CONTINUE MAINLY ACROSS THE SOUTHEAST PART
OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM
AND COLD FRONT JUST TO THE WEST OF THE FORECAST AREA AT THIS TIME.
MODELS ARE FAIRLY CONSISTENT KEEPING THE CURRENT PRECIPITATION
ACROSS MAINLY THE EASTERN PART OF THE FORECAST AREA THROUGH DAYBREAK
OR INTO THE MORNING HOURS...BUT WHEN IT MOVES OUT THERE SHOULD BE A
BREAK IN THE PRECIPITATION FOR A TIME. THE COLD FRONT TO THE WEST OF
THE FORECAST AREA THIS MORNING IS EXPECTED TO MOVE THROUGH THE AREA
DURING THE DAY. MODELS HAVE SOME DIFFERENCES ON HOW FAST IT MOVES
THROUGH. THE GFS HAS IT MOST OF THE WAY THROUGH THE FORECAST AREA BY
MID DAY WHILE THE NAM IS SLOWER TO MOVE THROUGH. THE RAP IS CLOSER
TO THE GFS AND MOVES IT THROUGH FASTER. WENT A LITTLE IN BETWEEN AND
HAVE IT IN THE EAST AND SOUTHERN PARTS OF THE FORECAST AREA MID
AFTERNOON. THE LOCATION OF THE FRONT IS IMPORTANT AS THE NEXT UPPER
LEVEL WAVE MOVES INTO THE FORECAST AREA DURING THE LATE AFTERNOON
AND INTO TONIGHT. THE UPPER WAVE MOVES IN FROM THE SOUTHWEST SO THE
PRECIPITATION SHOULD MOVE IN FROM THE SOUTH DURING THE AFTERNOON AND
SPREAD ACROSS MUCH OF THE AREA. THE BEST CHANCES WILL BE IN THE
SOUTH OR SOUTHEAST TONIGHT. WILL HAVE TO WATCH THE SOUTHEAST...THIS
IS THE AREA WITH ONGOING FLOODING AND THE AREA THE MOST LIKELY TO
HAVE PRECIPITATION TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU MAY 7 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC LOW WILL EXIST OVER THE
SOUTHWESTERN CONUS TO START THE LONG-TERM FORECAST PERIOD AT 12Z
FRIDAY...WITH UPPER TROPOSPHERIC RIDGING OVER THE EASTERN CONUS.
THIS UPPER TROPOSPHERIC LOW IS EXPECTED TO MOVE NORTHEAST FRIDAY
THROUGH EARLY NEXT WEEK...LIKELY CLEARING THE CENTRAL PLAINS
SATURDAY INTO SUNDAY. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED ACROSS THE REGION DURING THE EARLY TO MIDDLE PART OF NEXT
WEEK.
GUIDANCE SUGGESTS UPPER TROPOSPHERIC THERMAL ADVECTION AHEAD OF THE
APPROACHING LOW WILL PROMOTE PRECIPITATION PRODUCTION ACROSS OUR AREA
FRIDAY THROUGH EARLY NEXT WEEK...WITH PERHAPS A RELATIVELY DRY
PERIOD AT SOME POINT EARLY NEXT WEEK AS THE AFOREMENTIONED UPPER
TROPOSPHERIC LOW CLEARS THE REGION. THAT SAID...GUIDANCE ALSO
SUGGESTS MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS...EMBEDDED WITHIN
THE DEVELOPING QUASI-ZONAL FLOW...COULD PROMOTE ADDITIONAL
PRECIPITATION CHANCES DURING THE MIDDLE TO LATE PART OF NEXT WEEK.
GIVEN ALL THIS...POPS REMAIN INTACT ACROSS THE AREA DURING MUCH OF
THE LONG-TERM FORECAST PERIOD...WITH THE HIGHEST POPS EXISTING
BETWEEN SATURDAY AFTERNOON AND SATURDAY NIGHT AS THE UPPER
TROPOSPHERIC LOW CLEARS THE AREA.
A DRIER BOUNDARY-LAYER AIR MASS...ALONG WITH MODEST UPPER
TROPOSPHERIC LAPSE RATES...SHOULD KEEP SEVERE WEATHER AT BAY FRIDAY
INTO FRIDAY NIGHT...WITH GUIDANCE SUGGESTING POTENTIAL ENERGY WILL
REMAIN AT OR BELOW 500J/KG ACROSS MUCH OF THE CWA. THAT WILL CHANGE
FOR PORTIONS OF THE REGION SATURDAY INTO SATURDAY NIGHT HOWEVER AS
BOUNDARY-LAYER MOISTURE FLUX ACROSS THE CENTRAL PLAINS...ALONG WITH
INCREASING UPPER TROPOSPHERIC LAPSE RATES WITH THE APPROACH OF THE
UPPER TROPOSPHERIC LOW...PROMOTES POTENTIAL ENERGY ON THE ORDER OF
~1500J/KG ACROSS SOUTHERN PORTIONS OF THE CWA...AND LOWER POTENTIAL
ENERGY AS ONE MOVES NORTH ACROSS THE AREA. THESE POTENTIAL ENERGY
VALUES...WORKING IN CONCERT WITH DEEP-LAYER BULK SHEAR VALUES OF
AROUND 50KTS...COULD PRESENT YET ANOTHER OPPORTUNITY FOR SEVERE
WEATHER ACROSS PORTIONS OF THE CWA SATURDAY AFTERNOON INTO SATURDAY
NIGHT...ESPECIALLY ACROSS OUR SOUTHERN COUNTIES SOUTH OF HIGHWAY 6.
GIVEN THIS...WILL CONTINUE MENTIONING SEVERE WEATHER IN THE HWO
SATURDAY INTO SATURDAY NIGHT GENERALLY SOUTH OF HIGHWAY 6. DRIER
BOUNDARY-LAYER AIR AND DECREASING UPPER TROPOSPHERIC LAPSE RATES
SHOULD THEN ALLOW FOR A DECREASING SEVERE WEATHER THREAT AS WE MOVE
INTO THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM CDT THU MAY 7 2015
MVFR CIGS WILL PERSIST THROUGH MUCH OF THE PERIOD WITH A FEW
SHOWERS AND THUNDERSTORMS POSSIBLE DURING THE EVENING HOURS AHEAD
OF A SLOW MOVING COLD FRONT. EXPECT TO SEE A SLIGHT SHIFT IN WINDS
WITH THIS FRONT...FROM NORTHWESTERLY TO MORE NORTHERLY TOWARDS
EARLY MORNING FRIDAY...WITH SOME IFR STRATUS POSSIBLE IN ITS WAKE.
FOR THE TIME BEING...OPTED TO KEEPS CIGS AT MVFR LEVELS FOR
FRIDAY...BUT SOME MODEL GUIDANCE IS HINTING THIS MAY BE A BIT TOO
OPTIMISTIC FOR THE MORNING HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
621 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU MAY 7 2015
SHOWERS AND THUNDERSTORMS CONTINUE MAINLY ACROSS THE SOUTHEAST PART
OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM
AND COLD FRONT JUST TO THE WEST OF THE FORECAST AREA AT THIS TIME.
MODELS ARE FAIRLY CONSISTENT KEEPING THE CURRENT PRECIPITATION
ACROSS MAINLY THE EASTERN PART OF THE FORECAST AREA THROUGH DAYBREAK
OR INTO THE MORNING HOURS...BUT WHEN IT MOVES OUT THERE SHOULD BE A
BREAK IN THE PRECIPITATION FOR A TIME. THE COLD FRONT TO THE WEST OF
THE FORECAST AREA THIS MORNING IS EXPECTED TO MOVE THROUGH THE AREA
DURING THE DAY. MODELS HAVE SOME DIFFERENCES ON HOW FAST IT MOVES
THROUGH. THE GFS HAS IT MOST OF THE WAY THROUGH THE FORECAST AREA BY
MID DAY WHILE THE NAM IS SLOWER TO MOVE THROUGH. THE RAP IS CLOSER
TO THE GFS AND MOVES IT THROUGH FASTER. WENT A LITTLE IN BETWEEN AND
HAVE IT IN THE EAST AND SOUTHERN PARTS OF THE FORECAST AREA MID
AFTERNOON. THE LOCATION OF THE FRONT IS IMPORTANT AS THE NEXT UPPER
LEVEL WAVE MOVES INTO THE FORECAST AREA DURING THE LATE AFTERNOON
AND INTO TONIGHT. THE UPPER WAVE MOVES IN FROM THE SOUTHWEST SO THE
PRECIPITATION SHOULD MOVE IN FROM THE SOUTH DURING THE AFTERNOON AND
SPREAD ACROSS MUCH OF THE AREA. THE BEST CHANCES WILL BE IN THE
SOUTH OR SOUTHEAST TONIGHT. WILL HAVE TO WATCH THE SOUTHEAST...THIS
IS THE AREA WITH ONGOING FLOODING AND THE AREA THE MOST LIKELY TO
HAVE PRECIPITATION TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU MAY 7 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC LOW WILL EXIST OVER THE
SOUTHWESTERN CONUS TO START THE LONG-TERM FORECAST PERIOD AT 12Z
FRIDAY...WITH UPPER TROPOSPHERIC RIDGING OVER THE EASTERN CONUS.
THIS UPPER TROPOSPHERIC LOW IS EXPECTED TO MOVE NORTHEAST FRIDAY
THROUGH EARLY NEXT WEEK...LIKELY CLEARING THE CENTRAL PLAINS
SATURDAY INTO SUNDAY. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED ACROSS THE REGION DURING THE EARLY TO MIDDLE PART OF NEXT
WEEK.
GUIDANCE SUGGESTS UPPER TROPOSPHERIC THERMAL ADVECTION AHEAD OF THE
APPROACHING LOW WILL PROMOTE PRECIPITATION PRODUCTION ACROSS OUR AREA
FRIDAY THROUGH EARLY NEXT WEEK...WITH PERHAPS A RELATIVELY DRY
PERIOD AT SOME POINT EARLY NEXT WEEK AS THE AFOREMENTIONED UPPER
TROPOSPHERIC LOW CLEARS THE REGION. THAT SAID...GUIDANCE ALSO
SUGGESTS MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS...EMBEDDED WITHIN
THE DEVELOPING QUASI-ZONAL FLOW...COULD PROMOTE ADDITIONAL
PRECIPITATION CHANCES DURING THE MIDDLE TO LATE PART OF NEXT WEEK.
GIVEN ALL THIS...POPS REMAIN INTACT ACROSS THE AREA DURING MUCH OF
THE LONG-TERM FORECAST PERIOD...WITH THE HIGHEST POPS EXISTING
BETWEEN SATURDAY AFTERNOON AND SATURDAY NIGHT AS THE UPPER
TROPOSPHERIC LOW CLEARS THE AREA.
A DRIER BOUNDARY-LAYER AIR MASS...ALONG WITH MODEST UPPER
TROPOSPHERIC LAPSE RATES...SHOULD KEEP SEVERE WEATHER AT BAY FRIDAY
INTO FRIDAY NIGHT...WITH GUIDANCE SUGGESTING POTENTIAL ENERGY WILL
REMAIN AT OR BELOW 500J/KG ACROSS MUCH OF THE CWA. THAT WILL CHANGE
FOR PORTIONS OF THE REGION SATURDAY INTO SATURDAY NIGHT HOWEVER AS
BOUNDARY-LAYER MOISTURE FLUX ACROSS THE CENTRAL PLAINS...ALONG WITH
INCREASING UPPER TROPOSPHERIC LAPSE RATES WITH THE APPROACH OF THE
UPPER TROPOSPHERIC LOW...PROMOTES POTENTIAL ENERGY ON THE ORDER OF
~1500J/KG ACROSS SOUTHERN PORTIONS OF THE CWA...AND LOWER POTENTIAL
ENERGY AS ONE MOVES NORTH ACROSS THE AREA. THESE POTENTIAL ENERGY
VALUES...WORKING IN CONCERT WITH DEEP-LAYER BULK SHEAR VALUES OF
AROUND 50KTS...COULD PRESENT YET ANOTHER OPPORTUNITY FOR SEVERE
WEATHER ACROSS PORTIONS OF THE CWA SATURDAY AFTERNOON INTO SATURDAY
NIGHT...ESPECIALLY ACROSS OUR SOUTHERN COUNTIES SOUTH OF HIGHWAY 6.
GIVEN THIS...WILL CONTINUE MENTIONING SEVERE WEATHER IN THE HWO
SATURDAY INTO SATURDAY NIGHT GENERALLY SOUTH OF HIGHWAY 6. DRIER
BOUNDARY-LAYER AIR AND DECREASING UPPER TROPOSPHERIC LAPSE RATES
SHOULD THEN ALLOW FOR A DECREASING SEVERE WEATHER THREAT AS WE MOVE
INTO THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 618 AM CDT THU MAY 7 2015
CLOUDS ARE EXPECTED TO BREAK UP LATER THIS MORNING OR EARLY THIS
AFTERNOON THEN REDEVELOP LATER TONIGHT. A COLD FRONT IS EXPECTED
TO MOVER THROUGH THE AREA TURNING WINDS TO THE NORTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
320 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 318 AM CDT THU MAY 7 2015
SHOWERS AND THUNDERSTORMS CONTINUE MAINLY ACROSS THE SOUTHEAST PART
OF THE FORECAST AREA. SURFACE ANALYSIS SHOWS A LOW PRESSURE SYSTEM
AND COLD FRONT JUST TO THE WEST OF THE FORECAST AREA AT THIS TIME.
MODELS ARE FAIRLY CONSISTENT KEEPING THE CURRENT PRECIPITATION
ACROSS MAINLY THE EASTERN PART OF THE FORECAST AREA THROUGH DAYBREAK
OR INTO THE MORNING HOURS...BUT WHEN IT MOVES OUT THERE SHOULD BE A
BREAK IN THE PRECIPITATION FOR A TIME. THE COLD FRONT TO THE WEST OF
THE FORECAST AREA THIS MORNING IS EXPECTED TO MOVE THROUGH THE AREA
DURING THE DAY. MODELS HAVE SOME DIFFERENCES ON HOW FAST IT MOVES
THROUGH. THE GFS HAS IT MOST OF THE WAY THROUGH THE FORECAST AREA BY
MID DAY WHILE THE NAM IS SLOWER TO MOVE THROUGH. THE RAP IS CLOSER
TO THE GFS AND MOVES IT THROUGH FASTER. WENT A LITTLE IN BETWEEN AND
HAVE IT IN THE EAST AND SOUTHERN PARTS OF THE FORECAST AREA MID
AFTERNOON. THE LOCATION OF THE FRONT IS IMPORTANT AS THE NEXT UPPER
LEVEL WAVE MOVES INTO THE FORECAST AREA DURING THE LATE AFTERNOON
AND INTO TONIGHT. THE UPPER WAVE MOVES IN FROM THE SOUTHWEST SO THE
PRECIPITATION SHOULD MOVE IN FROM THE SOUTH DURING THE AFTERNOON AND
SPREAD ACROSS MUCH OF THE AREA. THE BEST CHANCES WILL BE IN THE
SOUTH OR SOUTHEAST TONIGHT. WILL HAVE TO WATCH THE SOUTHEAST...THIS
IS THE AREA WITH ONGOING FLOODING AND THE AREA THE MOST LIKELY TO
HAVE PRECIPITATION TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 318 AM CDT THU MAY 7 2015
GUIDANCE SUGGESTS AN UPPER TROPOSPHERIC LOW WILL EXIST OVER THE
SOUTHWESTERN CONUS TO START THE LONG-TERM FORECAST PERIOD AT 12Z
FRIDAY...WITH UPPER TROPOSPHERIC RIDGING OVER THE EASTERN CONUS.
THIS UPPER TROPOSPHERIC LOW IS EXPECTED TO MOVE NORTHEAST FRIDAY
THROUGH EARLY NEXT WEEK...LIKELY CLEARING THE CENTRAL PLAINS
SATURDAY INTO SUNDAY. QUASI-ZONAL UPPER TROPOSPHERIC FLOW IS THEN
EXPECTED ACROSS THE REGION DURING THE EARLY TO MIDDLE PART OF NEXT
WEEK.
GUIDANCE SUGGESTS UPPER TROPOSPHERIC THERMAL ADVECTION AHEAD OF THE
APPROACHING LOW WILL PROMOTE PRECIPITATION PRODUCTION ACROSS OUR AREA
FRIDAY THROUGH EARLY NEXT WEEK...WITH PERHAPS A RELATIVELY DRY
PERIOD AT SOME POINT EARLY NEXT WEEK AS THE AFOREMENTIONED UPPER
TROPOSPHERIC LOW CLEARS THE REGION. THAT SAID...GUIDANCE ALSO
SUGGESTS MULTIPLE UPPER TROPOSPHERIC PERTURBATIONS...EMBEDDED WITHIN
THE DEVELOPING QUASI-ZONAL FLOW...COULD PROMOTE ADDITIONAL
PRECIPITATION CHANCES DURING THE MIDDLE TO LATE PART OF NEXT WEEK.
GIVEN ALL THIS...POPS REMAIN INTACT ACROSS THE AREA DURING MUCH OF
THE LONG-TERM FORECAST PERIOD...WITH THE HIGHEST POPS EXISTING
BETWEEN SATURDAY AFTERNOON AND SATURDAY NIGHT AS THE UPPER
TROPOSPHERIC LOW CLEARS THE AREA.
A DRIER BOUNDARY-LAYER AIR MASS...ALONG WITH MODEST UPPER
TROPOSPHERIC LAPSE RATES...SHOULD KEEP SEVERE WEATHER AT BAY FRIDAY
INTO FRIDAY NIGHT...WITH GUIDANCE SUGGESTING POTENTIAL ENERGY WILL
REMAIN AT OR BELOW 500J/KG ACROSS MUCH OF THE CWA. THAT WILL CHANGE
FOR PORTIONS OF THE REGION SATURDAY INTO SATURDAY NIGHT HOWEVER AS
BOUNDARY-LAYER MOISTURE FLUX ACROSS THE CENTRAL PLAINS...ALONG WITH
INCREASING UPPER TROPOSPHERIC LAPSE RATES WITH THE APPROACH OF THE
UPPER TROPOSPHERIC LOW...PROMOTES POTENTIAL ENERGY ON THE ORDER OF
~1500J/KG ACROSS SOUTHERN PORTIONS OF THE CWA...AND LOWER POTENTIAL
ENERGY AS ONE MOVES NORTH ACROSS THE AREA. THESE POTENTIAL ENERGY
VALUES...WORKING IN CONCERT WITH DEEP-LAYER BULK SHEAR VALUES OF
AROUND 50KTS...COULD PRESENT YET ANOTHER OPPORTUNITY FOR SEVERE
WEATHER ACROSS PORTIONS OF THE CWA SATURDAY AFTERNOON INTO SATURDAY
NIGHT...ESPECIALLY ACROSS OUR SOUTHERN COUNTIES SOUTH OF HIGHWAY 6.
GIVEN THIS...WILL CONTINUE MENTIONING SEVERE WEATHER IN THE HWO
SATURDAY INTO SATURDAY NIGHT GENERALLY SOUTH OF HIGHWAY 6. DRIER
BOUNDARY-LAYER AIR AND DECREASING UPPER TROPOSPHERIC LAPSE RATES
SHOULD THEN ALLOW FOR A DECREASING SEVERE WEATHER THREAT AS WE MOVE
INTO THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1222 AM CDT THU MAY 7 2015
THE THUNDERSTORM ACTIVITY IS SOUTH OF THE TERMINAL AREAS AND
SHOULD STAY TO THE SOUTH. MID LEVEL CLOUDS WILL CONTINUE THROUGH
THE MORNING HOURS AND SHOULD START TO MOVE OUT DURING THE
AFTERNOON. A COLD FRONT WILL BE MOVING THROUGH THE AREA AND THE
WINDS SHOULD TURN FROM SOUTH TOWARD THE SOUTHWEST AND EVENTUALLY
TO THE NORTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1006 PM PDT WED MAY 6 2015
.SYNOPSIS...INCREASINGLY BREEZY CONDITIONS WILL DEVELOP THROUGH
THURSDAY AS A STRONG AND COLD LOW PRESSURE SYSTEM BEGINS TO MOVE
TOWARD SOUTHERN CALIFORNIA AND SOUTHERN NEVADA. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE AREA WIDE FRIDAY AS THE LOW MOVES OVER
THE REGION WITH TEMPERATURES WELL BELOW NORMAL. DRY AND WARMER
CONDITIONS ARE EXPECTED SUNDAY INTO EARLY NEXT WEEK.
&&
.UPDATE...WHAT IS LEFT OF A LINE OF SHOWERS (THAT EARLIER ALSO
CONTAINED THUNDERSTORMS) CONTINUES TO PROGRESS EAST THIS EVENING
ACROSS ESMERALDA AND CENTRAL NYE COUNTIES. HOWEVER, WITH THE LOSS OF
HEATING THIS ACTIVITY CONTINUES TO BE ON A DOWNWARD TREND. INFRARED
SATELLITE STILL SHOWS SOME BRIGHTER CLOUD TOPS SO A LIGHTNING STRIKE
OR TWO MAY STILL DEVELOP BUT BASED ON RECENT TRENDS THE FORECAST WAS
LEFT AS JUST SHOWERS FOR THE OVERNIGHT PERIOD. THE HRRR CONTINUES TO
SLOWLY WEAKEN THIS CONVECTION THROUGH THE REST OF THE NIGHT ACROSS
CENTRAL NYE COUNTY. THE GRIDS WERE UPDATED A BIT TO ACCOUNT FOR
RECENT AREAL COVERAGE TRENDS WITH THIS ACTIVITY, OTHERWISE NO OTHER
CHANGES WERE MADE TO THE ONGOING FORECAST.
&&
.AVIATION...FOR MCCARRAN...GUSTY SOUTH-SOUTHWEST WINDS AT TIMES TO
15-20 KTS ARE EXPECTED OVERNIGHT WITH SUSTAINED WINDS AVERAGING 8-12
KTS. SOUTH-SOUTHWEST WINDS AT 8-14 KTS IN THE MORNING WILL INCREASE
TO 15-20 KTS WITH GUSTS OF 25-30 KTS IN THE AFTERNOON AND EVENING.
CLEAR OVERNIGHT WITH SCT-BKN CLOUDS AOA 10-15K FEET ON THURSDAY
ESPECIALLY IN THE AFTERNOON AND EVENING. ISOLATED SHRA/TSRA POSSIBLE
AFTER 20Z THURSDAY THROUGH 04Z FRIDAY IN THE MOUNTAINS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...LINGERING SHRA AND CLOUD BASES TO 8K-12K FEET UNTIL
AROUND 08Z THURSDAY ACROSS ESMERALDA AND CENTRAL NYE COUNTIES.
OTHERWISE A CLEAR SKY OVERNIGHT WITH WINDS 6-12 KTS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS EXCEPT IN AND AROUND KDAG WHICH WILL STAY
SOUTHWEST TO WEST AT 15-25 KTS WITH GUSTS OF 20-30 KTS. WINDS WILL
INCREASE FROM THE SOUTH TO SOUTHWEST ACROSS THE AREA BY THURSDAY
AFTERNOON AND REMAIN GUSTY INTO THE EVENING WITH SPEEDS SUSTAINED AT
15-25 KTS WITH GUSTS OF 20-30 KTS EXCEPT IN AND AROUND KDAG WHERE
SUSTAINED WINDS OF 25-35 KTS WITH GUSTS OF 35-45 KTS POSSIBLE. LOCAL
AREAS OF BLDU MAY OCCUR REDUCING VSBY. OTHERWISE EXCEPT SCT-BKN
CLOUDS AOA 6K-12K FEET WITH SHRA/TSRA POSSIBLE ALONG AND NORTH OF
KEDW-KDRA-KIGM LINE. GUSTY AND ERRATIC WINDS POSSIBLE NEAR ANY
SHRA/TSRA OR OUTFLOW BOUNDARIES.
.PREV DISCUSSION... 247 PM PDT WED MAY 6 2015
.SHORT TERM...THROUGH FRIDAY NIGHT.
AS THE COLD CORE DIGS OVER CENTRAL CALIFORNIA THURSDAY...THIS WILL
PLACE INYO AND ESMERALDA COUNTIES CLOSE TO THE EASTERN SIDE OF THE
CORE THROUGH THURSDAY AFTERNOON THEN THE LOW CENTER IS FORECAST TO
TRACK DIRECTLY ACROSS THE SOUTHERN SIERRA AND OVER SOUTHERN NEVADA
FRIDAY. THIS WILL LEAD TO SIGNIFICANT SNOWFALL IN THE SOUTHERN
SIERRA AND A WINTER WEATHER ADVISORY HAS BEEN ISSUED ABOVE 6000
FEET. THE OTHER IMPACT OF THE SYSTEM WILL BE GUSTY SOUTH TO
SOUTHWEST WINDS ACROSS MUCH OF THE REGION THURSDAY AFTERNOON AND
EVENING. GUSTS OF 30 TO 40 MPH WILL BE COMMON BUT ADVISORY LEVEL
WINDS LOOK MARGINAL AND IT DOES NOT APPEAR TO HAVE THE POTENTIAL OF
PRODUCING WIDESPREAD BLOWING DUST SO NO WIND ADVISORIES ARE PLANNED
FOR NOW.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR ACROSS
THE REST OF THE REGION FRIDAY THROUGH FRIDAY EVENING BUT CONFIDENCE
IS LOW IN SIGNIFICANT SNOWFALL FOR THE SPRING MOUNTAINS SO NO OTHER
ADVISORIES ARE PLANNED FOR NOW. HIGH TEMPERATURES COULD BE THE
COOLEST SINCE EARLY MARCH WITH READINGS IN THE LOW TO MID 60S
EXPECTED IN LAS VEGAS FRIDAY.
.LONG TERM...SATURDAY THROUGH TUESDAY.
EVEN AS MAIN LOW SHIFTS EAST INTO THE FOUR CORNERS REGION SATURDAY,
MODELS INSIST ADDITIONAL ENERGY MOVING SOUTH WITHIN BACKSIDE OF
TROUGH WILL KEEP A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ACROSS
MAINLY SOUTHERN NEVADA AND INYO COUNTY SATURDAY. FOR SUNDAY, ANY
REMAINING INSTABILITY WILL CONFINE ISOLATED SHOWERS TO EASTERN
LINCOLN AND NORTHERN MOHAVE COUNTIES. DRY/STABLE AIR MASS ASSOCIATED
WITH RIDGING WILL START BUILDING IN FROM THE WEST. RIDGE QUICKLY
SHIFTS EAST MONDAY AS WINDS ALOFT BACK SOUTHWESTERLY ON TUESDAY
AHEAD OF NEXT TROUGH DEVELOPING NEAR THE PAC NW COAST. THERE IS SOME
SPREAD IN THE POSITIONING OF THIS NEXT TROUGH. AFTER THE DRAMATIC
COOL DOWN FRIDAY, TEMPERATURES WILL STEADILY WARM DURING THE PERIOD
RETURNING TO NORMAL OR SLIGHTLY ABOVE NORMAL MONDAY AND TUESDAY.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
AT THIS TIME HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS THIS WEEK ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
$$
UPDATE/AVIATION...STACHELSKI
SHORT TERM...ADAIR
LONG TERM...PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
623 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF CAPE FEAR MAY BECOME A SUBTROPICAL CYCLONE
OVER THE NEXT COUPLE OF DAYS. THE SYSTEM IS EXPECTED TO APPROACH
THE COAST OF SOUTH CAROLINA OR SOUTHERN NORTH CAROLINA FRIDAY AND
SATURDAY WITH INCREASING CHANCES FOR HEAVY RAIN...GUSTY WINDS...
AND DANGEROUS RIP CURRENTS AT THE BEACHES. THIS SYSTEM WILL ONLY
GRADUALLY LIFT NORTH AWAY FROM THE AREA EARLY NEXT WEEK. A COLD
FRONT WILL APPROACH NEXT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...BASED ON PROGRESS OF RAIN SHIELD WESTWARD
HAVE INCREASED POPS FURTHER THIS MORNING TO 100 PERCENT FOR THE
COASTAL AREAS FROM THE MYRTLES NORTHWARD. HAVE ALSO RAISED POPS
FOR OTHER AREAS FURTHER WESTWARDS. PREVIOUS DISCUSSION FOLLOWS:
EXTENSIVE RAIN SHIELD APPROACHING AND NOW SKIRTING THE COAST IS
HAVING TROUBLE HOLDING TOGETHER OVER LAND AS IT HAS TO OVERCOME A
VERY DRY MID LAYER. THE TEMP-DEWPOINT SPREAD AT THE 850 MB LEVEL
IS AROUND 45 DEGREES JUST INLAND OF THE COASTAL COUNTIES THIS
MORNING ACCORDING TO MODEL SOUNDINGS...SO ALTHOUGH THE BEACHES ARE
FINALLY SEEING SOME PATCHY LIGHT RAIN WITH CIGS AROUND 10
KFT...PROGRESS FURTHER WESTWARD WILL CONTINUE TO BE SLOW AND
UNEVEN. RADAR SHOWS A NARROW BAND OF HEAVIER RAIN ABOUT 20 NM
OFFSHORE. UNLESS THAT BAND GETS HERE INTACT WE CAN EXPECT ANY
ACCUMULATIONS TO BE ONLY ON THE VERY LIGHT SIDE THIS MORNING.
NHC NOW HAS THE NON-TROPICAL LOW PRESSURE SYSTEM AROUND 220 MILES
SSE OF THE SC/NC BORDER AND GIVES A 70 PERCENT CHANCE OF CYCLONE
FORMATION WITHIN 48 HOURS. SATELLITE LOOPS SHOW BETTER ORGANIZATION
AND A MORE DISTINCT CIRCULATION CENTER...WHICH IS BEING ANALYZED AT
AROUND 1009 MB. GUIDANCE IN REL GOOD AGREEMENT FOR THE NEAR TERM AS
FAR AS MOVEMENT GOES...WITH THE SYSTEM DRIFTING NW TOWARDS COASTAL
NC/SC. ALL MODELS SHOW DEEPENING WITH THE NAM BEING THE MOST
AGGRESSIVE. HAVE LEANED ON A BLEND OF GUIDANCE TO ACCOUNT FOR BOTH
THE UNCERTAINTY OF THE SITUATION AND AGREEMENT BETWEEN GUIDANCE.
EXPECT WINDS TO PICK UP FROM THE NE TODAY AS THE SYSTEM MOVES
NW...BUT THE RELATIVELY MODERATE ASSOCIATED GRADIENT WILL KEEP WINDS
IN THE 15 KT RANGE THIS AFTERNOON WITH GUSTS OF 20 KTS OR SO. PRECIP
WILL BE THE TRICKY ELEMENT OF THE FORECAST. GIVEN RECENT TRENDS AND
PROJECTED MOVEMENT OF THE SYSTEM HAVE UPPED POPS TO CATEGORICAL FOR
TODAY FOR THE COASTAL COUNTIES...TRENDING DOWNWARD AS ONE MOVES
INLAND. RETAINING POSSIBILITY OF THUNDER OVERNIGHT AS SYSTEM
APPROACHES THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...THE CHALLENGE...UNSURPRISINGLY...THROUGH
THE SHORT TERM REMAINS DETERMINING WHAT KIND OF IMPACT A
STRENGTHENING LOW PRESSURE WILL HAVE ON THE AREA. RECON FROM NHC
WAS CANCELLED YESTERDAY AFTN DUE TO LACK OF ORGANIZATION...AND
CURRENT WV/IR IMAGERY IS LESS THAN IMPRESSIVE...ALTHOUGH
IMPROVING. HOWEVER...GUIDANCE IS STARTING TO COME TO SOME GENERAL
CONSENSUS ON A SLOWER AND OVERALL WEAKER SYSTEM MEANDERING JUST
OFF THE COAST THROUGH THE PERIOD. LOW PRESSURE WILL LIFT NORTH TO
SOME WHERE JUST OFF THE SC COAST BEFORE THE PERIOD...AND THEN
STALL...LOOP...OR RETROGRADE BACK TOWARDS THE SW AS ITS MOTION
GETS HALTED BY RIDGE TO THE NORTH. VERY SLOW MOVEMENT IS EXPECTED
REGARDLESS OF THE ACTUAL TRACK...AND IT IS NEARLY GUARANTEED THAT
THIS WILL BE IMPACTING THE AREA ALL FRIDAY AND SATURDAY. A SLOWLY
LOOPING SYSTEM JUST OFFSHORE WILL MAINTAIN RAIN CHANCES...SOME OF
WHICH MAY BE HEAVY AT TIMES...THE CHANCE FOR SOME GUSTY WINDS
(FOCUSED ALMOST EXCLUSIVELY ALONG THE COAST HOWEVER)...AS WELL AS
HIGH WAVE ACTION/MINOR BEACH EROSION/STRONG RIP CURRENTS.
THE BIGGEST IMPACT LOCALLY IS LIKELY TO END UP BEING
RAINFALL...ESPECIALLY FROM MYRTLE BEACH NORTHWARD ACROSS THE CAPE
FEAR COAST. GUIDANCE SUGGESTING THAT 250MB DIFFLUENCE WILL BE ALMOST
EXCLUSIVELY ON THE N AND E SIDE OF THE SYSTEM (MORE EVIDENT IT WILL
NEVER TRULY BECOME TROPICAL EVEN AS FSU PHASE DIAGRAMS SUGGEST
SYMMETRIC WARM CORE DEVELOPMENT) WHICH SUGGESTS CONVECTION WILL BE
CONFINED TO THE N/E SIDE OF THE SYSTEM. WITH THE LOW STALLING JUST
SE OF THE AREA...COPIOUS MOISTURE WILL ADVECT FROM AN ANOMALOUSLY
HIGH PWAT AIRMASS...SO SOME VERY HEAVY RAIN WILL AT LEAST LURK
OFFSHORE...AND MAY ADVECT INLAND. A TIGHT AND SIGNIFICANT GRADIENT
WILL EXIST...AND CONVECTIVE ELEMENTS ARE POSSIBLE AS MOIST-ADIABATIC
LAPSE RATES EXIST DEEP INTO THE COLUMN. HIGHEST POP WILL REMAIN
FRIDAY ESP ALONG THE COAST...BUT A GOOD CHC FOR RAINFALL WILL
CONTINUE RIGHT TROUGH SATURDAY NIGHT.
TEMPS WILL STRUGGLE EVEN IN THE TROPICAL AIR MASS DUE TO WIDESPREAD
CLOUDS AND RAIN. HIGHS WILL REMAIN BELOW CLIMO...MID 70S FRIDAY AND
UPR 70S SATURDAY...BUT TEMPERED DIURNAL RANGES WILL KEEP MINS IN THE
UPR 60S OR CLOSE TO 70 BOTH NIGHTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...FIRST HALF OF THE EXTENDED WILL CONTINUE
TO FEATURE A SLOW MOVING LOW PRESSURE SYSTEM SOMEWHERE IN THE
VICINITY. THIS LOW PRESSURE WILL MEANDER JUST OFFSHORE OR POSSIBLY
JUST INLAND OF THE COAST SUNDAY AND MONDAY AS STEERING FLOW
REMAINS GENERALLY WEAK. WHILE A WEAKENING TREND IS EXPECTED DURING
THE LONG TERM...THE HIGHEST PWAT AIR MAY ACTUALLY MOVE ACROSS THE
CWA SUNDAY...SO PERIODS OF HEAVY RAINFALL COULD CONTINUE AT LEAST
INTO MONDAY. WILL NOT FOCUS ON ANY SPECIFICS AT THIS TIME
RANGE...AND JUST SHOW CONTINUED UNSETTLED WEATHER WITH CHC
POP...HIGHEST ACROSS THE CAPE FEAR REGION...WITH PERIODS OF MDT TO
POSSIBLY HVY RAINFALL. THE LOW WILL FINALLY KICK OUT TO THE NE ON
TUESDAY AS AN UPPER TROUGH DIGS INTO THE GREAT LAKES REGION. THE
UNSETTLED CONDITIONS WILL PERSIST INTO WEDNESDAY HOWEVER AS A COLD
FRONT DIGS ACROSS THE CAROLINAS AT THE END OF THE PERIOD. THERE IS
GOOD NEWS HOWEVER...AS THIS FRONT SHOULD BRING IN A PERIOD OF MUCH
DRIER CONDITIONS BEYOND THIS FORECAST PERIOD.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...CONFIDENCE IS STILL RATHER LOW...BUT IMPROVING AS THE
MODELS ARE STARTING TO GET A BIT MORE IN SYNC. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION TOWARD MORNING...WITH SHOWERS AND MVFR
CONDITIONS EXPECTED AN HOUR OR TWO AFTER DAYBREAK ALONG THE COAST.
AGAIN...THE UNCERTAINTY IS THERE AS THE HRRR MODEL IS SLOWER THAN
THIS. THE GRADIENT WILL TIGHTEN ALSO AROUND DAYBREAK...WITH GUSTS
OVER 20 KTS A GOOD BET AFTER 14Z. THE INLAND TERMINALS WILL TAKE A
WHILE TO GET ANY PRECIP...PERHAPS BY MID AFTERNOON. THE COLUMN OF
DEEP MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE
FORECAST PERIOD...WITH INTERMITTENT IFR POSSIBLE IN THE HEAVIER
PRECIP.
EXTENDED OUTLOOK...RAIN/MVFR. TEMPO IFR IN HEAVIER SHOWERS HIGHEST
CONFIDENCE COASTAL TERMINALS. BECOMING VFR/SHOWERS SUNDAY. VFR
ISOLATED SHOWERS MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH THE NEAR TERM AS A LOW
PRESSURE SYSTEM 220 MILES SSE OF THE NC/SC BORDER DRIFTS NW.
EXPECT WINDS AND SEAS TO BE HIGHEST OVER OUR SC WATERS...WITH 20
TO 25 KTS AND 5 TO 8 FT RESPECTIVELY FOR TODAY. CONDITIONS WILL BE
A BIT BETTER FOR OUR NC WATERS...BUT WILL STILL BE HAZARDOUS WITH
SEAS IN THE 5 TO 7 FT RANGE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...STRENGTHENING LOW PRESSURE WILL MEANDER
VERY NEAR THE COASTAL WATERS THROUGH THE ENTIRE PERIOD...CREATING
PERIODS OF GUSTY WINDS AND LARGE WAVES. WHILE UNCERTAINTY REMAINS
IN THE EXACT INTENSITY AND PLACEMENT OF THIS SYSTEM AS IT
EVOLVES...REGARDLESS OF THE EVENTUAL SOLUTION CONDITIONS WILL BE
DIFFICULT FOR MARINERS. WITH THE CURRENT FORECAST PATH EXPECTED TO
KEEP THE LOW CENTER EAST OF THE SC...WINDS WILL BE GENERALLY
EASTERLY ACROSS AMZ250 AND AMZ252...AND NORTHERLY OVER AMZ254 AND
AMZ256. THESE SHOULD REMAIN FAIRLY CONSISTENT THROUGH THE
PERIOD...ALTHOUGH SOME FLUCTUATION CAN BE EXPECTED...ESPECIALLY AS
THE LOW WOBBLES IN THE VICINITY. SPEEDS REGARDLESS OF DIRECTION
WILL BE 15-25 KTS...WITH SOME GUSTS OVER 30 KTS
POSSIBLE...PRIMARILY OVER THE NC WATERS.
WAVE HEIGHTS WILL BE HIGHEST ACROSS NC WATERS THANKS TO THE ONSHORE
FLOW WHERE 5-9 FT SEAS ARE EXPECTED FRIDAY. 4-7 FTERS ARE
ANTICIPATED ACROSS THE SC WATERS. SEAS WILL GRADUALLY START TO COME
DOWN THE LATTER HALF OF THE PERIOD BUT THIS WILL OBVIOUSLY DEPEND ON
EXACTLY HOW THE SYSTEM EVOLVES BEYOND FRIDAY. ATTM SHOW WAVE HEIGHTS
LOWERING TO 3-5 FT SATURDAY AND THE CURRENT SCA ENDING AT 8AM
SATURDAY ACROSS THE SOUTHERN WATERS. NC SEAS WILL LIKELY REMAIN
ELEVATED BEYOND THE 8AM SCA END-TIME BUT WILL EXTEND AS NEEDED WITH
FUTURE UPDATES.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...GUSTY WINDS TO START SUNDAY...ESPECIALLY
ACROSS THE NC WATERS...AS THE PERSISTENT LOW PRESSURE SYSTEM MOVES
SLOWLY NEAR THE AREA. ATTM THE BEST FORECAST TAKES THE LOW INLAND
ACROSS HORRY/BRUNSWICK COUNTIES...AND THUS WINDS THE FIRST HALF OF
SUNDAY WILL STILL BE GUSTY AROUND 20 KTS FROM THE EAST ACROSS
AMZ250/252...BUT MUCH WEAKER AND NORTHERLY OVER THE SC WATERS. THIS
SYSTEM WILL FINALLY BEGIN TO LIFT NE THROUGH SUNDAY AND INTO
MONDAY...SO WINDS WILL VEER TO THE SW AND BECOME 10-15 KTS ACROSS
ALL THE COASTAL WATERS. SEAS INITIALLY MAY STILL BE ABOVE SCA
THRESHOLDS ACROSS THE NC WATERS BUT SHOULD FALL THROUGH THE
DAY...AND 3-4 FT SEAS ARE FORECAST FOR MOST OF THE EXTENDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...DL
MARINE...REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
356 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF CAPE FEAR MAY BECOME A SUBTROPICAL CYCLONE
OVER THE NEXT COUPLE OF DAYS. THE SYSTEM IS EXPECTED TO APPROACH
THE COAST OF SOUTH CAROLINA OR SOUTHERN NORTH CAROLINA FRIDAY AND
SATURDAY WITH INCREASING CHANCES FOR HEAVY RAIN...GUSTY WINDS...
AND DANGEROUS RIP CURRENTS AT THE BEACHES. THIS SYSTEM WILL ONLY
GRADUALLY LIFT NORTH AWAY FROM THE AREA EARLY NEXT WEEK. A COLD
FRONT WILL APPROACH NEXT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...EXTENSIVE RAIN SHIELD APPROACHING AND NOW
SKIRTING THE COAST IS HAVING TROUBLE HOLDING TOGETHER OVER LAND AS
IT HAS TO OVERCOME A VERY DRY MID LAYER. THE TEMP-DEWPOINT SPREAD
AT THE 850 MB LEVEL IS AROUND 45 DEGREES JUST INLAND OF THE
COASTAL COUNTIES THIS MORNING ACCORDING TO MODEL SOUNDINGS...SO
ALTHOUGH THE BEACHES ARE FINALLY SEEING SOME PATCHY LIGHT RAIN
WITH CIGS AROUND 10 KFT...PROGRESS FURTHER WESTWARD WILL CONTINUE
TO BE SLOW AND UNEVEN. RADAR SHOWS A NARROW BAND OF HEAVIER RAIN
ABOUT 20 NM OFFSHORE. UNLESS THAT BAND GETS HERE INTACT WE CAN
EXPECT ANY ACCUMULATIONS TO BE ONLY ON THE VERY LIGHT SIDE THIS
MORNING.
NHC NOW HAS THE NON-TROPICAL LOW PRESSURE SYSTEM AROUND 220 MILES
SSE OF THE SC/NC BORDER AND GIVES A 70 PERCENT CHANCE OF CYCLONE
FORMATION WITHIN 48 HOURS. SATELLITE LOOPS SHOW BETTER ORGANIZATION
AND A MORE DISTINCT CIRCULATION CENTER...WHICH IS BEING ANALYZED AT
AROUND 1009 MB. GUIDANCE IN REL GOOD AGREEMENT FOR THE NEAR TERM AS
FAR AS MOVEMENT GOES...WITH THE SYSTEM DRIFTING NW TOWARDS COASTAL
NC/SC. ALL MODELS SHOW DEEPENING WITH THE NAM BEING THE MOST
AGGRESSIVE. HAVE LEANED ON A BLEND OF GUIDANCE TO ACCOUNT FOR BOTH
THE UNCERTAINTY OF THE SITUATION AND AGREEMENT BETWEEN GUIDANCE.
EXPECT WINDS TO PICK UP FROM THE NE TODAY AS THE SYSTEM MOVES
NW...BUT THE RELATIVELY MODERATE ASSOCIATED GRADIENT WILL KEEP WINDS
IN THE 15 KT RANGE THIS AFTERNOON WITH GUSTS OF 20 KTS OR SO. PRECIP
WILL BE THE TRICKY ELEMENT OF THE FORECAST. GIVEN RECENT TRENDS AND
PROJECTED MOVEMENT OF THE SYSTEM HAVE UPPED POPS TO CATEGORICAL FOR
TODAY FOR THE COASTAL COUNTIES...TRENDING DOWNWARD AS ONE MOVES
INLAND. RETAINING POSSIBILITY OF THUNDER OVERNIGHT AS SYSTEM
APPROACHES THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...THE CHALLENGE...UNSURPRISINGLY...THROUGH
THE SHORT TERM REMAINS DETERMINING WHAT KIND OF IMPACT A
STRENGTHENING LOW PRESSURE WILL HAVE ON THE AREA. RECON FROM NHC
WAS CANCELLED YESTERDAY AFTN DUE TO LACK OF ORGANIZATION...AND
CURRENT WV/IR IMAGERY IS LESS THAN IMPRESSIVE...ALTHOUGH
IMPROVING. HOWEVER...GUIDANCE IS STARTING TO COME TO SOME GENERAL
CONSENSUS ON A SLOWER AND OVERALL WEAKER SYSTEM MEANDERING JUST
OFF THE COAST THROUGH THE PERIOD. LOW PRESSURE WILL LIFT NORTH TO
SOME WHERE JUST OFF THE SC COAST BEFORE THE PERIOD...AND THEN
STALL...LOOP...OR RETROGRADE BACK TOWARDS THE SW AS ITS MOTION
GETS HALTED BY RIDGE TO THE NORTH. VERY SLOW MOVEMENT IS EXPECTED
REGARDLESS OF THE ACTUAL TRACK...AND IT IS NEARLY GUARANTEED THAT
THIS WILL BE IMPACTING THE AREA ALL FRIDAY AND SATURDAY. A SLOWLY
LOOPING SYSTEM JUST OFFSHORE WILL MAINTAIN RAIN CHANCES...SOME OF
WHICH MAY BE HEAVY AT TIMES...THE CHANCE FOR SOME GUSTY WINDS
(FOCUSED ALMOST EXCLUSIVELY ALONG THE COAST HOWEVER)...AS WELL AS
HIGH WAVE ACTION/MINOR BEACH EROSION/STRONG RIP CURRENTS.
THE BIGGEST IMPACT LOCALLY IS LIKELY TO END UP BEING
RAINFALL...ESPECIALLY FROM MYRTLE BEACH NORTHWARD ACROSS THE CAPE
FEAR COAST. GUIDANCE SUGGESTING THAT 250MB DIFFLUENCE WILL BE ALMOST
EXCLUSIVELY ON THE N AND E SIDE OF THE SYSTEM (MORE EVIDENT IT WILL
NEVER TRULY BECOME TROPICAL EVEN AS FSU PHASE DIAGRAMS SUGGEST
SYMMETRIC WARM CORE DEVELOPMENT) WHICH SUGGESTS CONVECTION WILL BE
CONFINED TO THE N/E SIDE OF THE SYSTEM. WITH THE LOW STALLING JUST
SE OF THE AREA...COPIOUS MOISTURE WILL ADVECT FROM AN ANOMALOUSLY
HIGH PWAT AIRMASS...SO SOME VERY HEAVY RAIN WILL AT LEAST LURK
OFFSHORE...AND MAY ADVECT INLAND. A TIGHT AND SIGNIFICANT GRADIENT
WILL EXIST...AND CONVECTIVE ELEMENTS ARE POSSIBLE AS MOIST-ADIABATIC
LAPSE RATES EXIST DEEP INTO THE COLUMN. HIGHEST POP WILL REMAIN
FRIDAY ESP ALONG THE COAST...BUT A GOOD CHC FOR RAINFALL WILL
CONTINUE RIGHT TROUGH SATURDAY NIGHT.
TEMPS WILL STRUGGLE EVEN IN THE TROPICAL AIR MASS DUE TO WIDESPREAD
CLOUDS AND RAIN. HIGHS WILL REMAIN BELOW CLIMO...MID 70S FRIDAY AND
UPR 70S SATURDAY...BUT TEMPERED DIURNAL RANGES WILL KEEP MINS IN THE
UPR 60S OR CLOSE TO 70 BOTH NIGHTS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...FIRST HALF OF THE EXTENDED WILL CONTINUE
TO FEATURE A SLOW MOVING LOW PRESSURE SYSTEM SOMEWHERE IN THE
VICINITY. THIS LOW PRESSURE WILL MEANDER JUST OFFSHORE OR POSSIBLY
JUST INLAND OF THE COAST SUNDAY AND MONDAY AS STEERING FLOW
REMAINS GENERALLY WEAK. WHILE A WEAKENING TREND IS EXPECTED DURING
THE LONG TERM...THE HIGHEST PWAT AIR MAY ACTUALLY MOVE ACROSS THE
CWA SUNDAY...SO PERIODS OF HEAVY RAINFALL COULD CONTINUE AT LEAST
INTO MONDAY. WILL NOT FOCUS ON ANY SPECIFICS AT THIS TIME
RANGE...AND JUST SHOW CONTINUED UNSETTLED WEATHER WITH CHC
POP...HIGHEST ACROSS THE CAPE FEAR REGION...WITH PERIODS OF MDT TO
POSSIBLY HVY RAINFALL. THE LOW WILL FINALLY KICK OUT TO THE NE ON
TUESDAY AS AN UPPER TROUGH DIGS INTO THE GREAT LAKES REGION. THE
UNSETTLED CONDITIONS WILL PERSIST INTO WEDNESDAY HOWEVER AS A COLD
FRONT DIGS ACROSS THE CAROLINAS AT THE END OF THE PERIOD. THERE IS
GOOD NEWS HOWEVER...AS THIS FRONT SHOULD BRING IN A PERIOD OF MUCH
DRIER CONDITIONS BEYOND THIS FORECAST PERIOD.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...CONFIDENCE IS STILL RATHER LOW...BUT IMPROVING AS THE
MODELS ARE STARTING TO GET A BIT MORE IN SYNC. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION TOWARD MORNING...WITH SHOWERS AND MVFR
CONDITIONS EXPECTED AN HOUR OR TWO AFTER DAYBREAK ALONG THE COAST.
AGAIN...THE UNCERTAINTY IS THERE AS THE HRRR MODEL IS SLOWER THAN
THIS. THE GRADIENT WILL TIGHTEN ALSO AROUND DAYBREAK...WITH GUSTS
OVER 20 KTS A GOOD BET AFTER 14Z. THE INLAND TERMINALS WILL TAKE A
WHILE TO GET ANY PRECIP...PERHAPS BY MID AFTERNOON. THE COLUMN OF
DEEP MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE
FORECAST PERIOD...WITH INTERMITTENT IFR POSSIBLE IN THE HEAVIER
PRECIP.
EXTENDED OUTLOOK...RAIN/MVFR. TEMPO IFR IN HEAVIER SHOWERS HIGHEST
CONFIDENCE COASTAL TERMINALS. BECOMING VFR/SHOWERS SUNDAY. VFR
ISOLATED SHOWERS MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...SMALL CRAFT ADVISORY WILL CONTINUE
THROUGH THE NEAR TERM AS A LOW PRESSURE SYSTEM 220 MILES SSE OF
THE NC/SC BORDER DRIFTS NW. EXPECT WINDS AND SEAS TO BE HIGHEST
OVER OUR SC WATERS...WITH 20 TO 25 KTS AND 5 TO 8 FT RESPECTIVELY
FOR TODAY. CONDITIONS WILL BE A BIT BETTER FOR OUR NC WATERS...BUT
WILL STILL BE HAZARDOUS WITH SEAS IN THE 5 TO 7 FT RANGE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...STRENGTHENING LOW PRESSURE WILL MEANDER
VERY NEAR THE COASTAL WATERS THROUGH THE ENTIRE PERIOD...CREATING
PERIODS OF GUSTY WINDS AND LARGE WAVES. WHILE UNCERTAINTY REMAINS
IN THE EXACT INTENSITY AND PLACEMENT OF THIS SYSTEM AS IT
EVOLVES...REGARDLESS OF THE EVENTUAL SOLUTION CONDITIONS WILL BE
DIFFICULT FOR MARINERS. WITH THE CURRENT FORECAST PATH EXPECTED TO
KEEP THE LOW CENTER EAST OF THE SC...WINDS WILL BE GENERALLY
EASTERLY ACROSS AMZ250 AND AMZ252...AND NORTHERLY OVER AMZ254 AND
AMZ256. THESE SHOULD REMAIN FAIRLY CONSISTENT THROUGH THE
PERIOD...ALTHOUGH SOME FLUCTUATION CAN BE EXPECTED...ESPECIALLY AS
THE LOW WOBBLES IN THE VICINITY. SPEEDS REGARDLESS OF DIRECTION
WILL BE 15-25 KTS...WITH SOME GUSTS OVER 30 KTS
POSSIBLE...PRIMARILY OVER THE NC WATERS.
WAVE HEIGHTS WILL BE HIGHEST ACROSS NC WATERS THANKS TO THE ONSHORE
FLOW WHERE 5-9 FT SEAS ARE EXPECTED FRIDAY. 4-7 FTERS ARE
ANTICIPATED ACROSS THE SC WATERS. SEAS WILL GRADUALLY START TO COME
DOWN THE LATTER HALF OF THE PERIOD BUT THIS WILL OBVIOUSLY DEPEND ON
EXACTLY HOW THE SYSTEM EVOLVES BEYOND FRIDAY. ATTM SHOW WAVE HEIGHTS
LOWERING TO 3-5 FT SATURDAY AND THE CURRENT SCA ENDING AT 8AM
SATURDAY ACROSS THE SOUTHERN WATERS. NC SEAS WILL LIKELY REMAIN
ELEVATED BEYOND THE 8AM SCA END-TIME BUT WILL EXTEND AS NEEDED WITH
FUTURE UPDATES.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...GUSTY WINDS TO START SUNDAY...ESPECIALLY
ACROSS THE NC WATERS...AS THE PERSISTENT LOW PRESSURE SYSTEM MOVES
SLOWLY NEAR THE AREA. ATTM THE BEST FORECAST TAKES THE LOW INLAND
ACROSS HORRY/BRUNSWICK COUNTIES...AND THUS WINDS THE FIRST HALF OF
SUNDAY WILL STILL BE GUSTY AROUND 20 KTS FROM THE EAST ACROSS
AMZ250/252...BUT MUCH WEAKER AND NORTHERLY OVER THE SC WATERS. THIS
SYSTEM WILL FINALLY BEGIN TO LIFT NE THROUGH SUNDAY AND INTO
MONDAY...SO WINDS WILL VEER TO THE SW AND BECOME 10-15 KTS ACROSS
ALL THE COASTAL WATERS. SEAS INITIALLY MAY STILL BE ABOVE SCA
THRESHOLDS ACROSS THE NC WATERS BUT SHOULD FALL THROUGH THE
DAY...AND 3-4 FT SEAS ARE FORECAST FOR MOST OF THE EXTENDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...REK
MARINE...REK/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
123 AM EDT THU MAY 7 2015
.SYNOPSIS...
LOW PRESSURE SOUTH OF CAPE FEAR MAY BECOME A SUBTROPICAL CYCLONE
OVER THE NEXT COUPLE OF DAYS. THE SYSTEM IS EXPECTED TO APPROACH
THE COAST OF SOUTH CAROLINA OR SOUTHERN NORTH CAROLINA FRIDAY AND
SATURDAY WITH INCREASING CHANCES FOR HEAVY RAIN...GUSTY WINDS...
AND DANGEROUS RIP CURRENTS AT THE BEACHES. UNSETTLED WEATHER
SHOULD PERSIST INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:30 AM THURSDAY...BASED ON MOVEMENT OF PRECIP SHIELD AND
LATEST DATA HAVE SUBSTANTIALLY RAISED POPS FOR TODAY TO
CATEGORICAL FOR ALONG THE COAST. WILL ALSO LIKELY SPEED UP
WESTWARD PROGRESSION OF PRECIP FOR THE EARLY MORNING HOURS. FINAL
CUT FOR TODAYS RAIN EVENT NOT IN YET THOUGH...STILL TWEAKING
TIMING AND QPF AMOUNTS. DISCUSSION FROM 730 PM FOLLOWS...
THE LOW SEVERAL HUNDRED MILES SOUTH OF CAPE FEAR HAS CHANGED
LITTLE IN ORGANIZATION THIS AFTERNOON. THE LATEST WORD FROM THE
HURRICANE CENTER IS STILL FOR A 60 PERCENT CHANCE OF DEVELOPMENT
INTO A NAMED SUBTROPICAL STORM OVER THE NEXT FEW DAYS. THE NASA
GLOBAL PRECIPITATION MISSION (GPM) SATELLITE OVERFLEW THE SYSTEM
EARLY THIS AFTERNOON AND SHOWED RAINFALL ECHOES LARGELY DISLOCATED
FROM THE SATELLITE-INFERRED CIRCULATION CENTER. (SEE OUR LATEST
FACEBOOK/TWITTER POSTS) THIS DOES NOT BODE WELL FOR RAPID
STRENGTHENING...ALTHOUGH THIS COULD CHANGE AS THE SYSTEM REMAINS
NEAR THE WARM GULF STREAM CURRENT FOR AT LEAST ANOTHER 36 HOURS.
DENSE CIRRUS ALONG THE COAST SHOULD CONTINUE OVERNIGHT AS THE
UPPER LOW OFFSHORE MAINTAINS A SOUTHERLY FLOW AT 200-300 MB.
MOISTURE AT 700 MB IS REMAINING 50+ MILES OFFSHORE WITH RATHER DRY
AIR ACROSS THE EASTERN CAROLINAS AT THIS TIME. AS WINDS THROUGHOUT
THIS LEVEL TURN MORE EASTERLY TONIGHT THE LARGE SHIELD OF RAIN
VISIBLE ON THE PERIPHERY OF OUR RADAR SHOULD SHIFT
WESTWARD. I HAVE SLOWED DOWN THE WESTWARD ADVANCE OF
PRECIPITATION FROM PREVIOUS FORECASTS A BIT...WITH CHANCES OF
MEASURABLE RAIN BY DAYBREAK 30-50 PERCENT AT THE COAST AND 10
PERCENT OR LESS ALONG I-95. NO SIGNIFICANT CHANGES HAVE BEEN MADE
TO LOWS...STILL EXPECTED TO RANGE FROM THE UPPER 50S INLAND TO THE
LOWER 60S AT THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...A LARGE SWATCH OF SHOWERS AND THUNDERSTORMS
OFF THE FLORIDA EAST COAST AND IN THE VICINITY OF THE BAHAMAS HAS
BEEN RELUCTANT TO BECOME MUCH MORE ORGANIZED TODAY. THE NATIONAL
HURRICANE CENTER CONTINUES TO MONITOR AND MAY SEND A PLANE INTO
THE SYSTEM ON THURSDAY TO BETTER EVALUATE ITS STRUCTURE AND
INTENSITY. MODELS ARE RATHER CONSISTENT IN SHOWING A VERY SLOW
EVOLUTION AS THE SHOWERS AND THUNDERSTORMS CONTINUE TO ADVANCE/
EXPAND FURTHER NORTH ACROSS THE EASTERN CAROLINAS. HAVE INCLUDED
LIKELY TO WIDESPREAD CONVECTION FOR MUCH OF THE PERIOD. THE
PERSISTENCE OF THE RAINFALL MAY LEAD TO A RISK FOR SIGNIFICANT
PONDING AND PERHAPS SOME FLOODING. AT THIS TIME...IT IS DIFFICULT
TO PINPOINT WHERE THE HEAVIEST OF RAIN WILL FALL. CERTAINLY THERE
WILL BE PLENTY OF VERY HEAVY RAINFALL OFFSHORE. IF DEVELOPING LOW
PRESSURE IS ABLE TO DRIFT OR REDEVELOP WESTWARD AND CLOSER TO THE
COAST...THEN THE RISK FOR EXCESSIVE RAINFALL WILL MOVE ACROSS THE
EASTERN CAROLINAS. AT THIS TIME...RAINFALL AMOUNTS UP TO 1 TO 2
INCHES IS CERTAINLY POSSIBLE WITH AGAIN A POTENTIAL FOR MUCH
HIGHER AMOUNTS. THE COASTAL AREAS SHOULD BE PRONE TO THE HIGHER
RAINFALL TOTALS. OTHERWISE...GUSTY WINDS ARE EXPECTED WITH THE
STRONGEST WINDS NOW EXPECTED ON FRI...UP TO 20 TO 30 MPH AND FROM
THE NE. THE SURF ZONE WILL LIKELY BECOME DANGEROUS WITH BUILDING
BREAKERS...ROUGH SURF...STRONG RIP CURRENTS AND SIGNIFICANT BEACH
EROSION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...SYSTEM STILL SLOW TO ORGANIZE TODAY OFF THE
SOUTHEAST COAST. SO SLOW IN FACT THAT THE RECON HAS BEEN POSTPONED.
UNTIL THIS SYSTEM BEGINS TO CONGEAL (AT WHICH TIME AIRCRAFT RECON
WILL BECOME LIKELY) ITS STILL VERY TOUGH TO ASCERTAIN HOW THINGS
WILL PAN OUT. IN THE VERY NEAR TERM THE SOUTHERN CENTER JUST NORTH
OF THE BAHAMAS SEEMS TO BE WEAKENING IN FAVOR OF THE NORTHERN CENTER
ROUGHLY EAST OF JACKSONVILLE, FL. THE FORMER IS A WEAK REFLECTION OF
THE UPPER LOW WHILE THE LATTER IS THE MORE TYPICAL FRONTAL LOW. MOST
MODELS INDICATE THAT THE FRONTAL LOW REMAINS DOMINANT AND THAT THE
FRONTAL STRUCTURE WEAKENS AS THE SYSTEM MOVES SLOWLY TO THE NORTH.
THIS CONTINUES TO BE SUPPORTED BY THE FLORIDA STATE CYCLONE PHASE
DIAGRAMS THAT EVENTUALLY INDICATE A WEAKLY WARM CORE SYMMETRIC
SYSTEM. SSTS ARE MARGINAL TO SAY THE LEAST SO A HYBRID SYSTEM
APPEARS MORE LIKELY THAN PURELY TROPICAL BUT IN THE END NHC WILL
HAVE THAT CALL. LOCALLY THE CHANCE FOR HEAVY RAINFALL SEEMS TO BE
GOING UP MORE NOTABLY THAN THE CHANCE FOR ANY MEMORABLE WINDS.
ASSUMING AT LEAST SOME WARM RAIN PROCESSES THE TRACK OF THIS SYSTEM
(IT WILL BE A VERY SLOW MOVER AND MAY EVEN STALL, LOOP, OR
RETROGRADE) WE COULD SEE ANYTHING FROM A BENEFICIALLY VERY WET
WEEKEND TO SOME ARRANT FLOODING ISSUES. ANOTHER FACTOR THAT
COMPLICATES THE RAINFALL POTENTIAL IS THE SEEMING LIKELIHOOD OF A
HYBRID SYSTEM. THE RAINFALL DISTRIBUTION WILL NOT BE VERY SYMMETRICAL
ABOUT THE CIRCULATION. RATHER, THERE SHOULD BE A FOCUSED CHANNEL OF
SOUTHEASTERLY FLOW WHERE A FAIRLY LOCALIZED BULLSEYE OF HEAVY
RAINFALL IS FOCUSED. GIVEN THE AFOREMENTIONED POSSIBILITY OF A
STALLED OUT SYSTEM THE POP FORECAST WILL ONLY GRADUALLY DECREASE
HEADING INTO EARLY NEXT WEEK. MOISTURE FROM THIS SYSTEM COULD
CONCEIVABLY LINGER INTO TUESDAY OR WEDNESDAY AT WHICH TIME A COLD
FRONT WILL BE APPROACHING FROM THE NORTHWEST.
&&
.AVIATION /06Z WEDNESDAY THROUGH MONDAY/...
AS OF 06Z...CONFIDENCE IS STILL RATHER LOW...BUT IMPROVING AS THE
MODELS ARE STARTING TO GET A BIT MORE IN SYNC. LOW PRESSURE WILL
SLOWLY APPROACH THE REGION TOWARD MORNING...WITH SHOWERS AND MVFR
CONDITIONS EXPECTED AN HOUR OR TWO AFTER DAYBREAK ALONG THE COAST.
AGAIN...THE UNCERTAINTY IS THERE AS THE HRRR MODEL IS SLOWER THAN
THIS. THE GRADIENT WILL TIGHTEN ALSO AROUND DAYBREAK...WITH GUSTS
OVER 20 KTS A GOOD BET AFTER 14Z. THE INLAND TERMINALS WILL TAKE A
WHILE TO GET ANY PRECIP...PERHAPS BY MID AFTERNOON. THE COLUMN OF
DEEP MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE
FORECAST PERIOD...WITH INTERMITTENT IFR POSSIBLE IN THE HEAVIER
PRECIP.
EXTENDED OUTLOOK...RAIN/MVFR. TEMPO IFR IN HEAVIER SHOWERS HIGHEST
CONFIDENCE COASTAL TERMINALS. BECOMING VFR/SHOWERS SUNDAY. VFR
ISOLATED SHOWERS MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LOW PRESSURE A FEW HUNDRED MILES SOUTH OF CAPE FEAR IS NOT
BECOMING APPRECIABLY BETTER ORGANIZED THIS EVENING...BUT CONTINUES
TO HAVE A BETTER THAN A 50-50 CHANCE OF BECOMING A NAMED
SUBTROPICAL CYCLONE IN THE NEXT FEW DAYS. REGARDLESS OF ITS
DESIGNATION...A LARGE COUNTERCLOCKWISE SWIRL OF WINDS FROM CAPE
HATTERAS INTO THE NORTHERN BAHAMAS IS BUILDING SEA HEIGHTS AT A
PRETTY GOOD RATE EARLY THIS EVENING. DATA FROM THE FRYING PAN
SHOALS BUOY INDICATES SEAS ARE ALREADY 7.2 FEET...WITH 4.5-5 FOOT
SEAS SHOWING UP VERY CLOSE TO SHORE AT THE TWO CORMP BUOYS NEAR
CAPE FEAR.
RADAR SHOWS RAIN OFFSHORE ON THE NORTHERN PERIPHERY OF THE CYCLONE
HAS PUSHED UP TO ABOUT 20 MILES FROM CAPE FEAR. RELATIVELY DRY
AIR SHOULD IMPEDE THIS RAIN FROM MOVING WESTWARD TOO RAPIDLY...BUT
SHOWERS SHOULD BE LIKELY ACROSS MOST OF THE WATERS BY DAYBREAK.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 PM WEDNESDAY...SMALL CRAFT ADVISORY FLAGS WILL BE FLYING
THROUGH THE PERIOD. HOWEVER...THESE FLAGS MAY BE REPLACED BY A
TROPICAL STORM WATCH OR WARNING DURING/BY THURSDAY. IN EITHER
CASE...THE SLOW EVOLUTION AND MOVEMENT OF THIS SYSTEM UP THE
SOUTHEAST COAST AND ITS EXPANSIVE CONVECTION WILL CHURN UP SEAS
AND WE ARE EXPECTING SEAS TO BUILD UP TO 6 TO 10 FT...PERHAPS
PEAKING THU NIGHT AND FRI. WIND SPEEDS WILL BE UP TO 20 TO 30 KT
WITH HIGHER GUSTS AND THE DIRECTION WILL PRIMARILY BE FROM THE NE
AND E THU AND THU NIGHT AND E OR SE FRI AND FRI NIGHT.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 300 PM WEDNESDAY...WE WILL HAVE ADVISORIES UP ON SATURDAY
IF NOT TROPICAL WARNINGS FROM NHC. THE POSSIBLE SLOW AND ERRATIC
MOVEMENT OF THE SYSTEM WILL MAKE IT TOUGH TO SAY AT WHAT SPEED
CONDITIONS WILL IMPROVE AND AT WHAT TIME SUCH HEADLINES CAN BE
STEPPED DOWN. A STALLING OF THE STORM COULD ALSO MEAN THAT THE
WIND DIRECTION FORECAST IS OFF. IN THE END UNTIL THIS SYSTEM
STARTS TO CONGEAL INTO A MORE ORGANIZED AREA OF LOW PRESSURE
(TOMORROW OR FRIDAY) THERE IS JUST TOO MUCH UNCERTAINTY TO CHANGE
THE FORECAST MUCH AT ALL AT THIS TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT FRIDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...RJD
NEAR TERM...REK/TRA
SHORT TERM...RJD
LONG TERM...MBB
AVIATION...DL
MARINE...REK/RJD/TRA/MBB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1007 PM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 1005 PM CDT FRI MAY 8 2015
WELL...CLOUD TRENDS FROM 23Z HRRR NOT WORKING OUT EXACTLY HAS HAVE
SEEN LARGER HOLES NOW FORM FROM HALLOCK TO CROOKSTON AND IN THE
WARROAD AREA. ALSO CLEARING AREA IN WCNTRL MN HAS PUSHED WEST INTO
FARGO. THUS RE-DID SOME CLOUD TRENDS IN THE GRIDS FOR A BIT MORE
CLEARING IN NW MN. STILL THINK WEST OF THE RRV IS BEST BET FOR
CLOUDS ALL NIGHT. WITH CLEARING TRENDS DID LOWER TEMPS A TAD AS
ROSEAU AND WARROAD AT 30F ALREADY. A FEW UPPER 20S SEEM REASONABLE
IN CLEARER AREA. BUT WITH MUCH UNCERTAINITY IN CLOUD TRENDS UNSURE
HOW LONG IT WILL REMAIN IN THE UPPER 20S IN AREA THAT GET DOWN
THAT LOW. SO WILL HOLD ON TO FROST ADV.
&&
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 715 PM CDT FRI MAY 8 2015
USED 23Z HRRR AS A GUIDE FOR THE TAFS. IT KEEPS GENERAL MVFR CIGS
OVER ERN ND THRU THE NIGHT...PERHAPS RISING A BIT INTO VFR RANGE
LATER TONIGHT INTO SATURDAY. CLEARING THAT WORKED INTO BEMIDJI MAY
BECOME MORE MVFR CIG DECK TONIGHT. CLEARING/CLOUD LINE RIGHT OVER
THEM NOW. ADJUSTMENTS WILL BE MADE IF ABOVE IDEAS DONT WORK OUT.
&&
.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 GRAND FORKS ND
720 PM CDT FRI MAY 8 2015
.UPDATE...
ISSUED AT 715 PM CDT FRI MAY 8 2015
23Z HRRR HAD A GOOD HANDLE ON LOW CLOUD AREA....AS IT HAD THE
CLEARING AREA IN CENTRAL/NORTH CENTRAL/WEST CENTRAL MN AND THE
SOLID CLOUDS OVER ERN/NCNTRL ND INTO FAR NRN MN/SOUTHERN MANITOBA.
IT SHOWS LITTLE CHANGE OVERNIGHT WITH THE CLOUD COVER IN ERN ND
AND HAS THE CLOUDS IN NRN MN SINKING SOUTH A BIT. USED THIS
THINKING IN UPDATED SKY COVER GRIDS AND AVIATION. EVEN WITH
CLOUDS ENOUGH COLD AIR TO HAVE LOWS IN MOST AREAS 32-35
RANGE...WITH SOME COLDER SPOTS IN NE ND EVEN WITH CLOUDS. CLEAR
AREA IN SOUTHEASTERN FCST AREA HAS A GOOD CHC OF 32-34 AS WELL.
FROST PER SE MAY NOT OCCUR IN MOST AREAS DUE TO CLOUDS....BUT
TEMPS COLD ENOUGH THAT SOME TENDER VEGETATION MAY HAVE ISSUES.
WILL KEEP HEADLINES.
&&
.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 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 715 PM CDT FRI MAY 8 2015
USED 23Z HRRR AS A GUIDE FOR THE TAFS. IT KEEPS GENERAL MVFR CIGS
OVER ERN ND THRU THE NIGHT...PERHAPS RISING A BIT INTO VFR RANGE
LATER TONIGHT INTO SATURDAY. CLEARING THAT WORKED INTO BEMIDJI MAY
BECOME MORE MVFR CIG DECK TONIGHT. CLEARING/CLOUD LINE RIGHT OVER
THEM NOW. ADJUSTMENTS WILL BE MADE IF ABOVE IDEAS DONT WORK OUT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FROST ADVISORY FROM 1 AM TO 9 AM CDT SATURDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...FROST ADVISORY FROM 1 AM TO 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 BISMARCK ND
1236 PM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1231 PM CDT THU MAY 7 2015
SHOWERS CONTINUE TO DIMINISH ACROSS THE AREA AS UPPER LOW LIFTS TO
THE NORTHEAST. FOR EARLY AFTERNOON UPDATE WILL TAPER OFF
PRECIPITATION CHANCES ON THE WEST SIDE OF THE SYSTEM. HAVE ALSO
DROPPED HIGH TEMPERATURES A BIT WITH THE COOL AIRMASS MOVING IN
BEHIND THE FRONT. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 847 AM CDT THU MAY 7 2015
SHOWER ACTIVITY CONTINUES TO SLOWLY ERODE ON THE WEST
SIDE...THOUGH THIS IS OCCURRING A BIT SLOWER THAN PREVIOUS
FORECAST. THEREFORE...HAVE INCREASED POPS A BIT THROUGH MID DAY.
COLD FRONT HAS PUSHED THROUGH CENTRAL NORTH DAKOTA...AND IS SLOWLY
EXITING THE EASTERN JAMES RIVER VALLEY. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE OBSERVATIONS PORTRAYING GUSTY NORTHWEST WINDS BETWEEN 25
AND 40 MPH BEHIND THE COLD FRONT. SURFACE COLD FRONT NOW MOVING
INTO JAMESTOWN AND SOUTH INTO OAKES.HAVE INCREASED WINDS CLOSER
TO THE 06Z MAV GUIDANCE THROUGH THE AFTERNOON. NEAR WIND ADVISORY
CRITERIA IN SOME SPOTS CURRENTLY...BUT WILL HOLD OFF AS UPSTREAM
WINDS IN SOUTHERN SASKATCHEWAN ARE MORE IN THE 20 TO 30 MPH RANGE.
LATEST RADAR AND WATER VAPOR IMAGERY DEPICT THE MID/UPPER LEVEL
LOW NOW CIRCULATING OVER THE SOUTHERN JAMES RIVER VALLEY. RADAR
RETURNS SLOWLY WEAKENING WEST OF BISMARCK AND THE CURRENT GRIDDED
FORECAST HAS THE POPS DIMINISHING FROM WEST TO EAST...WHICH IS ON
TRACK. BISMARCK ASOS TOTAL PRECIPITATION LAST 24HOURS HAS BEEN
0.72 INCHES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1231 PM CDT THU MAY 7 2015
WIDESPREAD MVFR CIGS CONTINUE ACROSS THE AREA. CONDTIONS WILL
SLOWLY IMPROVE FROM NORTHWEST TO SOUTHEAST TO VFR THROUGH THE
AFTERNOON INTO THE EARLY EVENING. GUSTY NORTHWEST WINDS WILL
SUBSIDE LATE TODAY INTO THIS EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...KS
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
853 AM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 847 AM CDT THU MAY 7 2015
SHOWER ACTIVITY CONTINUES TO SLOWLY ERODE ON THE WEST
SIDE...THOUGH THIS IS OCCURRING A BIT SLOWER THAN PREVIOUS
FORECAST. THEREFORE...HAVE INCREASED POPS A BIT THROUGH MID DAY.
COLD FRONT HAS PUSHED THROUGH CENTRAL NORTH DAKOTA...AND IS SLOWLY
EXITING THE EASTERN JAMES RIVER VALLEY. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE OBSERVATIONS PORTRAYING GUSTY NORTHWEST WINDS BETWEEN 25
AND 40 MPH BEHIND THE COLD FRONT. SURFACE COLD FRONT NOW MOVING
INTO JAMESTOWN AND SOUTH INTO OAKES.HAVE INCREASED WINDS CLOSER
TO THE 06Z MAV GUIDANCE THROUGH THE AFTERNOON. NEAR WIND ADVISORY
CRITERIA IN SOME SPOTS CURRENTLY...BUT WILL HOLD OFF AS UPSTREAM
WINDS IN SOUTHERN SASKATCHEWAN ARE MORE IN THE 20 TO 30 MPH RANGE.
LATEST RADAR AND WATER VAPOR IMAGERY DEPICT THE MID/UPPER LEVEL
LOW NOW CIRCULATING OVER THE SOUTHERN JAMES RIVER VALLEY. RADAR
RETURNS SLOWLY WEAKENING WEST OF BISMARCK AND THE CURRENT GRIDDED
FORECAST HAS THE POPS DIMINISHING FROM WEST TO EAST...WHICH IS ON
TRACK. BISMARCK ASOS TOTAL PRECIPITATION LAST 24HOURS HAS BEEN
0.72 INCHES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE LOW PRESSURE WAS CENTERED OVER THE EASTERN DAKOTAS AS OF 10Z
THURSDAY MORNING...WITH THE SURFACE FRONT JUST EAST OF KJMS. TIGHT
PRESSURE GRADIENT BEHIND THE LOW WILL PROVIDE SUSTAINED NORTHWEST
WINDS UP TO 20 KNOTS AND GUSTS TO 30 KNOTS THROUGH THE MORNING AND
AFTERNOON. SHOWERS WERE DISSIPATING ACROSS CENTRAL NORTH
DAKOTA...HOWEVER SHOWERS WILL BE POSSIBLE AT KBIS...KJMS...AND KMOT
THROUGH THE MORNING. CEILINGS WILL BE IN THE IFR TO MVFR CATEGORY
FOR MOST OF CENTRAL AND WESTERN NORTH DAKOTA THIS MORNING WITH
CEILINGS RISING FROM WEST TO EAST IN THE AFTERNOON AND NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJS
SHORT TERM...MM
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
601 AM CDT THU MAY 7 2015
.UPDATE...
ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE OBSERVATIONS PORTRAYING GUSTY NORTHWEST WINDS BETWEEN 25
AND 40 MPH BEHIND THE COLD FRONT. SURFACE COLD FRONT NOW MOVING
INTO JAMESTOWN AND SOUTH INTO OAKES.HAVE INCREASED WINDS CLOSER
TO THE 06Z MAV GUIDANCE THROUGH THE AFTERNOON. NEAR WIND ADVISORY
CRITERIA IN SOME SPOTS CURRENTLY...BUT WILL HOLD OFF AS UPSTREAM
WINDS IN SOUTHERN SASKATCHEWAN ARE MORE IN THE 20 TO 30 MPH RANGE.
LATEST RADAR AND WATER VAPOR IMAGERY DEPICT THE MID/UPPER LEVEL
LOW NOW CIRCULATING OVER THE SOUTHERN JAMES RIVER VALLEY. RADAR
RETURNS SLOWLY WEAKENING WEST OF BISMARCK AND THE CURRENT GRIDDED
FORECAST HAS THE POPS DIMINISHING FROM WEST TO EAST...WHICH IS ON
TRACK. BISMARCK ASOS TOTAL PRECIPITATION LAST 24HOURS HAS BEEN
0.72 INCHES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 533 AM CDT THU MAY 7 2015
SURFACE LOW PRESSURE WAS CENTERED OVER THE EASTERN DAKOTAS AS OF 10Z
THURSDAY MORNING...WITH THE SURFACE FRONT JUST EAST OF KJMS. TIGHT
PRESSURE GRADIENT BEHIND THE LOW WILL PROVIDE SUSTAINED NORTHWEST
WINDS UP TO 20 KNOTS AND GUSTS TO 30 KNOTS THROUGH THE MORNING AND
AFTERNOON. SHOWERS WERE DISSIPATING ACROSS CENTRAL NORTH
DAKOTA...HOWEVER SHOWERS WILL BE POSSIBLE AT KBIS...KJMS...AND KMOT
THROUGH THE MORNING. CEILINGS WILL BE IN THE IFR TO MVFR CATEGORY
FOR MOST OF CENTRAL AND WESTERN NORTH DAKOTA THIS MORNING WITH
CEILINGS RISING FROM WEST TO EAST IN THE AFTERNOON AND NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...MM
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
317 AM CDT THU MAY 7 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
FOCUS IN THE SHORT TERM WILL BE ON EXITING SHOWERS AND THE
POTENTIAL FOR FROST THURSDAY NIGHT.
THE LATEST 00 UTC SOLUTIONS OF THE ECMWF AND GFS ARE IN GOOD
AGREEMENT ON PROGRESSING THE UPPER LEVEL SHORTWAVE AND UPPER LEVEL
LOW NORTHEAST OUT OF NORTH DAKOTA SHORTLY AFTER 18 UTC THURSDAY.
BEHIND THE UPPER LEVEL LOW THE LATEST 05 UTC RUN OF THE HRRR SHOWS
SHOWERS ACROSS CENTRAL NORTH DAKOTA BECOMING SCATTERED BY 16 UTC.
FOR THIS REASON HAVE HASTENED THE EXIT OF PRECIPITATION ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. ALSO WITH OBSERVATIONS SHOWING
NOTHING IN THE WAY OF THUNDERSTORMS IN THE VICINITY OF NORTH
DAKOTA HAVE WENT AHEAD AND REMOVED ALL CHANCES FOR THUNDERSTORMS
THROUGH TODAY.
LOOKING AT THE FROST POTENTIAL FOR THURSDAY NIGHT THE BEST CHANCES
FOR FROST WILL BE WEST AND NORTH CENTRAL. MOS GUIDANCE FROM THE
GFS IS SHOWING THE LOWER 30S ACROSS THE NORTHWEST WHILE THE NAM
GUIDANCE IS SUGGESTING THE UPPER 20S. MODEL BLENDS ALSO HAVE SOME
LOW CLOUDS BUILDING BACK INTO WESTERN AND CENTRAL NORTH DAKOTA
WITH SOME MID LEVEL CLOUDS ALREADY IN PLACE. FOR NOW HAVE OPTED TO
GO WITH A MODEL BLEND FOR LOWS THURSDAY NIGHT WHICH SUGGEST A
POTENTIAL FOR FROST DEVELOPMENT ACROSS THE WEST AND PORTIONS OF
NORTH CENTRAL NORTH DAKOTA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM CDT THU MAY 7 2015
PATTERN CONTINUES TO EXHIBIT COOLER THAN NORMAL TEMPERATURES THROUGH
TUESDAY AS A POCKET OF COLDER AIR/850 TEMPERATURES HOVER BETWEEN 0C
AND -2C ACROSS WESTERN AND CENTRAL NORTH DAKOTA. A COUPLE OF
HIGHLIGHTS TO NOTE...LOWS IN THE 30S WILL LIKELY LEAD TO FROST
AND/OR FREEZE HEADLINES DURING THE LATE NIGHT/EARLY MORNING HOURS
THROUGH TUESDAY MORNING. THE SECOND HIGHLIGHT IS IN REGARDS TO
PRECIPITATION. THE MAIN THREAT STILL LOOKS TO OCCUR OVER SOUTHERN
AND EASTERN NORTH DAKOTA OVER THE WEEKEND INTO EARLY NEXT WEEK...AND
WITH THE COLDER AIR ALOFT AND COOLING AT NIGHT...EXPECT SOME SNOW
SHOWERS AT TIMES.
FRIDAY THROUGH THROUGH MONDAY NIGHT...ON FRIDAY A SURFACE HIGH WILL
SHIFT FROM SOUTH CENTRAL SASKATCHEWAN INTO MANITOBA WITH A
DRY/NORTHEAST FLOW ACROSS WESTERN AND CENTRAL NORTH DAKOTA. HIGHS
WILL BE IN THE 50S. BY FRIDAY NIGHT ATTENTION TURNS TOWARD THE NEXT
CLOSED UPPER LOW OVER THE FOUR CORNERS/SOUTHWEST CONUS AS IT BEGINS
TO EJECT EAST TO NORTHEAST INTO THE CENTRAL HIGH PLAINS SUNDAY INTO
MONDAY. SOME PHASING OCCURS BETWEEN THE NORTHERN/SOUTHERN STREAM
TROUGHS DURING THIS TIME. THE HIGHEST POPS REMAIN FOCUSED ACROSS
SOUTHERN NORTH DAKOTA SATURDAY/SATURDAY NIGHT...THEN PIVOTING INTO
SOUTH CENTRAL AND THE JAMES RIVER VALLEY SUNDAY THROUGH MONDAY. AS
MENTIONED ABOVE EXPECT SOME CHANCES FOR SNOW MIXING IN WITH THE RAIN
AT NIGHT/EARLY MORNING WITH LITTLE OR NO ACCUMULATIONS.
MONDAY NIGHT THROUGH WEDNESDAY...DRY WEATHER SLATED FOR MONDAY NIGHT
INTO WEDNESDAY. THE SUPERBLEND BEGINS TO SHOW A GRADUAL WARMING TREND
INTO THE LOWER 60S WEDNESDAY...AS 850MB TEMPERATURES WARM TO BETWEEN
+3C AND +5C. HOWEVER BOTH THE GFS AND ECMWF KEEP A CYCLONIC FLOW/SOME
TROUGHING OVER NORTH DAKOTA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 317 AM CDT THU MAY 7 2015
LIGHT TO MODERATE SHOWERS WERE IMPACTING MOST ALL OF WESTERN AND
CENTRAL NORTH DAKOTA. THE FRONTAL BOUNDARY AS OF 06 UTC WAS JUST
EAST OF KBIS AND KMOT AND PROGRESSING SLOWLY EAST. THROUGH THE
MORNING HOURS IFR AND MVFR CONDITIONS WILL IMPACT ALL OF CENTRAL
AND WESTERN NORTH DAKOTA TERMINALS WITH IMPROVING CONDITIONS FROM
WEST TO EAST THROUGH THURSDAY AFTERNOON AND NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MM
LONG TERM...KS
AVIATION...MM
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
812 PM CDT FRI MAY 8 2015
.UPDATE...
ADJUSTED RAIN CHANCES TONIGHT...MAINLY TO LOWER THEM IN WESTERN
OKLAHOMA. TWEAKED OVERNIGHT DOWNWARDS A BIT.
&&
.DISCUSSION...
LINE OF STRONG TO SEVERE STORMS CONTINUES NEAR I-35 SOUTH OF
OKLAHOMA CITY AND WILL PUSH EAST OVER THE NEXT FEW HOURS.
VERY HEAVY RAINFALL OF 1 TO 3 INCHES AND FLASH FLOODING REMAIN
THE BIGGEST CONCERNS AT THE MOMENT WITH SOME REPORTS OF DAMAGING
WINDS AND SEVERE HAIL. A FEW TORNADOES REMAIN POSSIBLE.
THINK THE SEVERE WEATHER THREAT HAS ENDED TONIGHT WEST OF A
PONCA CITY TO OKLAHOMA CITY TO WICHITA FALLS LINE. DECREASED RAIN
CHANCES TONIGHT IN THESE LOCATIONS.
LATEST HRRR RUNS HINT THAT THERE MAY BE ISOLATED STORM DEVELOPMENT
AFTER 4 AM TONIGHT...PARTICULARLY IN WESTERN NORTH TEXAS AND FAR
WESTERN OKLAHOMA. IF THESE STORMS FORM...THERE WOULD BE A LOW
CHANCE OF THESE STORMS OF BEING SEVERE WITH LARGE HAIL. CONFIDENCE
OF THESE STORMS FORMING REMAINS LOW. KEPT LOW RAIN CHANCES TO
ACCOUNT FOR THIS POSSIBILITY.
SOME FOG MAY FORM LATE TONIGHT PARTICULARLY OVER WESTERN
OKLAHOMA. DID NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 646 PM CDT FRI MAY 8 2015/
DISCUSSION...
SEVERE STORMS AND FLASH FLOODING WILL CONTINUE THIS EVENING.
LATEST RADARS INDICATED NUMEROUS STORMS FROM SEYMOUR AND WICHITA
FALLS TEXAS TO OKLAHOMA CITY TO PONCA CITY. STORMS WILL CONTINUE
TO PUSH SOUTHEAST THIS EVENING AND SEEM TO BECOME MORE LINEAR IN
NATURE AS THEY AFFECT LOCATIONS SOUTHEAST OF I-44.
THE MAIN SEVERE HAZARDS REMAIN DAMAGING WINDS AND VERY LARGE HAIL
WITH A FEW TORNADOES. THE TORNADO POTENTIAL MAY INCREASE OVER THE
NEXT FEW HOURS AS LOW LEVEL SHEAR INCREASES ACROSS SOUTHERN
OKLAHOMA...ESPECIALLY IF STORMS REMAIN DISCRETE. WILL CLOSELY
MONITOR.
FLASH FLOODING MAY BE THE BIGGER CONCERN THIS TONIGHT WITH
RAINFALL RATES OF 1 TO 3 INCHES PER HOUR WITH THE STRONGEST
STORMS.
STRONG WAKE LOW WINDS SEEM TO BE DEVELOPING ACROSS SOUTHWESTERN
OKLAHOMA AND WESTERN NORTH TEXAS ON THE BACK EDGE OF STORMS. SOME
GUSTS OVER 50 MPH MAY OCCUR.
STORMS WILL PUSH INTO EASTERN OKLAHOMA BY MIDNIGHT...SLOWLY ENDING
THE SEVERE POTENTIAL TONIGHT. IT SEEMS UNLIKELY THAT ADDITIONAL
SEVERE STORMS WILL FORM BETWEEN MIDNIGHT AND 6 AM TONIGHT.
AVIATION DISCUSSION FOR THE 00Z TAFS IS BELOW.
MBS
AVIATION...
LOW CONFIDENCE CONTINUES WITH THE TAFS.
ONGOING TSRA WILL BE EAST OF ALL TAF SITES BY 03Z. BRIEF VARIABLE
GUSTY WINDS AND IFR OR LOWER CONDITIONS ARE POSSIBLE WITH TSRA.
STRONG EAST TO NORTHEAST WINDS WITH GUSTS OVER 30 KT COULD OCCUR
FOR A 1 TO 2 HOUR PERIOD AS STORMS END THROUGH 05Z.
WIDESPREAD MVFR/IFR CONDITIONS WILL LIKELY FORM 06-18Z. 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 AFTER 03Z.
KEPT VCTS MENTION AT MANY SITES...MAINLY 12-18Z. BRIEF VARIABLE
GUSTY WINDS AND MVFR OR LOWER CONDITIONS ARE POSSIBLE. STORM
COVERAGE AND LOCATIONS REMAIN VERY UNCERTAIN.
MBS
PREV DISCUSSION... /ISSUED 336 PM CDT FRI MAY 8 2015/
DISCUSSION...
THE STORM COMPLEX THAT DEVELOPED THIS AFTERNOON OVER WEST TEXAS
WILL PROGRESS SLOWLY EAST LATE THIS AFTERNOON AND EARLY EVENING.
A SURFACE BOUNDARY EXTENDING ROUGHLY ALONG I-40 SHOULD AT LEAST
SLIGHTLY REDUCE THE SEVERE WEATHER POTENTIAL TO THE NORTH.
LATER TONIGHT...THINGS BECOME MUCH LESS CLEAR. WIDESPREAD ELEVATED
CONVECTION SEEMS LIKELY AS THE LARGE STORM SYSTEM TO OUR WEST
CONTINUES TO PLOD EAST. THIS MAY CAUSE ADVERSE EFFECTS ON THE
FORECAST FOR TOMORROW. IN FACT...MODEL GUIDANCE IS ALL OVER THE
PLACE WITH PRECIPITATION FOR TONIGHT THROUGH TOMORROW NIGHT.
GUIDANCE FINALLY BECOMES COHERENT AGAIN ON SUNDAY...AS THE MAIN
UPPER WAVE DEPARTS...AND A COLD FRONT IS DRIVEN SOUTHEAST INTO
OKLAHOMA.
THE NATURE OF THE FORECAST STORM MOVEMENT AND MOISTURE QUANTITY
WILL BE QUITE FAVORABLE FOR VERY HEAVY RAINFALL OVER MOST OF OUR
FORECAST AREA. A FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY
EVENING. SOUTHEAST OKLAHOMA LOOKS LIKE IT WILL BEAR THE MAIN BRUNT
OF HEAVY RAIN...MAINLY LATE IN THE PERIOD...AND THE WATCH MAY NEED
TO BE EXTENDED FOR THAT AREA IN LATER FORECASTS...DEPENDING ON
EXACTLY WHEN THE RAIN FINALLY EXITS OUR FORECAST AREA.
MONDAY LOOKS LIKE A MILD AND DRY DAY...BEFORE RAIN CHANCES RETURN
ON TUESDAY. MODELS AGREE ON A MOIST FLOW NEAR THE SURFACE...WITH
SOUTHWEST FLOW PREVAILING ALOFT. ASSUMING THIS HAPPENS...THERE
WILL BE RELATIVELY HIGH CHANCES FOR RAIN FROM TUESDAY THROUGH AT
LEAST THE FOLLOWING WEEKEND. SINCE THE MAIN TARGET OF THE RAIN
NEXT WEEK WILL PROBABLY BE THE EASTERN HALF OF OKLAHOMA...FLOODING
MAY BECOME A MAJOR CONCERN AGAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 77 63 75 / 100 70 50 50
HOBART OK 60 78 57 78 / 20 70 30 20
WICHITA FALLS TX 63 80 63 78 / 20 70 60 60
GAGE OK 59 78 51 74 / 20 70 20 10
PONCA CITY OK 64 77 63 76 / 100 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.
&&
$$
17/17
AREA FORECAST DISCUSSION
NWS TULSA OK
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 67 79 68 78 / 80 80 70 80
FSM 69 81 66 79 / 70 80 60 80
MLC 68 78 69 76 / 80 80 70 80
BVO 65 78 65 78 / 80 80 70 60
FYV 67 77 64 74 / 70 80 60 80
BYV 66 81 65 76 / 70 70 60 80
MKO 68 78 66 76 / 80 80 70 80
MIO 65 80 66 77 / 70 80 70 80
F10 67 77 67 76 / 80 80 70 80
HHW 70 80 68 78 / 70 80 60 80
&&
.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...30
LONG TERM....30
AVIATION...21
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1042 AM EDT THU MAY 7 2015
.DISCUSSION...
LITTLE CHANGE IN THE WEATHER PATTERN OVER THE PAST 24 HOURS SHOULD
RESULT IN TODAY BEING VERY SIMILAR TO YESTERDAY. 12Z RAOBS AROUND
THE REGION SHOW 850 MB TEMPS BEING A DEGREE OR SO ABOVE
YESTERDAY...SO HIGHS TEMPS TODAY SHOULD BE IN THE MID 80S IN THE
VALLEY...WITH A FEW SPOTS TOUCHING THE UPPER 80S. THIS WILL
NECESSITATE A SLIGHT UPWARD ADJUSTMENT IN FORECAST TEMPS. SCATTERED
AFTERNOON SHOWERS ARE EXPECTED IN THE HIGHER TERRAIN AND SW
VA...WITH MOVEMENT TOWARD THE W-SW THAT MAY BRING A FEW OF THEM
INTO THE VALELY BEFORE DISSIPATING. THE HRRR HAD A GOOD HANDLE ON
THIS YESTERDAY...AND WILL BE FOLLOWED AGAIN TODAY. SOME EXPANSION
OF SLIGHT CHANCE POPS WILL BE MADE INTO THE VALLEY WITH THE UPDATE.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1244 PM CDT THU MAY 7 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE LOW
TO MID LEVEL CLOUDS ACROSS MOST OF THE CWA EARLY THIS AFTERNOON.
CEILINGS WERE NEAR 1200FT AT KT65 AND KHRL TO NEAR 2200FT AT KBKS.
VISIBILITIES WERE NEAR 4SM WITH MIST AT KPIL TO NEAR 6SM WITH HAZE
AT KMFE. EXPECT MVFR CONDITIONS TO PREVAIL THE REST OF THE
AFTERNOON INTO THE EVENING BEFORE IFR CONDITIONS DEVELOP TONIGHT
AS ABUNDANT LOW TO MID LEVEL MOISTURE UNDER THE INVERSION AT 850MB
CONTINUES TO PROVIDE LOW CEILINGS THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 535 AM CDT THU MAY 7 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...LOW MVFR CIGS ARE OCCURRING ACROSS ALL OF DEEP SOUTH
TEXAS. MUCH LIKE THE PAST SEVERAL DAYS...LOW MVFR WILL SLOWLY
RISE THROUGH THE MORNING HOURS THAT BECOMING LOW VFR THIS
AFTERNOON. SFC FEATURES HAVE NOT CHANGED MUCH WHICH WILL LEAD TO
ANOTHER BREEZY DAYS WITH GUSTS TO 25 KNOTS POSSIBLE THIS
AFTERNOON. WINDS WILL DECREASE AFTER SUNSET WITH CIGS LOWERING TO
MVFR THIS EVENING THEN PERHAPS IFR OVERNIGHT.
PREV DISCUSSION... /ISSUED 328 AM CDT THU MAY 7 2015/
SHORT TERM /NOW THROUGH FRIDAY/...H5 TROF WILL SLIDE SOUTHWARD
ACROSS CALIFORNIA AND INTO THE DESERT SOUTHWEST. MID LEVEL RIDGE
WILL BE DRAPED ACROSS THE WESTERN GULF OF MEXICO AND A S/W TROUGH
OFF THE FLORIDA COAST. PERSISTENT SOUTHEASTERLY FLOW WILL CONTINUE
WITH SFC HIGH PRESSURE ACROSS THE NORTHEASTERN GULF OF MEXICO AND
LOW PRESSURE ACROSS THE HIGH PLAINS. BREEZY CONDITIONS WILL
CONTINUE THROUGH THE SHORT TERM PERIOD WITH GUSTS TO 25-30 MPH
POSSIBLE IN THE AFTERNOON HOURS. 850-700MB TEMPERATURES WARM
THROUGH THE PERIOD SO AN INCREASE AN AFTERNOON HIGHS UP INTO THE
LOWER 90S MIDDLE/UPPER VALLEY WITH UPPER 80S IN THE LOWER VALLEY
EACH DAY.
FOR PRECIPITATION CHANCES...HAVE SLIGHT CHANCE POPS THIS MORNING FOR
ANY ISOLATED SHOWER THAT HAPPENS TO DEVELOP UNDERNEATH THE STRONG
INVERSION /MUCH LIKE THE PAST SEVERAL DAYS/. MODELS ONCE AGAIN
PROG A WEAK DISTURBANCE MOVING ACROSS THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. HRRR AND GFS DEVELOP THUNDERSTORMS OVER THE
SIERRA MADRES THIS AFTERNOON AND MOVE EAST TOWARDS THE UPPER
VALLEY. WILL MAINTAIN SLIGHT CHANCE POPS OUT WEST THIS EVENING
THEN DECREASE OVERNIGHT AS CIN INCREASES RAPIDLY.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE APPROACH AND
PASSAGE OF A 500 MB TROUGH THROUGH THE TEXAS BIG BEND WILL ONCE
AGAIN INITIATE THUNDERSTORMS OVER THE NEIGHBORING HIGH TERRAIN OF
MEXICO...AND SOME OF THIS ACTIVITY MAY AFFECT THE BRO CWFA...
ESPECIALLY THE WESTERN THIRD AND NORTHERN HALF OF THE REGION.
STORM PREDICTION CENTER HAS A MARGINAL TO ENHANCED RISK OF SEVERE
WEATHER FOR MUCH OF TEXAS NORTH OF THE RIO GRANDE VALLEY AND DEEP
SOUTH TEXAS...SO SUCCESSIVE SHIFTS WILL HAVE TO MONITOR FOR THE
POSSIBILITY THAT SOME OF THIS STRONG TO SEVERE THUNDERSTORM
ACTIVITY MAY SNEAK INTO THE BRO CWFA FRIDAY NIGHT. AFTERWARDS...DRY
WEATHER WILL PREVAIL UNTIL ANOTHER POSSIBLE ROUND OF THUNDERSTORMS
OUT WEST SUNDAY NIGHT. A GREATLY ENHANCED OPPORTUNITY FOR RAINFALL
IS ANTICIPATED MONDAY THROUGH WEDNESDAY DUE TO THE INTRUSION AND
STALLING OF A WEAK COLD FRONT...A SOUTHWEST-TO-NORTHEAST 500 MB
FLOW OVERHEAD...AND THE FORMATION AND PERSISTENCE OF A SURFACE
TROUGH OF LOW PRESSURE WITHIN THE BRO CWFA. WITH DEEP TROPICAL
MOISTURE EXPECTED TO ALSO BE IN PLACE...WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES...THE POTENTIAL FOR LOCALLY HEAVY AND
FLOODING RAINFALL MAY EXIST MONDAY THROUGH WEDNESDAY. HOWEVER
.HAVE NOT INCLUDED THIS IN THE UPCOMING FORECAST AND WILL KEEP
AN EYE ON THE POTENTIAL FOR THIS HEAVY/FLOODING RAINFALL THROUGH
THE NEXT SEVERAL DAYS. NO MAJOR SURPRISES FOR THE TEMPERATURES...
NEAR TO SLIGHTLY ABOVE NORMAL THROUGHOUT THE ENTIRE LONG TERM
FORECAST PERIOD.
MARINE...NOW THROUGH FRIDAY...SEAS WERE NEAR 5 FEET WITH SOUTHEAST
WINDS NEAR 16 KNOTS AT BUOY020 THIS MORNING. MODERATE TO STRONG
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY AS
THE PRESSURE GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF
MEXICO. WILL HAVE SCEC ACROSS ALL LOWER TEXAS COASTAL WATERS TODAY
AND GULF WATERS TONIGHT. FOR FRIDAY SCEC WILL BE NEEDED ACROSS ALL
LOWER TEXAS COASTAL WATERS ONCE AGAIN.
FRIDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE CENTERED
JUST SOUTH OF THE FLORIDA PENINSULA WILL INTERACT WITH PERSISTENT
LOW PRESSURE OVER THE CENTRAL PLAINS FROM FRIDAY NIGHT THROUGH
THE WEEKEND...PRODUCING SMALL CRAFT ADVISORY WINDS/SEAS ALONG THE
LOWER TEXAS COAST THROUGH THIS PERIOD. ALTHOUGH HIGH PRESSURE WILL
BECOME MORE IN CONTROL OVER THE WESTERN GULF OF MEXICO AFTERWARDS
.ROUGH SWELLS FROM THE EAST-SOUTHEAST TO SOUTHEAST WILL CONTINUE
THE CHANCE FOR SMALL CRAFT ADVISORY MONDAY THROUGH WEDNESDAY...
ESPECIALLY FOR THE FAR OFFSHORE GULF OF MEXICO WATERS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
61/67/BIRCHFIELD
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1231 PM CDT THU MAY 7 2015
.UPDATE...
WILL UPDATE TO INCREASE AFTN POPS NERN ZONES WHERE A CONVECTIVE
COMPLEX WILL CONTINUE TO MOVE SLOWLY ACROSS. APPEARS COMPLEX
ITSELF MAY TAKE MORE OF AN EWD TURN FEEDING INTO INCREASINGLY
MOIST AND UNSTABLE AIR ADVECTING INTO THAT AREA FROM THE SOUTH.
UNCERTAINTY REIGNS FURTHER TO WEST WITH POTENTIAL FOR
REDEVELOPMENT OF STORMS LOOKING MORE UNLIKELY WITH SUBSIDENCE ON
IN THE WAKE OF THE THUNDER COMPLEX AND ASSOCIATED SHORT WAVE
TROUGH. HEAVY RAIN TO REMAIN A THREAT THROUGH THE AFTN...BUT
SEVERE REMAINS A POSSIBILITY AS STORMS BUILD EWD ACROSS THE
ROLLING PLAINS.
&&
.AVIATION...
UPPER TROUGH TO CONTINUE TO MOVE SLOWLY TO THE ENE ACROSS THE AREA
WITH TS COMPLEX GRADUALLY SHIFTING THAT DIRECTION AS WELL. THIS
WILL TAKE TS AWAY FROM KLBB AND KPVW WITHIN THE FIRST HOUR OR TWO
OF THE TAF VALID TIME. COMPLEX LIKELY TO AFFECT KCDS THRU MIDDLE
AFTN. REDEVELOPMENT OF TS FURTHER WEST THIS AFTN POSSIBLE BUT NOT
LOOKING AS LIKELY WITH CLOSE PROXIMITY TO DOWNWARD MOTION AROUND
EDGE OF THE CONVECTIVE COMPLEX. FINALLY...IFR CIGS LIKELY TO
RETURN TO ALL TERMINALS OVERNIGHT TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 1017 AM CDT THU MAY 7 2015/
UPDATE...
QUICK UPDATE TO INCREASE POPS FOR THE REMAINDER OF THE MORNING. AN
UPPER LEVEL SHORT WAVE TROUGH LIFTING NEWD ACROSS SERN NM ACTING
ON ELEVATED INSTABILITY HELPING KICK OFF SCATTERED TO NUMEROUS
THUNDERSTORMS. THIS TROUGH IS EXPECTED TO EXIT THE REGION BY MID
AFTERNOON AND ITS EGRESS COULD HAVE A NEGATIVE EFFECT ON
CONVECTIVE INITIATION LATER THIS AFTERNOON GIVEN EXPECTATION OF
SOME DOWNWARD MOTION IN ITS WAKE AND THE RELEASE OF POTENTIAL
ENERGY THIS MORNING WITH THIS ROUND OF STORMS. WILL KEEP POST-18Z
POPS ALONE ATTM WITH THE WEST TO EAST GRADIENT LOOKING FINE AS
SOME SHOWERS AND STORMS LIKELY TO LINGER PAST 18Z. NO OTHER
CHANGES MADE ATTM.
PREV DISCUSSION... /ISSUED 351 AM CDT THU MAY 7 2015/
SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 40 20 10 20
TULIA 79 54 81 54 / 70 20 30 40
PLAINVIEW 79 55 81 54 / 70 30 30 40
LEVELLAND 82 56 83 56 / 50 30 20 50
LUBBOCK 80 58 84 58 / 50 30 30 40
DENVER CITY 82 54 83 53 / 40 20 20 50
BROWNFIELD 83 56 85 57 / 50 30 30 50
CHILDRESS 82 61 84 64 / 70 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1017 AM CDT THU MAY 7 2015
.UPDATE...
QUICK UPDATE TO INCREASE POPS FOR THE REMAINDER OF THE MORNING. AN
UPPER LEVEL SHORT WAVE TROUGH LIFTING NEWD ACROSS SERN NM ACTING
ON ELEVATED INSTABILITY HELPING KICK OFF SCATTERED TO NUMEROUS
THUNDERSTORMS. THIS TROUGH IS EXPECTED TO EXIT THE REGION BY MID
AFTERNOON AND ITS EGRESS COULD HAVE A NEGATIVE EFFECT ON
CONVECTIVE INITIATION LATER THIS AFTERNOON GIVEN EXPECTATION OF
SOME DOWNWARD MOTION IN ITS WAKE AND THE RELEASE OF POTENTIAL
ENERGY THIS MORNING WITH THIS ROUND OF STORMS. WILL KEEP POST-18Z
POPS ALONE ATTM WITH THE WEST TO EAST GRADIENT LOOKING FINE AS
SOME SHOWERS AND STORMS LIKELY TO LINGER PAST 18Z. NO OTHER
CHANGES MADE ATTM.
&&
.PREV DISCUSSION... /ISSUED 647 AM CDT THU MAY 7 2015/
AVIATION...
MVFR TO IFR CONDITIONS IN PLACE AT ALL THREE TAF SITES ONCE AGAIN
THIS MORNING. EXPECT TO SEE A GRADUAL TRANSITION TO VFR BY LATE
THIS MORNING AS CEILINGS START TO LIFT. THERE COULD BE SHOWERS AND
THUNDERSTORMS LATE THIS MORNING THROUGH THIS EVENING WITH THE
GREATEST CHANCES AT KCDS. STORMS COULD DEVELOP AS FAR WEST AS KLBB
AND KPVW BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS
AT THIS TIME. WILL HAVE TO EVALUATE THROUGH THE DAY FOR POSSIBLE
INCLUSION IN LATER TAF ISSUANCES. ANY STORMS THAT DEVELOP WILL
MOVE AWAY FROM THE TAF SITES AFTER 06Z TOMORROW BUT WE COULD SEE
ANOTHER ROUND OF MVFR TO IFR CONDITIONS TOMORROW MORNING.
JORDAN
PREV DISCUSSION... /ISSUED 351 AM CDT THU MAY 7 2015/
SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 40 20 10 20
TULIA 79 54 81 54 / 70 20 30 40
PLAINVIEW 79 55 81 54 / 70 30 30 40
LEVELLAND 82 56 83 56 / 50 30 20 50
LUBBOCK 80 58 84 58 / 50 30 30 40
DENVER CITY 82 54 83 53 / 40 20 20 50
BROWNFIELD 83 56 85 57 / 50 30 30 50
CHILDRESS 82 61 84 64 / 70 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/99
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
647 AM CDT THU MAY 7 2015
.AVIATION...
MVFR TO IFR CONDITIONS IN PLACE AT ALL THREE TAF SITES ONCE AGAIN
THIS MORNING. EXPECT TO SEE A GRADUAL TRANSITION TO VFR BY LATE
THIS MORNING AS CEILINGS START TO LIFT. THERE COULD BE SHOWERS AND
THUNDERSTORMS LATE THIS MORNING THROUGH THIS EVENING WITH THE
GREATEST CHANCES AT KCDS. STORMS COULD DEVELOP AS FAR WEST AS KLBB
AND KPVW BUT CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS
AT THIS TIME. WILL HAVE TO EVALUATE THROUGH THE DAY FOR POSSIBLE
INCLUSION IN LATER TAF ISSUANCES. ANY STORMS THAT DEVELOP WILL
MOVE AWAY FROM THE TAF SITES AFTER 06Z TOMORROW BUT WE COULD SEE
ANOTHER ROUND OF MVFR TO IFR CONDITIONS TOMORROW MORNING.
JORDAN
&&
.PREV DISCUSSION... /ISSUED 351 AM CDT THU MAY 7 2015/
SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 20 20 10 20
TULIA 79 54 81 54 / 30 20 30 40
PLAINVIEW 79 55 81 54 / 30 30 30 40
LEVELLAND 82 56 83 56 / 20 30 20 50
LUBBOCK 80 58 84 58 / 30 30 30 40
DENVER CITY 82 54 83 53 / 20 20 20 50
BROWNFIELD 83 56 85 57 / 30 30 30 50
CHILDRESS 82 61 84 64 / 50 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
535 AM CDT THU MAY 7 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...LOW MVFR CIGS ARE OCCURRING ACROSS ALL OF DEEP SOUTH
TEXAS. MUCH LIKE THE PAST SEVERAL DAYS...LOW MVFR WILL SLOWLY
RISE THROUGH THE MORNING HOURS THAT BECOMING LOW VFR THIS
AFTERNOON. SFC FEATURES HAVE NOT CHANGED MUCH WHICH WILL LEAD TO
ANOTHER BREEZY DAYS WITH GUSTS TO 25 KNOTS POSSIBLE THIS
AFTERNOON. WINDS WILL DECREASE AFTER SUNSET WITH CIGS LOWERING TO
MVFR THIS EVENING THEN PERHAPS IFR OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT THU MAY 7 2015/
SHORT TERM /NOW THROUGH FRIDAY/...H5 TROF WILL SLIDE SOUTHWARD
ACROSS CALIFORNIA AND INTO THE DESERT SOUTHWEST. MID LEVEL RIDGE
WILL BE DRAPED ACROSS THE WESTERN GULF OF MEXICO AND A S/W TROUGH
OFF THE FLORIDA COAST. PERSISTENT SOUTHEASTERLY FLOW WILL CONTINUE
WITH SFC HIGH PRESSURE ACROSS THE NORTHEASTERN GULF OF MEXICO AND
LOW PRESSURE ACROSS THE HIGH PLAINS. BREEZY CONDITIONS WILL
CONTINUE THROUGH THE SHORT TERM PERIOD WITH GUSTS TO 25-30 MPH
POSSIBLE IN THE AFTERNOON HOURS. 850-700MB TEMPERATURES WARM
THROUGH THE PERIOD SO AN INCREASE AN AFTERNOON HIGHS UP INTO THE
LOWER 90S MIDDLE/UPPER VALLEY WITH UPPER 80S IN THE LOWER VALLEY
EACH DAY.
FOR PRECIPITATION CHANCES...HAVE SLIGHT CHANCE POPS THIS MORNING FOR
ANY ISOLATED SHOWER THAT HAPPENS TO DEVELOP UNDERNEATH THE STRONG
INVERSION /MUCH LIKE THE PAST SEVERAL DAYS/. MODELS ONCE AGAIN
PROG A WEAK DISTURBANCE MOVING ACROSS THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. HRRR AND GFS DEVELOP THUNDERSTORMS OVER THE
SIERRA MADRES THIS AFTERNOON AND MOVE EAST TOWARDS THE UPPER
VALLEY. WILL MAINTAIN SLIGHT CHANCE POPS OUT WEST THIS EVENING
THEN DECREASE OVERNIGHT AS CIN INCREASES RAPIDLY.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE APPROACH AND
PASSAGE OF A 500 MB TROUGH THROUGH THE TEXAS BIG BEND WILL ONCE
AGAIN INITIATE THUNDERSTORMS OVER THE NEIGHBORING HIGH TERRAIN OF
MEXICO...AND SOME OF THIS ACTIVITY MAY AFFECT THE BRO CWFA...
ESPECIALLY THE WESTERN THIRD AND NORTHERN HALF OF THE REGION.
STORM PREDICTION CENTER HAS A MARGINAL TO ENHANCED RISK OF SEVERE
WEATHER FOR MUCH OF TEXAS NORTH OF THE RIO GRANDE VALLEY AND DEEP
SOUTH TEXAS...SO SUCCESSIVE SHIFTS WILL HAVE TO MONITOR FOR THE
POSSIBILITY THAT SOME OF THIS STRONG TO SEVERE THUNDERSTORM
ACTIVITY MAY SNEAK INTO THE BRO CWFA FRIDAY NIGHT. AFTERWARDS...DRY
WEATHER WILL PREVAIL UNTIL ANOTHER POSSIBLE ROUND OF THUNDERSTORMS
OUT WEST SUNDAY NIGHT. A GREATLY ENHANCED OPPORTUNITY FOR RAINFALL
IS ANTICIPATED MONDAY THROUGH WEDNESDAY DUE TO THE INTRUSION AND
STALLING OF A WEAK COLD FRONT...A SOUTHWEST-TO-NORTHEAST 500 MB
FLOW OVERHEAD...AND THE FORMATION AND PERSISTENCE OF A SURFACE
TROUGH OF LOW PRESSURE WITHIN THE BRO CWFA. WITH DEEP TROPICAL
MOISTURE EXPECTED TO ALSO BE IN PLACE...WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES...THE POTENTIAL FOR LOCALLY HEAVY AND
FLOODING RAINFALL MAY EXIST MONDAY THROUGH WEDNESDAY. HOWEVER
..HAVE NOT INCLUDED THIS IN THE UPCOMING FORECAST AND WILL KEEP
AN EYE ON THE POTENTIAL FOR THIS HEAVY/FLOODING RAINFALL THROUGH
THE NEXT SEVERAL DAYS. NO MAJOR SURPRISES FOR THE TEMPERATURES...
NEAR TO SLIGHTLY ABOVE NORMAL THROUGHOUT THE ENTIRE LONG TERM
FORECAST PERIOD.
MARINE...NOW THROUGH FRIDAY...SEAS WERE NEAR 5 FEET WITH SOUTHEAST
WINDS NEAR 16 KNOTS AT BUOY020 THIS MORNING. MODERATE TO STRONG
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY AS
THE PRESSURE GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF
MEXICO. WILL HAVE SCEC ACROSS ALL LOWER TEXAS COASTAL WATERS TODAY
AND GULF WATERS TONIGHT. FOR FRIDAY SCEC WILL BE NEEDED ACROSS ALL
LOWER TEXAS COASTAL WATERS ONCE AGAIN.
FRIDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE CENTERED
JUST SOUTH OF THE FLORIDA PENINSULA WILL INTERACT WITH PERSISTENT
LOW PRESSURE OVER THE CENTRAL PLAINS FROM FRIDAY NIGHT THROUGH
THE WEEKEND...PRODUCING SMALL CRAFT ADVISORY WINDS/SEAS ALONG THE
LOWER TEXAS COAST THROUGH THIS PERIOD. ALTHOUGH HIGH PRESSURE WILL
BECOME MORE IN CONTROL OVER THE WESTERN GULF OF MEXICO AFTERWARDS
..ROUGH SWELLS FROM THE EAST-SOUTHEAST TO SOUTHEAST WILL CONTINUE
THE CHANCE FOR SMALL CRAFT ADVISORY MONDAY THROUGH WEDNESDAY...
ESPECIALLY FOR THE FAR OFFSHORE GULF OF MEXICO WATERS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
351 AM CDT THU MAY 7 2015
.SHORT TERM...
JUST AS WE SAW LAST NIGHT...STORMS MOVED OUT OF THE AREA OR WEAKENED
JUST AFTER MIDNIGHT LOCAL TIME AND THE DRYLINE CONTINUES TO SLOSH
BACK TO THE WEST. ONE DIFFERENCE IS THAT THERE IS A SUBTLE
SHORTWAVE OVER SOUTHEAST NEW MEXICO THAT IS TRYING TO GENERATE SOME
SHOWERS AS IT APPROACHES THE REGION. THIS SHORTWAVE MAY COMPLICATE
MATTERS FOR THIS AFTERNOON IF PRECIPITATION CAN DEVELOP AND BECOME
MORE EXPANSIVE ACROSS THE FORECAST AREA. THE RAP AND HRRR AND TO
SOME EXTENT THE NAM ARE TRYING TO DEVELOP AN AREA OF PRECIPITATION
ACROSS THE SOUTHWESTERN SOUTH PLAINS AND SOUTHEASTERN NEW MEXICO
THAT SPREADS NORTHEAST BEFORE SUNRISE. AMPLE LOW LEVEL MOISTURE
WILL BE IN PLACE TO THE EAST OF THE DRYLINE AS INDICATED BY LOW
CLOUDS AND PATCHY FOG ONCE AGAIN DEVELOPING ACROSS THE ROLLING
PLAINS AND STARTING TO SPREAD OVER THE CAPROCK. PULLED POPS BACK TO
THE WEST FOR THIS MORNING BUT KEPT THEM BARELY IN THE SLIGHT CHANCE
RANGE.
STORM CHANCES FOR THIS AFTERNOON WILL ONCE AGAIN DEPEND ON WHERE THE
DRYLINE MIXES TO AND IF ANY OTHER WEAK SHORTWAVES WILL MOVE ACROSS
THE AREA TO PROVIDE SOME WEAK LIFT TO INITIATE STORMS. FORECAST
SOUNDINGS STILL SHOW A BIT OF A WEAK CAP OVER THE AREA THIS MORNING
BUT THIS COULD EASILY BE OVERCOME BY DAYTIME HEATING. MLCAPE VALUES
WILL ONCE AGAIN CLIMB INTO THE 2000-3000 J/KG SO THERE WILL BE
PLENTY OF ENERGY FOR STORMS TO ACCESS. WIND PROFILES SHOW A BIT OF
A WEAKNESS BETWEEN 850 AND 700 HPA WHICH MAY IMPACT STORM MORPHOLOGY
BUT AMOUNT OF INSTABILITY AND DECENT VENTILATION ALOFT POINTS
TOWARDS THE POSSIBILITY OF SUPERCELLS WITH LARGE HAIL THE PREDOMINANT
THREAT. HOWEVER...RADAR LOOP SHOWS THAT THERE IS A POSSIBLE OUTFLOW
BOUNDARY FROM THE STORMS OVER OKLAHOMA/NORTH TEXAS THAT IS PUSHING
WEST. ADD IN BOUNDARIES LEFT OVER FROM ANY STORMS THAT MAY OR MAY
NOT DEVELOP THIS MORNING AND THERE COULD BE SOME LOCALIZED THREAT
FOR TORNADO DEVELOPMENT ALONG THESE BOUNDARIES. UNFORTUNATELY IT
IS TOO HARD TO TELL RIGHT NOW IF THERE WILL BE ANY ONE AREA OVER
ANOTHER THAT HAS A GREATER THREAT FOR TORNADOES.
TEMPERATURES WILL BE FAIRLY CLOSE TO WHAT WE SAW YESTERDAY FOR BOTH
MIN AND MAX TEMPS. AS MENTIONED EARLIER...DID INCREASE POPS THIS
MORNING AND ALSO INCREASED POPS ACROSS THE ROLLING PLAINS FOR THIS
AFTERNOON. PUT MENTION OF SEVERE IN FOR THE EASTERN TWO THIRDS OF
THE FORECAST AREA FOR THIS AFTERNOON AND EARLY EVENING BUT TAPERED
POPS OFF AFTER MIDNIGHT A BIT FOLLOWING THE DIURNAL CYCLE WE HAVE
SEEN THE LAST SEVERAL DAYS.
JORDAN
.LONG TERM...
LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE PRIMARY FOCUS ON THE
ACTIVE EARLY MAY WEATHER THAT WILL PERSIST IN THE REGION INTO
SATURDAY.
THE UPPER LOW CURRENTLY DIGGING SOUTHWARD ACROSS THE WESTERN STATES
WILL BE CENTERED OVER SOUTHERN CA/NV TO KICK OF THE EXTENDED FRIDAY.
THERE IS GOOD AGREEMENT THAT THE LOW WILL MOVE STEADILY EASTWARD TO
NEAR THE FOUR CORNERS AROUND MIDDAY SATURDAY BEFORE EMERGING OVER
THE CENTRAL HIGH PLAINS ON SUNDAY. THIS TRACK WILL KEEP WEST TEXAS
UNDER STRENGTHENING SOUTHWESTERLY FLOW ALOFT WHILE RICH MOISTURE
ALREADY ENCOMPASSING MUCH OF THE LONE STAR STATE DOES NOT GO
ANYWHERE. VERY STEEP MID-LEVEL LAPSES ATOP THE RICH AND MOIST
BOUNDARY LAYER EAST OF THE DRYLINE WILL RESULT IN STRONG INSTABILITY
EVERY DAY...THOUGH ANY EARLY DAY CONVECTION AND CLOUD COVER WILL
DICTATE WHERE THE MOST VOLATILE AIR WILL RESIDE ON ANY PARTICULAR
AFTERNOON/EVENING. THE ABOVE FACTORS WILL WILL SET THE STAGE FOR
ROBUST MOIST CONVECTION ALONG AND EAST OF THE DRYLINE THE NEXT FEW
DAYS...WITH ALL FORMS OF SEVERE WEATHER /VERY LARGE HAIL...DAMAGING
WINDS AND ISOLATED TORNADOES/ POSSIBLE IN ADDITION TO LOCALLY HEAVY
RAIN.
CONVECTION COULD START FAIRLY EARLY ON FRIDAY AS ANOTHER SUBTLE
SHORTWAVE TROUGH IS PROGGED TO ROTATE AROUND THE UPPER LOW AND
APPROACH THE SOUTH PLAINS REGION BY MIDDAY OR SO. RECENT NWP SUGGEST
THE DRYLINE WILL BE POSITIONED SOMEWHERE NEAR THE EDGE OF THE
CAPROCK TOMORROW AFTERNOON...SO THE HIGHEST SEVERE WEATHER
PROBABILITIES WILL BE ALONG AND EAST OF THIS LINE FRIDAY
AFTERNOON/EVENING...THOUGH LOCATIONS FURTHER WEST COULD SEE
CONVECTION EARLY IN THE DAY. THE DRYLINE SHOULD QUICKLY RETREAT
FRIDAY NIGHT AS THE FLOW BACKS IN RESPONSE TO THE APPROACHING UPPER
LOW. IT APPEARS THE MOISTURE COULD MAKE IT ALL THE WAY BACK TO
THE TX/NM LINE FOR A SHORT TIME EARLY SATURDAY BEFORE
STRENGTHENING LOW-LEVEL SOUTHWESTERLY FLOW SHUNTS THE MOISTURE
BACK EASTWARD. ALTHOUGH NWP SIGNALS ARE MIXED...WE WOULD EXPECT
CONVECTION TO ERUPT ALONG THE DRYLINE EARLY SATURDAY AS THE
STRONGEST UPPER LIFT GRAZES THE AREA. THE DRYLINE AND EARLY DAY
CONVECTION SHOULD THEN RACE EASTWARD AS THE DRIER SOUTHWEST WINDS
SPREAD FROM WEST TO EAST ACROSS THE FA. THE DRYLINE MAY MAKE IT
ALL THE WAY TO OR EVEN SLIGHTLY EAST OF THE CWA BY SATURDAY
EVENING...THOUGH WE HAVE MAINTAINED SLIM POPS ACROSS THE FAR
EASTERN ZONES GIVEN THE UNCERTAINTY. WEST OF THE DRYLINE BREEZY TO
LOW-END WINDY CONDITION WILL ENVELOP THE CAPROCK SATURDAY
AFTERNOON WHILE TEMPERATURES PEAK NEAR EARLY MAY AVERAGES.
THE DRY WESTERLY FLOW WILL PERSIST OVER MUCH OF THE AREA SUNDAY WITH
MODEST COOLING AS THE UPPER TROUGH AXIS APPROACHES FROM THE WEST.
THE ONE EXCEPTION COULD BE THE FAR SOUTHEAST ZONES AROUND ASPERMONT
WHERE THE LOW-LEVEL MOISTURE MAY LINGER NEARBY AND PROVIDE AT LEAST
A LOW RISK OF A STORM.
A COLD FRONT WILL FOLLOW THE TROUGH PASSAGE EARLY MONDAY PROVIDING
BELOW AVERAGE TEMPERATURES AND DRY CONDITIONS TO BEGIN NEXT WEEK.
MOISTURE WILL GRADUALLY RETURN THEREAFTER AND WE COULD SEE THE UPPER
RIDGE EARLY IN THE WEEK BEGIN TO BREAKDOWN AND PROVIDE A RETURN OF
LOW THUNDER CHANCES TO THE FORECAST TOWARD MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 78 49 80 48 / 20 20 10 20
TULIA 79 54 81 54 / 30 20 30 40
PLAINVIEW 79 55 81 54 / 30 30 30 40
LEVELLAND 82 56 83 56 / 20 30 20 50
LUBBOCK 80 58 84 58 / 30 30 30 40
DENVER CITY 82 54 83 53 / 20 20 20 50
BROWNFIELD 83 56 85 57 / 30 30 30 50
CHILDRESS 82 61 84 64 / 50 40 50 40
SPUR 81 57 84 63 / 50 40 50 40
ASPERMONT 84 61 86 66 / 50 40 50 40
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/23
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
328 AM CDT THU MAY 7 2015
.SHORT TERM /NOW THROUGH FRIDAY/...H5 TROF WILL SLIDE SOUTHWARD
ACROSS CALIFORNIA AND INTO THE DESERT SOUTHWEST. MID LEVEL RIDGE
WILL BE DRAPED ACROSS THE WESTERN GULF OF MEXICO AND A S/W TROUGH
OFF THE FLORIDA COAST. PERSISTENT SOUTHEASTERLY FLOW WILL CONTINUE
WITH SFC HIGH PRESSURE ACROSS THE NORTHEASTERN GULF OF MEXICO AND
LOW PRESSURE ACROSS THE HIGH PLAINS. BREEZY CONDITIONS WILL
CONTINUE THROUGH THE SHORT TERM PERIOD WITH GUSTS TO 25-30 MPH
POSSIBLE IN THE AFTERNOON HOURS. 850-700MB TEMPERATURES WARM
THROUGH THE PERIOD SO AN INCREASE AN AFTERNOON HIGHS UP INTO THE
LOWER 90S MIDDLE/UPPER VALLEY WITH UPPER 80S IN THE LOWER VALLEY
EACH DAY.
FOR PRECIPITATION CHANCES...HAVE SLIGHT CHANCE POPS THIS MORNING FOR
ANY ISOLATED SHOWER THAT HAPPENS TO DEVELOP UNDERNEATH THE STRONG
INVERSION /MUCH LIKE THE PAST SEVERAL DAYS/. MODELS ONCE AGAIN
PROG A WEAK DISTURBANCE MOVING ACROSS THE HIGHER TERRAIN THIS
AFTERNOON AND EVENING. HRRR AND GFS DEVELOP THUNDERSTORMS OVER THE
SIERRA MADRES THIS AFTERNOON AND MOVE EAST TOWARDS THE UPPER
VALLEY. WILL MAINTAIN SLIGHT CHANCE POPS OUT WEST THIS EVENING
THEN DECREASE OVERNIGHT AS CIN INCREASES RAPIDLY.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...THE APPROACH AND
PASSAGE OF A 500 MB TROUGH THROUGH THE TEXAS BIG BEND WILL ONCE
AGAIN INITIATE THUNDERSTORMS OVER THE NEIGHBORING HIGH TERRAIN OF
MEXICO...AND SOME OF THIS ACTIVITY MAY AFFECT THE BRO CWFA...
ESPECIALLY THE WESTERN THIRD AND NORTHERN HALF OF THE REGION.
STORM PREDICTION CENTER HAS A MARGINAL TO ENHANCED RISK OF SEVERE
WEATHER FOR MUCH OF TEXAS NORTH OF THE RIO GRANDE VALLEY AND DEEP
SOUTH TEXAS...SO SUCCESSIVE SHIFTS WILL HAVE TO MONITOR FOR THE
POSSIBILITY THAT SOME OF THIS STRONG TO SEVERE THUNDERSTORM
ACTIVITY MAY SNEAK INTO THE BRO CWFA FRIDAY NIGHT. AFTERWARDS...DRY
WEATHER WILL PREVAIL UNTIL ANOTHER POSSIBLE ROUND OF THUNDERSTORMS
OUT WEST SUNDAY NIGHT. A GREATLY ENHANCED OPPORTUNITY FOR RAINFALL
IS ANTICIPATED MONDAY THROUGH WEDNESDAY DUE TO THE INTRUSION AND
STALLING OF A WEAK COLD FRONT...A SOUTHWEST-TO-NORTHEAST 500 MB
FLOW OVERHEAD...AND THE FORMATION AND PERSISTENCE OF A SURFACE
TROUGH OF LOW PRESSURE WITHIN THE BRO CWFA. WITH DEEP TROPICAL
MOISTURE EXPECTED TO ALSO BE IN PLACE...WITH PRECIPITABLE WATER
VALUES AROUND 2 INCHES...THE POTENTIAL FOR LOCALLY HEAVY AND
FLOODING RAINFALL MAY EXIST MONDAY THROUGH WEDNESDAY. HOWEVER
...HAVE NOT INCLUDED THIS IN THE UPCOMING FORECAST AND WILL KEEP
AN EYE ON THE POTENTIAL FOR THIS HEAVY/FLOODING RAINFALL THROUGH
THE NEXT SEVERAL DAYS. NO MAJOR SURPRISES FOR THE TEMPERATURES...
NEAR TO SLIGHTLY ABOVE NORMAL THROUGHOUT THE ENTIRE LONG TERM
FORECAST PERIOD.
&&
.MARINE...NOW THROUGH FRIDAY...SEAS WERE NEAR 5 FEET WITH SOUTHEAST
WINDS NEAR 16 KNOTS AT BUOY020 THIS MORNING. MODERATE TO STRONG
SOUTHEAST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS TODAY AS
THE PRESSURE GRADIENT REMAINS STRONG ACROSS THE WESTERN GULF OF
MEXICO. WILL HAVE SCEC ACROSS ALL LOWER TEXAS COASTAL WATERS TODAY
AND GULF WATERS TONIGHT. FOR FRIDAY SCEC WILL BE NEEDED ACROSS ALL
LOWER TEXAS COASTAL WATERS ONCE AGAIN.
FRIDAY NIGHT THROUGH WEDNESDAY...SURFACE HIGH PRESSURE CENTERED
JUST SOUTH OF THE FLORIDA PENINSULA WILL INTERACT WITH PERSISTENT
LOW PRESSURE OVER THE CENTRAL PLAINS FROM FRIDAY NIGHT THROUGH
THE WEEKEND...PRODUCING SMALL CRAFT ADVISORY WINDS/SEAS ALONG THE
LOWER TEXAS COAST THROUGH THIS PERIOD. ALTHOUGH HIGH PRESSURE WILL
BECOME MORE IN CONTROL OVER THE WESTERN GULF OF MEXICO AFTERWARDS
...ROUGH SWELLS FROM THE EAST-SOUTHEAST TO SOUTHEAST WILL CONTINUE
THE CHANCE FOR SMALL CRAFT ADVISORY MONDAY THROUGH WEDNESDAY...
ESPECIALLY FOR THE FAR OFFSHORE GULF OF MEXICO WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 86 77 87 78 / 10 10 10 20
BROWNSVILLE 87 77 88 76 / 20 10 10 20
HARLINGEN 90 77 90 76 / 20 10 10 20
MCALLEN 91 77 92 77 / 20 10 10 20
RIO GRANDE CITY 91 76 93 76 / 20 20 10 20
SOUTH PADRE ISLAND 82 76 82 78 / 10 10 10 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...SCHOLL-55
LONG TERM...TOMASELLI-66
WX4PPT/MESO...BILLINGS-58
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
622 PM CDT FRI MAY 8 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 333 PM CDT FRI MAY 8 2015
A COLD FRONT WAS MOVING ACROSS NORTHEAST WISCONSIN THIS AFTERNOON.
MEANWHILE...LAKE BREEZE BOUNDARY DEVELOPED ACROSS KEWAUNEE AND
DOOR COUNTY. A FEW STORMS HAVE DEVELOPED ALONG THE BOUNDARY DURING
THE PAST HOUR. COLD FRONT WILL CONTINUE TO WORK ACROSS NORTHEAST
WISCONSIN FOR THE REMAINDER OF THE AFTERNOON...BRINGING A CHANCE
FOR MORE SHOWERS AND STORMS TO FORM...MAINLY BEFORE 7 PM.
ATTENTION THEN TURNS TO THE SYSTEM PASSING TO OUR SOUTH TONIGHT.
QUESTIONS STILL LINGER ON HOW FAR NORTH PRECIPITATION WILL MAKE
IT INTO OUR SOUTH. LEANED ON THE MESO MODELS AGAIN TONIGHT AND
THE 12Z REGIONAL CANADIAN MODEL THAT WOULD SUGGEST SOME RAIN
WOULD MAKE IT INTO MANITOWOC COUNTY.
LEANED TOWARD THE ADJMETBC GUIDANCE FOR MINIMUM TEMPERATURES
TONIGHT AND DID NOT STRAY FAR FROM PREVIOUS FORECAST FOR
MAXIMUM TEMPERATURES ON SATURDAY.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 333 PM CDT FRI MAY 8 2015
THE MODELS ARE IN DECENT AGREEMENT ABOUT LIFTING THE UPPER LOW
SLOWLY NORTHEAST FROM THE CENTRAL PLAINS TO WISCONSIN OR UPPER
MICHIGAN SUNDAY NIGHT THROUGH TUESDAY MORNING. THEY DIFFER IN THE
TRACK OF THE SURFACE LOW AND PLACEMENT OF PRECIPITATION BUT FOR
THE MOST PART HAVE PERIODS OF RAIN AND SOME ELEVATED THUNDERSTORMS
SUNDAY NIGHT THROUGH MONDAY NIGHT WITH LEFTOVER SHOWERS TUESDAY
ESPECIALLY IN THE NORTH WHERE BOUNDARY LAYER TEMPERATURES MAY BE
COLD ENOUGH FOR SOME SNOW TO BE MIXED IN. COOLER AND DRIER AIR
WILL ARRIVE FOR THE TUESDAY NIGHT THROUGH THURSDAY WITH THE
POSSIBILITY OF A FROST OR FREEZE TUESDAY AND WEDNESDAY NIGHT.
UPPER HEIGHTS ARE FORECAST TO RISE TOWARDS THE END OF THE WEEK
WITH MILDER WEATHER AND A CHANCE OF SHOWERS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 615 PM CDT FRI MAY 8 2015
MAIN AVIATION FCST ISSUE THE NEXT 12-18 HRS WL BE CIGS. CURRENT
LOW DECK ACRS THE AREA IS DECRG. CLD DECK TO THE N OF LAKE
SUPERIOR IS QUITE CELLULAR LOOKING...INDICATING IT ALSO IS LIKELY
TO GO AWAY OR AT LEAST DECREASE SUBSTANTIALLY AFTER SUNSET. THERE
IS HOWEVER A BAND OF CLDS WITH BASES IN THE 2.5-3.5K FT LAYER FM
KIWD NEWD ACRS LAKE SUPERIOR AND INTO ONTARIO THAT APPEARS TO BE
EXPANDING. LAV GUIDANCE AND FCST SOUNDINGS OFF THE RAP AND HRRR
QUITE INSISTENT LOW CLDS WL REDEVELOP/EXPAND ACRS THE FCST AREA
DURING THE NGT. THAT WAS THE TACT TAKEN WITH THE 18Z TAFS...AND WL
HOLD ONTO THAT FOR 00Z ISSUANCE WITH THE EXPECTATION THAT THE CLD
BAND OVER LAKE SUPERIOR WL SHIFT SWD AND EXPAND. BUT THIS IS NOT A
HIGH CONFIDENCE FCST...AND ADJUSTMENTS MAY BE NEEDED LATER THIS
EVENING OR WITH THE NEXT ISSUANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ECKBERG
LONG TERM......RDM
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
324 PM CDT THU MAY 7 2015
.TONIGHT...FORECAST CONFIDENCE MEDIUM.
SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED ALONG THE WI/IA BORDER
WITH SOME WEAK SHORTWAVE ENERGY THIS MORNING AND ARE SLOWLY TRACKING
EAST INTO SOUTH CENTRAL WI THIS AFTERNOON. THEY ARE WEAK SINCE THEY
ARE ENCOUNTERING A WELL-MIXED... DRY AND CAPPED ENVIRONMENT.
THE NEXT CHALLENGE IS EVENING AND OVERNIGHT PRECIP CHANCES. THE
MAJORITY OF MODELS ARE SHOWING A DRY FORECAST FOR SOUTHERN WI THIS
EVENING AS SOON AS THE ONGOING SHOWERS DISSIPATE. THERE IS AN AREA
OF SHOWERS AND THUNDERSTORMS DEVELOPING ALONG ANOTHER SHORTWAVE OVER
NORTHEAST MO THIS AFTERNOON THAT SHOULD TRACK EAST OR NORTHEAST
THROUGH THE EVENING. THE HRRR MODEL IS THE ONLY MODEL THAT IS
CONSISTENTLY DEVELOPING A LARGE PRECIP SHIELD WITH THAT CONVECTION
AND BRINGING IT INTO SOUTHERN WI. THEREFORE... WENT WITH JUST SLIGHT
CHANCES FOR SHOWERS AND THUNDERSTORMS THIS EVENING.
THE OVERNIGHT WEATHER SHOULD BE QUIET ACROSS SOUTHERN WI. THERE IS
NOT MUCH SUPPORT FOR SHOWER/TSTORM DEVELOPMENT. KEPT SCHC POPS...BUT
THIS MAY BE ABLE TO BE REMOVED.
FRIDAY... FORECAST CONFIDENCE MEDIUM.
A WEAK COLD FRONT WILL SLIDE SOUTHEAST THROUGH SOUTHERN WI ON
FRIDAY. THIS MAY TRIGGER SOME THUNDERSTORMS AS IT REACHES SOUTHEAST
WI FRIDAY AFTERNOON. KEPT THE LIKELY POPS FOR THIS AREA. MODEL
SOUNDINGS SHOW A GOOD AMOUNT OF CAPE BUT WEAK SHEAR... SO NOT
EXPECTING SEVERE STORMS.
TEMPERATURES WILL BE WARM ONCE AGAIN AHEAD OF THIS FRONT ON FRIDAY.
EXPECT A LAKE BREEZE TO DEVELOP IN THE EARLY AFTERNOON ONCE AGAIN.
.FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
A SURFACE COLD FRONT WILL BE WORKING THROUGH THE AREA DURING THE
EVENING...BUT THE MODELS ARE ALL OVER THE PLACE WITH
TIMING. THE GFS HAS IT EXITING KENOSHA RIGHT AROUND 00Z SAT...
WHILE THE ECMWF IS STILL BACK OVER MADISON OR JUST NW OF MADISON.
THE NAM IS IN BETWEEN. ALL THE MODELS SHOW A WEAK MID LEVEL WAVE
ROLLING UP HERE IN THE DEEP SOUTHWEST FLOW AT THAT TIME. GIVEN
THAT THE FLOW IS SOUTHWEST...WILL DISCARD THE FAST GFS AS A FASTER
SOLUTION ISN/T TYPICAL WITHOUT ENCOURAGEMENT ALOFT. WE BUILD SOME
CAPE IN THE AFTERNOON...SO WILL KEEP THE LIKELY POPS ACROSS THE
SOUTHEAST WITH FROPA AND THE MID LEVEL WAVE COMBO.
NORTH TO NORTHEAST WINDS IN THE WAKE OF THE FRONT WILL COOL DOWN
THE LAKE SHORE AREAS SIGNIFICANTLY BY MORNING.
.SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE COLD FRONT WILL BE SOUTH OF US BY SUNRISE SATURDAY MORNING
WITH A COOLER AND DRIER NORTHEAST TO EAST FLOW OVER ALL OF
SOUTHERN WISCONSIN. IF YOU/RE HEADED OVER TOWARD LAKE
MICHIGAN...IT WILL BE CHILLY. THE UPPER FLOW REMAINS SOUTHWEST ON
SATURDAY AND THE MODELS STILL SHOW SOME SHORT WAVE ENERGY
POTENTIALLY ROLLING UP HERE. HOWEVER...THE COLUMN WILL BE PRETTY
DRY AND THE BEST LOW LEVEL FORCING WILL BE WELL SOUTH. HOWEVER...
WILL HANG ONTO A SMALL CHANCE OVER THE FAR SOUTH IN CASE ANY
SHOWERS SNEAK FARTHER NORTH.
RAIN CHANCES WILL INCREASE SATURDAY NIGHT AS A STRONG UPPER LOW
BEGINS TO DEVELOP OVER THE CENTRAL PLAINS AND WE GET INTO A
STRENGTHENING SOUTHERLY FLOW...AT LEAST ABOVE THE BOUNDARY LAYER.
THE 850MB WARM FRONT SHOULD GET INTO SOUTHERN WISCONSIN AND THIS
COULD A FOCUS FOR ELEVATED SHOWERS AND POSSIBLE THUNDERSTORMS.
THE WARM AIR ADVECTION IS MODEST.
.SUNDAY INTO MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE STRONG...CLOSED UPPER LOW IS PROGGED TO BE OVER WRN NEB
SUNDAY MORNING AND MOVING VERY SLOWLY TO SOUTHERN MN BY MONDAY
EVENING...BECOMING AN OPEN TROF BY THAT TIME. THIS PUTS US IN A
PERSISTENT SOUTHERLY FLOW WITH THE USUAL TIMING ISSUES RELATED TO
SHORT WAVE IMPULSES ROLLING NORTH AHEAD OF THE UPPER LOW. THE SFC
COLD FRONT LOOKS LIKE IT MAY STAY SOUTH OF WISCONSIN THROUGH THE
DAY ON SUNDAY...BUT THE 850MB BOUNDARY WILL BE WELL NORTH. GIVEN
THE STRENGTHENING UPPER LEVEL DIVERGENCE AND LOW LEVEL JET...IT
LOOKS LIKE SHOWERS AND STORMS WILL BE LIKELY SUNDAY. THE CHANCES
INCREASE SUNDAY NIGHT AS THE SURFACE FRONT LIFTS NORTH. CAN/T RULE
OUT SEVERE WEATHER...BUT THE BETTER CAPE STAYS TO OUR SOUTH
THROUGH SUNDAY NIGHT.
MONDAY IS LOOKING INTERESTING AS THE STACKED LOW MOVES NORTHEAST
INTO THE SOUTHERN MN VCNTY. TIMING IS KEY HERE...AS ALWAYS. THERE
IS A SMALL WINDOW OF OPPORTUNITY FOR STRONG/SEVERE WEATHER...BUT
IT LOOKS LIMITED TO MAINLY THE EASTERN PORTION OF THE FORECAST
AREA. A NARROW BAND OF HIGHER CAPE AND SHEAR SHOULD DEVELOP AHEAD
OF AN ADVANCING COLD FRONT. THE MID LEVEL WESTERLIES AND LOW LEVEL
SOUTHERLY JET WILL ALSO INCREASE CONSIDERABLY INTO SOUTHERN
WISCONSIN. BUT THIS COULD ALL PUSH EAST BEFORE THE FAVORABLE
DIURNAL MAX...OR STAY FOCUSED JUST TO OUR SOUTH...KEEPING US ON
THE MORE STABLE SIDE OF THINGS. LOTS OF UNCERTAINTY...BUT THERE IS
LOTS OF ENERGY MOVING THROUGH THE UPPER MIDWEST.
.TUESDAY AND WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
HIGH PRESSURE WILL BUILD IN FOR MID WEEK. WE MIGHT SEE SOME
SHOWERS ON TUESDAY...BUT THAT CHANCE IS PRETTY SMALL AT THIS
POINT. THE RIDGE WILL BE OVERHEAD ON WEDNESDAY...SO QUIET AND
COOL.
&&
.AVIATION/00Z TAFS/...
UNCERTAINTY WITH THUNDERSTORM CHANCES FOR THE NEXT 30 HOURS... BUT
IT LOOKS LIKE SOUTHEAST WI WILL HAVE THE BEST CHANCE FRIDAY
AFTERNOON ALONG A COLD FRONT TRACKING SOUTHEAST THROUGH THE STATE.
THERE ARE SOME INDICATIONS FOR FOG AND LOW CLOUDS TO DEVELOP OVER
PORTIONS OF CENTRAL WI DUE TO A WEAK PRESSURE GRADIENT WITH A
SURFACE TROUGH AND INVERSION EARLY FRIDAY MORNING. LOWEST CEILINGS
SHOULD BE NORTHWEST OF MADISON... BUT MVFR VSBY IS POSSIBLE ACROSS
ALL OF SOUTHERN WI.
&&
.MARINE...
MARINE FOG MOSTLY DISSIPATED OVER SOUTHERN LAKE MICHIGAN TODAY BUT
IT COULD REDEVELOP TONIGHT WITH WARM AND MOIST AIR LINGERING OVER
THE AREA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...MRC
FRIDAY NIGHT THROUGH THURSDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1048 AM CDT THU MAY 7 2015
.UPDATE...
DENSE FOG MOVED OUT OF THE NEARSHORE WATERS... PER WEBCAMS AND
VISIBLE SATELLITE IMAGERY. MID AND HIGH CLOUDS ARE STREAMING NORTH
ACROSS SOUTHERN WI THIS MORNING. WINDS ARE BEGINNING TO INCREASE AS
THE STRONG WINDS ALOFT MIX DOWN TO THE SURFACE. DEWPOINTS SHOULD
STAY MIXED AND IN THE 50S TODAY. TEMPERATURES ARE ON TRACK TO REACH
THE LOWER 80S TODAY... INCLUDING THE LAKESHORE COUNTIES. THERE WILL
BE PLENTY OF SUNSHINE... BUT IT WILL BE BREEZY WITH WIND GUSTS UP TO
30 MPH.
THERE IS STILL A CHANCE FOR SHOWERS TO TRACK INTO SOUTH CENTRAL WI
THIS AFTERNOON. THE 12Z NAM AND CANADIAN MODELS CAME IN WITH A
SIMILAR SOLUTION AS THEIR PREVIOUS RUNS THAT SHOW PRECIP TRACKING
ACROSS MUCH OF THE AREA PRIOR TO 00Z DUE TO A SHORTWAVE. THE HRRR
AND RAP MODELS HAVE A DRY FORECAST FOR SOUTH CENTRAL WI THIS
AFTERNOON AS OF RIGHT NOW... BUT THEY ARE NOT PICKING UP ON THE
SHOWERS DEVELOPING ALONG THE WI/IOWA BORDER AS OF 1030 AM. ANY
SHOWERS/TSTORMS MOVING INTO THE AREA WILL ENCOUNTER A WELL-MIXED...
DRY AND CAPPED ENVIRONMENT. THIS WILL LEAD TO DECAYING SHOWERS AS
THEY MOVE ENE.
&&
.AVIATION/18Z TAFS/...
A VFR PERIOD IS EXPECTED WITH ISOLD TO SCT THUNDER A BETTER
OVERNIGHT THREAT IN THE KMSN AREA...POSSIBLY REACHING ERN TAF SITES
LATE TNGT INTO FRI MRNG.
&&
.MARINE...
VEERING WINDS TO THE SOUTH TO SOUTHEAST WILL RESULT IN WIND GUSTS
APPROACHING SMALL CRAFT ADVY LEVELS THIS AFTERNOON. THEY ALSO LED
TO MARINE FOG SHIFTING WELL OFF SHORE AND NORTHWARD THIS MORNING.
THUS... THE MARINE DENSE FOG ADVISORY WAS CANCELLED.
&&
.PREV DISCUSSION... /ISSUED 354 AM CDT THU MAY 7 2015/
TODAY AND TONIGHT... FORECAST CONFIDENCE - MEDIUM.
FORECAST FOCUS ON MORNING FOG...WARM TEMPERATURES AND INCREASING
THUNDER THREAT. BOUNDARY LAYER WINDS HAVE STEADILY INCREASED
OVERNIGHT AND SHIFTED MORE TO THE SOUTH. RECENT DESCENT TAMDAR
SOUNDING INTO KMKE SHOWS SOUTH WINDS AT 24KTS ONLY 1800 FT OFF
GROUND. DENSE FOG HAS THINNED RAPIDLY IN LAST SEVERAL HOURS OVER
MOST OF EASTERN CWA. SOME LIGHTER FOG WL LIKELY CONTINUE INTO THE
EARLY MORNING DUE TO PERSISTENT LIGHT E WINDS AT THE SFC...BUT
EXPECT INSOLATION AND INCREASING SFC WINDS TO ERASE ALL FOG BY MID-
MORNING.
FOCUS OF CONVECTION TODAY REMAINS TO THE WEST IN THE PLAINS WHERE
WEAKENING MID-LEVEL TROF WILL BE NUDGED NORTHEAST BY UPPER LOW
SLIDING SOUTH ACROSS WESTERN CONUS. WILL KEEP MOST OF MORNING DRY
AND WITH AT LEAST PARTIAL SUNSHINE AND INCREASE SOUTH
WINDS...TEMPERATURES WILL RISE WELL INTO THE 70S...PEAKING IN THE
LOWER 80S IN THE AFTN. THE WARMER AIR WILL BE WELCOME CLOSER TO THE
LAKESHORE AS 925H TEMPS WARM TO AROUND 20C. LOCATIONS RIGHT ALONG
THE LAKESHORE WILL REMAIN A BIT COOLER...ESPECIALLY WIND POINT AND
NORTHERN OZAUKEE INTO SHEBOYGAN COUNTIES AS SFC WINDS WL REMAIN
SOUTH TO SOUTHEAST THIS AFTN.
WHILE MAIN SHORT WAVE TRAVELS NORTHEAST ACROSS NORTHERN
PLAINS...WEAKER UPSTREAM WAVE CURRENTLY OVER THE KS/MO AREA WILL
TRACK NORTHEAST ACROSS IOWA INTO CENTRAL WI TODAY INTO THIS EVENING.
PROTECTIVE RIDGE HAS MOVED OFF TO THE EAST...SO WITH DEEPER MOISTURE
IN THE AREA...THINKING SCATTERED -SHRA AND -TSTM WILL AFFECT WESTERN
CWA LATER THIS AFTN AND EVE. MUCAPE INCREASES TO 500 TO 1000 J/KG
IN THE WEST DURING THIS PERIOD...BUT STRONGEST CONVECTION TO REMAIN
TO THE WEST. 6KM SHEAR DOES INCREASE TO 25 TO 30 KTS SO NOT
IMPOSSIBLE ONE OR TWO STORMS TURN MORE RAMBUNCTIOUS NEAR NORTHWEST
CWA.
WEAKENING TROF AND FRONTOGENETICAL FORCING SLIDES ACROSS WI TONIGHT
AS COOL FRONT SLIDES INTO CENTRAL WI. WL CONTINUE LOWER POPS FOR
THE LATE NIGHT AND SPREAD CHANCE INTO ERN CWA.
FRIDAY AND FRIDAY NIGHT - CONFIDENCE...MEDIUM
500 MILLIBAR FLOW REMAINS SOUTHWEST WITH SURFACE/850 FRONTS
ENHANCING LOW LEVEL CONVERGENCE THIS PERIOD. IN ADDITION...250
MILLIBAR JET AND RIGHT REAR CONTRIBUTIONS SUGGEST FORCING WILL BE
ENHANCED WELL INTO THE EVENING HOURS SUPPORTING THE SLOWER FROPA
AND LINGERING SHRA/TSRA POTENTIAL PER ECMWF/NAM. GFS STILL PRETTY
QUICK ON EXITING PRECIP DURG THE EVE IN THE SE CORNER OF THE CWA.
NAM SOUNDINGS SHOW CAPE VALUES PUSHING 1000 J/KG.
SATURDAY - CONFIDENCE...MEDIUM
MID LEVEL FLOW REMAINS SOUTHWEST AND MODELS DO SHOW SOME VORT
ACTION IN THIS REGIME. SURFACE FRONT PROGGD TO BE SOUTH OF WI WITH
COOLER AND MORE STABLE NE SFC WIND. SFC RIDGING NUDGES SOUTH INTO
SRN WI. NEVERTHELESS SOME WEAK ISENTROPIC ASCENT COMBINED WITH
LINGERING UPPER DIVERGENCE AND EMBEDDED WAVES IN SOUTHWEST
FLOW...WILL KEEP SHRA CHCS GOING.
SUNDAY - CONFIDENCE...MEDIUM
UPPER LOW WILL BE LIFTING SLOWLY NORTHEASTWARD FROM THE CENTRAL
PLAINS. SUBSEQUENT SURFACE LOW DEVELOPMENT WILL TAKE SHAPE ACROSS
NEBRASKA. SURFACE BOUNDARY REMAINS DRAPED TO THE SOUTH OF WI. WITH
INCREASING SOUTHERLY 850 FLOW...THIS WILL ENHANCE ISENTROPIC LIFT
VICINITY 850 BAROCLINIC ZONE...SO POPS RISE TO THE LIKELY
CATEGORY. EASTERLY FLOW IS MAINTAINED THUS A COOL REGIME PERSISTS.
SUNDAY NIGHT AND MONDAY - CONFIDENCE...MEDIUM
UPPER LOW IN THE PLAINS PROGGD TO OPEN UP AND PROGRESS EAST WITH
PIECES OF NEGATIVELY TILTED SHORTWAVE ENERGY RIDING THROUGH DURING
THE PERIOD. SURFACE LOW OCCLUDES AND PLODS ACROSS SRN/CNTRL WI
VCNTY ON MONDAY. WILL HAVE HIGH POPS...WITH MODELS SHOWING HIGHEST
PRECIP POTENTIAL IN THE 6-18Z TIME FRAME. HIGHEST CWASP VALUES OF
60 TO 70 NOTED BEFORE 18Z WITH AXIS OF HIGHER PARAMETERS SHIFTING
EAST BY 00Z.
MONDAY NIGHT AND TUESDAY - CONFIDENCE...MEDIUM
AS SURFACE LOW PULLS AWAY...LOW LEVEL COLD ADVECTION WRAPS IN.
MID LEVEL FLOW REMAINS CYCLONIC WITH LOW LEVEL TROUGH AXIS HANGING
BACK AS WELL...SO WILL KEEP THE SUPERBLEND POPS FOR SHRA CHCS.
WEDNESDAY - CONFIDENCE...LOW
ECMWF SHOWS A QUICKER WAA RESPONSE AS NEXT LOW MOVES INTO THE PLAINS
WHILE THE GFS MODIFIES THE THERMAL TROUGH BUT KEEPS NORTHWEST 850
FLOW IN PLACE. ECMWF GENERATES QPF INTO NW WI WITH THE GFS DRY AND
NO SIGN OF AN APPROACHING LOW. WILL GO WITH THE DRY LOOK AT THIS
POINT AND EXPECT SOME MODIFICATION IN TEMPS FROM TUESDAY.
AVIATION/12Z TAFS/...INCREASING BOUNDARY LAYER WINDS JUST ABOVE SHALLOW
INVERSION OVERNIGHT HAS CAUSED THE DENSE FOG TO THIN. ONLY EXPECT PATCHY
LIGHT FOG INTO THE EARLY MORNING BEFORE COMPLETELY THINNING. THEN
A VFR PERIOD IS EXPECTED WITH ISOLD TO SCT THUNDER A BETTER OVERNIGHT
THREAT IN THE KMSN AREA...POSSIBLY REACHING ERN TAF SITES LATE TNGT
INTO FRI MRNG.
MARINE...BOUNDARY LAYER WINDS HAVE INCREASED OVERNIGHT TO THIN THE
DENSE FOG OVER MOST OF THE INLAND AREAS. HOWEVER LIGHT EAST TO SOUTHEAST
FLOW THIS MORNING AND WARM...HUMID AIR OVER THE COOL LAKE MI WATERS
SHOULD CONTINUE TO TRIGGER AREAS OF DENSE FOG OVER THE NEAR SHORE
WATERS. 11-3.9 MICRON IMAGERY SHOWS AREAS OF FOG LINGERING OVER
LAKE MI EARLY THIS MRNG. HENCE WILL CONTINUE DENSE FOG ADVY THRU
MOST OF THE MORNING.
WILL GET BETTER IDEA OF DENSE FOG EXTENT WITH NEW VSBL IMAGERY
AVAILABLE AFT 13Z.
VEERING WINDS TO THE SOUTH TO SOUTHEAST WILL RESULT IN WIND GUSTS
APPROACHING SMALL CRAFT ADVY LEVELS DURING THE AFTN. FOR NOW WL
COUNT ON SLIGHT ONSHORE COMPONENT OVER NEAR SHORE WATERS TO CONTINUE
SHALLOW LOW LEVEL INVERSION...PREVENTING STRONGER WINDS FROM MIXING
TO SURFACE. WL MENTION IN HWO.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1201 PM MDT THU MAY 7 2015
.UPDATE...
ISSUED AT 1159 AM MDT THU MAY 7 2015
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
WYDOT WEBCAMS CONTINUE TO INDICATE PATCHY FOG OVER THE INTERSTATE 80
SUMMIT AND ADJACENT FOOTHILLS EARLY THIS AM. PERSISTENT LLVL UPSLOPE
AND ABUNDANT BOUNDARY LAYER MOISTURE SHOULD REMAIN IN PLACE THROUGH
MID MORNING...SO EXPECT THIS TO CONTINUE FOR A FEW MORE HOURS. HAVE
NOT SEEN ANYTHING PARTICULARLY DENSE...SO DO NOT SEE ANY NEED FOR A
DENSE FOG ADVISORY AT THIS TIME. THE HRRR SHOWS LOCALLY REDUCED VSBY
TO AROUND ONE QUARTER OF A MILE THROUGH 15Z...THEN DISSIPATING. THIS
SEEMS TO MAKE SENSE WITH MOISTURE PROFILES ON BUFKIT SOUNDINGS. KCYS
RADAR LOOP SHOWS SHOWER ACTIVITY WINDING DOWN OVER FAR SOUTHEAST WY
INTO THE SOUTHERN NE PANHANDLE. THE NAM SHOWS WINDS SHIFTING TO THE
EAST/NORTHEAST AFTER 18Z AS A MID LEVEL DISTURBANCE MOVES OUT OF CO
AROUND THE SAME TIME. THIS FRAGMENTED WAVE WAS OBSERVED AT 12Z PER
RECENT WATER VAPOR IMAGERY. QPF SIGNALS INCREASE DRAMATICALLY DURING
THE AFTERNOON WITH THE RETURN OF EXCELLENT UPSLOPE...SO RAIN COULD
VERY WELL BECOME WIDESPREAD AGAIN LATER TODAY FROM THE HIGH COUNTRY
EASTWARD INTO CHEYENNE. PWAT VALUES REMAIN RESPECTABLE AROUND 0.5 TO
0.6 INCH...SO FELT COMFORTABLE BRINGING LIKELY POPS BACK INTO THE
PICTURE DURING THE LATE AFTN/EARLY EVE. THE NAM AND GFS BOTH SHOW A
RIBBON OF 500 J/KG SBCAPES ALONG THE I80 CORRIDOR IN OUR CWA...SO AT
LEAST A FEW LIGHTNING STRIKES ARE POSSIBLE. LIMITING FACTOR FOR ANY
AVAILABLE INSTABILITY WILL BE COOLER TEMPERATURES WITH UPSLOPE AND
RESULTING CLOUD COVER. THUNDERSTORMS COULD PRODUCE HAIL IN THIS TYPE
OF ENVIRONMENT IF THE MODELS VERIFY.
THINGS START TO GET INTERESTING ON FRIDAY AS A VIGOROUS LATE SEASON
WINTER STORM BEGINS TO TAKE SHAPE. WE ARE INDEED DEALING WITH A VERY
CHALLENGING FORECAST WITH RESPECT TO SNOW LEVELS AND RESULTING SNOW
AMOUNTS...AS WELL AS IMPACTS TO TRAVEL FOR MOTHERS DAY. GFS/NAM/ECM
ARE ALL IN EXCELLENT AGREEMENT WITH A VIGOROUS CLOSED LOW OVER THE
GREAT BASIN AT 12Z FRI. THIS FEATURE SLOWLY MEANDERS INTO THE FOUR
CORNERS REGION BY 06Z SAT WITH SURFACE CYCLOGENESIS RAMPING UP OVER
SOUTHEAST CO. ALL OF THE MODELS SHOW THIS SYSTEM LIFTING NORTHEAST
ON SAT NIGHT AND SUN WITH THE ASSOCIATED SUB-1000 MILLIBAR SURFACE
LOW SHIFTING INTO NORTHWEST KS. THIS TRACK ALLOWS MUCH COOLER AIR TO
SPILL INTO OUR HIGHER ELEVATION AREAS AS EARLY AS FRI NIGHT...WITH
H7 TEMPS FALLING TO -2C BY 12Z SAT. NAM WBZ HEIGHTS FALL TO AROUND
8000 FEET OR SO BY 09Z...AND FORECAST SOUNDINGS OVER THE SUMMIT ARE
FULLY SUPPORTIVE OF SNOW WHICH COULD BE HEAVY GIVEN A LAYER OF DEEP
SATURATION. A FEW PIECES OF ENERGY ROUNDING THE LOW WILL SUPPORT AN
INCREASE IN PCPN DURING THIS TIME...SO DO EXPECT THIS TO BE THE VERY
BEGINNING OF A POTENTIALLY SIGNIFICANT WINTER STORM EVENT. SLIGHTLY
NEGATIVE EPV VALUES SUGGEST ENOUGH INSTABILITY FOR A FEW CONVECTIVE
ELEMENTS AS WELL...FURTHER REINFORCING THE LIKELIHOOD OF SNOW.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
VERY CONCERNED THAT TRAVEL CONDITIONS MAY QUICKLY DETERIORATE BY SAT
MORNING...EVEN THOUGH THE MAIN SNOWFALL EVENT IS NOT EXPECTED UNTIL
LATER IN THE DAY ON SAT. THIS WOULD MAINLY BE OVER THE I80 SUMMIT...
BUT THIS AREA HAS BEEN A PROBLEM RECENTLY WITH VERY SIMILAR SYNOPTIC
SETUPS. WITH EARLY IMPACTS AND LIKELIHOOD OF MAJOR ACCUMULATIONS ON
SAT...WE DECIDED TO GO WITH A WINTER STORM WATCH FOR ALL OF OUR MTN
ZONES BEGINNING AT 06Z SAT. CONCERNING THE LATER EVOLUTION OF THIS
EVENT...NOTABLE COLD ADVECTION ALOFT APPEARS LIKELY ON SAT WITH H7
TEMPS FALLING TO BETWEEN -5 AND -10 DEG C ACROSS THE ENTIRE CWA BY
12Z SUN. THIS ULTIMATELY ALLOWS SNOW LEVELS TO FALL TO 5000 FEET OR
LOWER DURING THE COURSE OF THE EVENT. THE TRICKY PART WILL BE TIMING
WHEN THIS OCCURS FROM W TO E. ESPECIALLY CONCERNED ABOUT CHEYENNE AS
THE EUROPEAN SHOWS A DISTINCT COLD AIR DAMMING SIGNATURE DRAPED OVER
THE CO FRONT RANGE. THAT WAS OUR ACHILLES HEEL WITH THE LAST CLOSED
LOW WE DEALT WITH...AND IT KEPT WINDS NORTHERLY AT KCYS WITH COLDER
TEMPERATURES THAN MODELS PROGGED. THIS HAS BEEN THE ONLY MODEL TO
SHOW THIS SO FAR...BUT CAUTIOUSLY TRENDED LOWER ON TEMPS. THIS COULD
CAUSE SNOWFALL AMOUNTS TO BE SIGNIFICANTLY HIGHER AS THE HEAVIER
PCPN COULD VERY WELL BEGIN AS SNOW. WILL MAINTAIN A 6-10 INCH FCST
LOCALLY...BUT THIS MAY NEED TO BE REVISED. LATER SHIFTS WILL MOST
LIKELY NEED TO EXPAND THE WATCH EASTWARD INTO THE PLAINS. SHOULD
ALSO NOTE THAT GFS/SREF/NAM SOUNDINGS ALL SHOW A SUB-ZERO THERMAL
PROFILE AT LUSK ALL DAY ON SAT...SO COULD SEE SOME LOCALLY HIGHER
AMOUNTS IN THE HIGHER TERRAIN OUT THERE.
QPF SIGNALS FROM ALL MODELS ARE SCARY TO SAY THE LEAST. BUT ALAS...
THEY ARE BELIEVABLE WITH IMPRESSIVE MOISTURE (0.5 INCH PWATS FOR A
WINTER EVENT) COMBINED WITH EXCELLENT DYNAMIC SUPPORT BENEATH VERY
DIFLUENT FLOW AND A COUPLED UPPER JET. ALSO SEEING SOME INSTABILITY
IN THE MIX TOO WHICH WILL LIKELY LEAD TO MESOSCALE BANDING. NAM IS
STILL THE OUTLIER WITH THE HEAVIER PCPN DISPLACED WELL TO THE EAST
OF OUR CWA. GFS/ECMWF HAVE BEEN VERY CONSISTENT WITH WIDESPREAD 2-4
INCH LIQUID AMOUNTS...ESPECIALLY ALONG/EAST OF THE LARAMIE RANGE
WITH SIGNIFICANT UPSLOPE EXPECTED. THE NEW SREF IS TAGGING ALONG AS
WELL WITH HIGHER-END AMOUNTS. THAT SAID...CONFIDENCE IS VERY HIGH
THAT WE WILL SEE A SIGNIFICANT PRECIPITATION EVENT. WITH FORECAST
SOUNDINGS AS COLD AS THEY ARE...A FAIR AMOUNT OF THIS WILL PROBABLY
FALL AS SNOW. COULD SEE SEVERAL FEET IN THE MOUNTAINS. IT IS NOT
OUTSIDE OF THE REALM OF POSSIBILITY TO SEE A FOOT OR MORE FALL IN
CHEYENNE EITHER...BUT NEED TO SEE A FEW MORE MODEL RUNS TO BE SOLD
ON THAT SCENARIO. STAY TUNED AS THIS STORM APPEARS LIKELY TO GIVE US
QUITE A PUNCH. SNOW SHOULD FINALLY BEGIN TO DIMINISH BY SUN AFTN
AND/OR NIGHT AS THE LOW LIFTS INTO THE CENTRAL AND NORTHERN
PLAINS.
WITH THE LOW PRESSURE SYSTEM OPENING UP AND LIFTING OUT TO THE
NORTHEAST MONDAY...WE HAVE SOME LINGERING LIGHT SNOW SHOWERS IN
THE FORECAST FOR EARLY MONDAY MORNING...THEN WE SEE A CLEARING
AND WARMING TREND GOING THROUGH MIDWEEK. A RETURN OF DIURNAL
SHOWER/THUNDERSTORM CHANCES IS IN THE FORECAST BY LATE NEXT WEEK
AS WE SEE A NORTHWESTERLY FLOW ALOFT ON THE NORTHEAST SIDE OF A
4-CORNERS UPPER RIDGE. LOOKING JUST BEYOND THE 7 DAY FORECAST...
MODELS ARE SUGGESTING A MUCH WARMER AND DRIER WEEKEND FOR NEXT
WEEK.
&&
.AVIATION.../18Z ISSUANCE/
MOIST...UNSTABLE ATMOSPHERE THIS AFTERNOON AND EVENING. WILL
CONTINUE TO MAKE MENTION OF THUNDER...ESPECIALLY OVER AND SOUTH
OF I-80. BRIEF HEAVY RAIN LIKELY WITH ANY STORMS SOUTHEASTERLY
FLOW AT THE SURFACE THROUGH TONIGHT WITH REDEVELOPMENT OF MVFR TO
IFR CONDITIONS AT MOST LOCATIONS. FOG WILL BE MAIN THREAT WITH
AREAS OF LIGHT RAIN OR DRIZZLE. CIELINGS SHOULD ONCE AGAIN LIFT
MID TO LATE MORNING ON FRIDAY.
&&
.FIRE WEATHER...
ISSUED AT 526 AM MDT THU MAY 7 2015
THE COOL AND WET WEATHER PATTERN WILL CONTINUE THROUGH THE
WEEKEND...WITH FAIRLY HIGH CHANCES FOR MEASURABLE RAINFALL OR
SNOW. A STRONG STORM SYSTEM WILL IMPACT THE DISTRICTS THIS WEEKEND
WITH POTENTIALLY WIDESPREAD AND HEAVY PRECIPITATION AMOUNTS...AS
WELL AS GUSTY NORTHERLY WINDS. THIS SYSTEM WILL BE COLD
ENOUGH...WITH SNOW LEVELS DROPPING TO AROUND 5000 FEET. MINIMUM
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE FORECAST PERIOD. A TREND TOWARD WARMER AND
DRIER CONDITIONS WILL COMMENCE BY TUESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY
AFTERNOON FOR WYZ103-112-114-116.
NE...NONE.
&&
$$
UPDATE...WFOCYS
SHORT TERM...CLH/JG
LONG TERM...CLH
AVIATION...WFO CYS
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
526 AM MDT THU MAY 7 2015
...A STRONG WINTER STORM SYSTEM WITH HEAVY SNOW FOR SOUTHEAST WYOMING
CONTINUES TO TAKE SHAPE FOR THIS WEEKEND...
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
WYDOT WEBCAMS CONTINUE TO INDICATE PATCHY FOG OVER THE INTERSTATE 80
SUMMIT AND ADJACENT FOOTHILLS EARLY THIS AM. PERSISTENT LLVL UPSLOPE
AND ABUNDANT BOUNDARY LAYER MOISTURE SHOULD REMAIN IN PLACE THROUGH
MID MORNING...SO EXPECT THIS TO CONTINUE FOR A FEW MORE HOURS. HAVE
NOT SEEN ANYTHING PARTICULARLY DENSE...SO DO NOT SEE ANY NEED FOR A
DENSE FOG ADVISORY AT THIS TIME. THE HRRR SHOWS LOCALLY REDUCED VSBY
TO AROUND ONE QUARTER OF A MILE THROUGH 15Z...THEN DISSIPATING. THIS
SEEMS TO MAKE SENSE WITH MOISTURE PROFILES ON BUFKIT SOUNDINGS. KCYS
RADAR LOOP SHOWS SHOWER ACTIVITY WINDING DOWN OVER FAR SOUTHEAST WY
INTO THE SOUTHERN NE PANHANDLE. THE NAM SHOWS WINDS SHIFTING TO THE
EAST/NORTHEAST AFTER 18Z AS A MID LEVEL DISTURBANCE MOVES OUT OF CO
AROUND THE SAME TIME. THIS FRAGMENTED WAVE WAS OBSERVED AT 12Z PER
RECENT WATER VAPOR IMAGERY. QPF SIGNALS INCREASE DRAMATICALLY DURING
THE AFTERNOON WITH THE RETURN OF EXCELLENT UPSLOPE...SO RAIN COULD
VERY WELL BECOME WIDESPREAD AGAIN LATER TODAY FROM THE HIGH COUNTRY
EASTWARD INTO CHEYENNE. PWAT VALUES REMAIN RESPECTABLE AROUND 0.5 TO
0.6 INCH...SO FELT COMFORTABLE BRINGING LIKELY POPS BACK INTO THE
PICTURE DURING THE LATE AFTN/EARLY EVE. THE NAM AND GFS BOTH SHOW A
RIBBON OF 500 J/KG SBCAPES ALONG THE I80 CORRIDOR IN OUR CWA...SO AT
LEAST A FEW LIGHTNING STRIKES ARE POSSIBLE. LIMITING FACTOR FOR ANY
AVAILABLE INSTABILITY WILL BE COOLER TEMPERATURES WITH UPSLOPE AND
RESULTING CLOUD COVER. THUNDERSTORMS COULD PRODUCE HAIL IN THIS TYPE
OF ENVIRONMENT IF THE MODELS VERIFY.
THINGS START TO GET INTERESTING ON FRIDAY AS A VIGOROUS LATE SEASON
WINTER STORM BEGINS TO TAKE SHAPE. WE ARE INDEED DEALING WITH A VERY
CHALLENGING FORECAST WITH RESPECT TO SNOW LEVELS AND RESULTING SNOW
AMOUNTS...AS WELL AS IMPACTS TO TRAVEL FOR MOTHERS DAY. GFS/NAM/ECM
ARE ALL IN EXCELLENT AGREEMENT WITH A VIGOROUS CLOSED LOW OVER THE
GREAT BASIN AT 12Z FRI. THIS FEATURE SLOWLY MEANDERS INTO THE FOUR
CORNERS REGION BY 06Z SAT WITH SURFACE CYCLOGENESIS RAMPING UP OVER
SOUTHEAST CO. ALL OF THE MODELS SHOW THIS SYSTEM LIFTING NORTHEAST
ON SAT NIGHT AND SUN WITH THE ASSOCIATED SUB-1000 MILLIBAR SURFACE
LOW SHIFTING INTO NORTHWEST KS. THIS TRACK ALLOWS MUCH COOLER AIR TO
SPILL INTO OUR HIGHER ELEVATION AREAS AS EARLY AS FRI NIGHT...WITH
H7 TEMPS FALLING TO -2C BY 12Z SAT. NAM WBZ HEIGHTS FALL TO AROUND
8000 FEET OR SO BY 09Z...AND FORECAST SOUNDINGS OVER THE SUMMIT ARE
FULLY SUPPORTIVE OF SNOW WHICH COULD BE HEAVY GIVEN A LAYER OF DEEP
SATURATION. A FEW PIECES OF ENERGY ROUNDING THE LOW WILL SUPPORT AN
INCREASE IN PCPN DURING THIS TIME...SO DO EXPECT THIS TO BE THE VERY
BEGINNING OF A POTENTIALLY SIGNIFICANT WINTER STORM EVENT. SLIGHTLY
NEGATIVE EPV VALUES SUGGEST ENOUGH INSTABILITY FOR A FEW CONVECTIVE
ELEMENTS AS WELL...FURTHER REINFORCING THE LIKELIHOOD OF SNOW.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 526 AM MDT THU MAY 7 2015
VERY CONCERNED THAT TRAVEL CONDITIONS MAY QUICKLY DETERIORATE BY SAT
MORNING...EVEN THOUGH THE MAIN SNOWFALL EVENT IS NOT EXPECTED UNTIL
LATER IN THE DAY ON SAT. THIS WOULD MAINLY BE OVER THE I80 SUMMIT...
BUT THIS AREA HAS BEEN A PROBLEM RECENTLY WITH VERY SIMILAR SYNOPTIC
SETUPS. WITH EARLY IMPACTS AND LIKELIHOOD OF MAJOR ACCUMULATIONS ON
SAT...WE DECIDED TO GO WITH A WINTER STORM WATCH FOR ALL OF OUR MTN
ZONES BEGINNING AT 06Z SAT. CONCERNING THE LATER EVOLUTION OF THIS
EVENT...NOTABLE COLD ADVECTION ALOFT APPEARS LIKELY ON SAT WITH H7
TEMPS FALLING TO BETWEEN -5 AND -10 DEG C ACROSS THE ENTIRE CWA BY
12Z SUN. THIS ULTIMATELY ALLOWS SNOW LEVELS TO FALL TO 5000 FEET OR
LOWER DURING THE COURSE OF THE EVENT. THE TRICKY PART WILL BE TIMING
WHEN THIS OCCURS FROM W TO E. ESPECIALLY CONCERNED ABOUT CHEYENNE AS
THE EUROPEAN SHOWS A DISTINCT COLD AIR DAMMING SIGNATURE DRAPED OVER
THE CO FRONT RANGE. THAT WAS OUR ACHILLES HEEL WITH THE LAST CLOSED
LOW WE DEALT WITH...AND IT KEPT WINDS NORTHERLY AT KCYS WITH COLDER
TEMPERATURES THAN MODELS PROGGED. THIS HAS BEEN THE ONLY MODEL TO
SHOW THIS SO FAR...BUT CAUTIOUSLY TRENDED LOWER ON TEMPS. THIS COULD
CAUSE SNOWFALL AMOUNTS TO BE SIGNIFICANTLY HIGHER AS THE HEAVIER
PCPN COULD VERY WELL BEGIN AS SNOW. WILL MAINTAIN A 6-10 INCH FCST
LOCALLY...BUT THIS MAY NEED TO BE REVISED. LATER SHIFTS WILL MOST
LIKELY NEED TO EXPAND THE WATCH EASTWARD INTO THE PLAINS. SHOULD
ALSO NOTE THAT GFS/SREF/NAM SOUNDINGS ALL SHOW A SUB-ZERO THERMAL
PROFILE AT LUSK ALL DAY ON SAT...SO COULD SEE SOME LOCALLY HIGHER
AMOUNTS IN THE HIGHER TERRAIN OUT THERE.
QPF SIGNALS FROM ALL MODELS ARE SCARY TO SAY THE LEAST. BUT ALAS...
THEY ARE BELIEVABLE WITH IMPRESSIVE MOISTURE (0.5 INCH PWATS FOR A
WINTER EVENT) COMBINED WITH EXCELLENT DYNAMIC SUPPORT BENEATH VERY
DIFLUENT FLOW AND A COUPLED UPPER JET. ALSO SEEING SOME INSTABILITY
IN THE MIX TOO WHICH WILL LIKELY LEAD TO MESOSCALE BANDING. NAM IS
STILL THE OUTLIER WITH THE HEAVIER PCPN DISPLACED WELL TO THE EAST
OF OUR CWA. GFS/ECMWF HAVE BEEN VERY CONSISTENT WITH WIDESPREAD 2-4
INCH LIQUID AMOUNTS...ESPECIALLY ALONG/EAST OF THE LARAMIE RANGE
WITH SIGNIFICANT UPSLOPE EXPECTED. THE NEW SREF IS TAGGING ALONG AS
WELL WITH HIGHER-END AMOUNTS. THAT SAID...CONFIDENCE IS VERY HIGH
THAT WE WILL SEE A SIGNIFICANT PRECIPITATION EVENT. WITH FORECAST
SOUNDINGS AS COLD AS THEY ARE...A FAIR AMOUNT OF THIS WILL PROBABLY
FALL AS SNOW. COULD SEE SEVERAL FEET IN THE MOUNTAINS. IT IS NOT
OUTSIDE OF THE REALM OF POSSIBILITY TO SEE A FOOT OR MORE FALL IN
CHEYENNE EITHER...BUT NEED TO SEE A FEW MORE MODEL RUNS TO BE SOLD
ON THAT SCENARIO. STAY TUNED AS THIS STORM APPEARS LIKELY TO GIVE US
QUITE A PUNCH. SNOW SHOULD FINALLY BEGIN TO DIMINISH BY SUN AFTN
AND/OR NIGHT AS THE LOW LIFTS INTO THE CENTRAL AND NORTHERN
PLAINS.
WITH THE LOW PRESSURE SYSTEM OPENING UP AND LIFTING OUT TO THE
NORTHEAST MONDAY...WE HAVE SOME LINGERING LIGHT SNOW SHOWERS IN
THE FORECAST FOR EARLY MONDAY MORNING...THEN WE SEE A CLEARING
AND WARMING TREND GOING THROUGH MIDWEEK. A RETURN OF DIURNAL
SHOWER/THUNDERSTORM CHANCES IS IN THE FORECAST BY LATE NEXT WEEK
AS WE SEE A NORTHWESTERLY FLOW ALOFT ON THE NORTHEAST SIDE OF A
4-CORNERS UPPER RIDGE. LOOKING JUST BEYOND THE 7 DAY FORECAST...
MODELS ARE SUGGESTING A MUCH WARMER AND DRIER WEEKEND FOR NEXT
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 526 AM MDT THU MAY 7 2015
IFR FLIGHT CATEGORY CEILINGS CONTINUE FOR RAWLINS...LARAMIE AND
CHEYENNE THROUGH MID MORNING BEFORE LIFTING TO MVFR...WITH MVFR TO
VFR CEILINGS AND VISIBILITIES EXPECTED EAST ACROSS SCOTTSBLUFF...
SIDNEY...ALLIANCE AND CHADRON THROUGH MID MORNING. LATEST HRRR AND
HIGHER RESOLUTION MODEL GUIDANCE SUGGESTING NEXT ROUND OF SHOWERS
WILL COME THIS AFTERNOON AS CONVECTION FIRES OVER THE MOUNTAINS
WEST OF CHEYENNE AND LARAMIE...MOVING EAST INTO SOUTHEAST WYOMING
AND THE WESTERN NEBRASKA PANHANDLE THIS AFTERNOON. FOR NOW WE WILL
CARRY A MENTION OF THUNDER IN THE VICINITY FOR ALL AIRPORTS EXCEPT
CHADRON THIS AFTERNOON AND EVENING IN THE REGION OF MARGINAL
INSTABILITY.
&&
.FIRE WEATHER...
ISSUED AT 526 AM MDT THU MAY 7 2015
THE COOL AND WET WEATHER PATTERN WILL CONTINUE THROUGH THE
WEEKEND...WITH FAIRLY HIGH CHANCES FOR MEASURABLE RAINFALL OR
SNOW. A STRONG STORM SYSTEM WILL IMPACT THE DISTRICTS THIS WEEKEND
WITH POTENTIALLY WIDESPREAD AND HEAVY PRECIPITATION AMOUNTS...AS
WELL AS GUSTY NORTHERLY WINDS. THIS SYSTEM WILL BE COLD
ENOUGH...WITH SNOW LEVELS DROPPING TO AROUND 5000 FEET. MINIMUM
RELATIVE HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL
THRESHOLDS THROUGH THE FORECAST PERIOD. A TREND TOWARD WARMER AND
DRIER CONDITIONS WILL COMMENCE BY TUESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY
AFTERNOON FOR WYZ103-112-114-116.
NE...NONE.
&&
$$
SHORT TERM...CLH/JG
LONG TERM...CLH
AVIATION...JG
FIRE WEATHER...JG
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
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...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
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 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 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
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 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 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.
&&
$$
17
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1011 AM EDT SAT MAY 9 2015
.DISCUSSION...
...MODERATE RIP CURRENT RISK...
TODAY-TONIGHT... ATLANTIC HIGH PRESSURE RIDGE HAS CONTINUED TO NUDGE
BACK NORTHWARD IN THE WAKE OF ANA. WITH A SEPARATE HIGH PRESSURE
CELL IN THE GULF...THE LOCAL AREA WAS IN A WEAK COL. THE RESULTING
LIGHT WIND FLOW PATTERN WILL ALLOW FOR QUICKER INLAND MOTION OF THE
EAST COAST SEA BREEZE.
A COLLISION OF THE WEST/EAST COAST BOUNDARIES WILL OCCUR OVER THE
INTERIOR DURING THE EARLY EVENING. THE MAIN QUESTION THOUGH IS THE
AMOUNT OF MOISTURE AVAILABLE FOR CONVECTION. MORNING CANAVERAL
SOUNDING AT FIRST GLANCE SHOWED SOME PROSPECT...WITH A PRECIPITABLE
WATER VALUE AROUND 1.5 INCHES. BUT WITH NORTHWARD LIFTING OF
SYNOPTIC FEATURES...SOUNDINGS AT TAMPA/MIAMI WILL ACTUALLY BECOME
MORE REPRESENTATIVE OF OUR AFTERNOON AIR MASS...AND THEY ARE DRIER.
WITH THE BOUNDARY COLLISION OCCURRING QUITE LATE AND IN A LIMITED
MOISTURE ENVIRONMENT...THE CURRENT FORECAST WHICH HAS SLIGHT SHOWER
CHANCES OVER THE INTERIOR...LOOKS OKAY. THE HRRR MODEL IS GENERALLY
SUPPORTIVE...SO WILL NOT MAKE ANY CHANGES.
&&
.AVIATION...MAINLY VFR. ANY INTERIOR SHOWERS THAT DEVELOP LATE IN
THE DAY WOULD BE BRIEF.
&&
.MARINE...
TODAY-TONIGHT...THE LIFTING OF ANA NORTHWARD IS ALLOWING THE
ATLANTIC HIGH PRESSURE RIDGE TO BUILD BACK TOWARDS THE WATERS. A
LIGHT SOUTH/SOUTHWEST GRADIENT WIND THIS MORNING WILL BECOME
DISTORTED BY THE SEA BREEZE CIRCULATION THIS AFTERNOON WITH MAINLY A
SOUTHEAST WIND SETTING UP ACROSS THE ATLANTIC WATERS WITH SPEEDS 10
KNOTS OR LESS...EXCEPT 10-13 KNOTS NEAR THE COAST WITH THE SEA BREEZE.
NORTHEAST SWELLS WILL KEEP SEAS SLIGHT ELEVATED DESPITE THE OVERALL
RATHER BENIGN GRADIENT WIND SPEEDS.
THEN AS THE RIDGE AXIS BUILDS INTO THE WATERS TONIGHT THE WIND FLOW
WILL BECOME SOUTH AT ABOUT 10-13 KNOTS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...LASCODY
IMPACT WX...WEITLICH
AREA FORECAST DISCUSSION
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 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 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
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...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 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
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 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 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 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 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 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...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
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 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 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 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 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