Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/30/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST FRI AUG 28 2015
.SYNOPSIS...LESS THUNDERSTORM COVERAGE THROUGH TONIGHT BEFORE
CHANCES INCREASE THIS WEEKEND. WE WILL KEEP ENOUGH MOISTURE FOR A
CHANCE OF THUNDERSTORMS FOR MOST OF NEXT WEEK. HOTTER THAN AVERAGE
TEMPERATURES FOR THE NEXT FEW DAYS BEFORE HIGH PRESSURE WEAKENS AND
TEMPERATURES SLOWLY FALL TO NEAR AVERAGE BY LATE NEXT WEEK.
&&
.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY DEPICTED SUNNY SKIES
ACROSS MUCH OF SE ARIZONA AT THIS TIME. HOWEVER...MOSTLY CLOUDY
SKIES WERE ONGOING ACROSS ABOUT THE SOUTHEAST HALF OF COCHISE
COUNTY...SE GRAHAM COUNTY AND PORTIONS OF GREENLEE COUNTY. DEWPOINTS
AT LOWER ELEVATIONS VALID 16Z RANGED FROM THE UPPER 50S-LOWER 60S.
THESE TEMPS WERE ABOUT 2-5 DEGS F HIGHER FROM TUCSON WWD VERSUS 24
HOURS AGO...BUT WERE NEARLY 2-5 DEGS F LOWER ACROSS ERN SECTIONS.
28/12Z KTWC SOUNDING TOTAL PRECIP WATER VALUE OF 1.41 INCHES WAS
DOWN ABOUT 0.10 INCH VERSUS 24 HOURS AGO. THE ENVIRONMENT WAS
MODESTLY UNSTABLE WITH LI/S RANGING FROM MINUS 2-4 DEPENDING UPON
LIFTING METHOD. THE 700-300 MB FLOW WAS QUITE LIGHT...WITH MAINLY
WLY/NWLY SPEEDS AROUND 5 KTS. 28/12Z UPPER AIR PLOTS CONTINUED TO
DEPICT AN EXPANSIVE RIDGE OVER MUCH OF THE WRN CONUS WITH A 595 DM
HIGH CENTERED OVER SW NEW MEXICO. LIGHT WLY/NWLY FLOW PREVAILED
ACROSS SE ARIZONA ABOVE 700 MB.
28/12Z UNIV OF AZ WRF-NAM AND SEVERAL HRRR SOLUTIONS WERE QUITE
SIMILAR WITH DEPICTING THE INITIAL DEVELOPMENT OF SHOWERS/TSTMS BY
NOON TO BE ACROSS THE WHITE MOUNTAINS...THE CHIRICAHUA MOUNTAINS IN
ERN COCHISE COUNTY AND THE PINALENO MOUNTAINS IN GRAHAM COUNTY. THE
BULK OF SHOWERS/TSTMS THEN APPEARS TO BE LIMITED TO MAINLY NEAR THE
MOUNTAINS EAST-TO-SOUTHEAST OF TUCSON INTO THIS EVENING. STORM
MOTIONS SHOULD BE VERY SLOW AND GENERALLY SEWD. HOWEVER...CANNOT
RULE OUT THE POSSIBILITY OF SHOWERS/TSTMS IN VALLEY LOCALES AS FAR
WEST AS TUCSON DUE TO DEVELOPMENT FROM CONVECTIVE OUTFLOWS.
THUS...THE OFFICIAL FORECAST WILL CONTINUE WITH ISOLATED TO
SCATTERED SHOWERS/TSTMS INTO THIS EVENING. THE BULK OF THIS ACTIVITY
SHOULD BE EAST OF TUCSON. A SLIGHT CHANCE OF SHOWERS/TSTMS CONTINUES
LATE TONIGHT INTO SAT MORNING EAST AND SOUTH OF TUCSON. HIGH TEMPS
THIS AFTERNOON WILL AVERAGE ABOUT 3-6 DEGS F ABOVE NORMAL.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 29/18Z.
EXPECT ISOLATED TO SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTH OF
KTUS INTO THIS EVENING. A FEW -TSRA/-SHRA MAY OCCUR LATE TONIGHT
INTO SATURDAY MORNING. MVFR CONDITIONS AND BRIEF WIND GUSTS OF 35-
45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD
DECKS WILL GENERALLY RANGE FROM 10-15K FT AGL AND SURFACE WIND WILL
MAINLY BE LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON
AND EVENING MAINLY EAST AND SOUTH OF TUCSON. SCATTERED THUNDERSTORMS
WILL RETURN TO MUCH OF SOUTHEAST ARIZONA SATURDAY...THEN SCATTERED
THUNDERSTORMS WILL PREVAIL MAINLY FROM TUCSON EAST AND SOUTH SUNDAY
THROUGH THURSDAY. BRIEF STRONG...GUSTY AND ERRATIC WINDS WILL
ACCOMPANY THE STRONGER THUNDERSTORMS. OTHERWISE...GENERALLY LIGHT
TERRAIN DRIVEN WINDS WILL OCCUR INTO NEXT WEEK.
&&
.PREV DISCUSSION /230 AM MST/...SATURDAY AFTERNOON DOESN`T LOOK THAT
IMPRESSIVE AS THE HIGH CONTINUES TO SLOWLY WOBBLE EASTWARD...BUT BY
LATE SATURDAY AFTERNOON AND EARLY SATURDAY EVENING...OUR MID LEVEL
FLOW WILL BE IN THE PROCESS OF PICKING UP A BIT EAST OF TUCSON. THIS
WILL FAVOR ORGANIZED EASTERLY THUNDERSTORM OUTFLOW DEVELOPMENT AND
SHOULD PUSH SOME STORMS DEEPER INTO OUR CWA (INCLUDING THE TUCSON
AREA) EARLY SATURDAY EVENING. HEIGHTS AND THICKNESSES CONTINUE TO
SUPPORT HOTTER THAN AVERAGE TEMPERATURES...BUT MUCH DEPENDS ON
TIMING AND LOCATIONS OF STORMS.
EVEN AS THE RIDGE DEEPENS THROUGH NORTHERN TIER STATES IN OUR REGION
SUNDAY AND MONDAY...WE SHOULD MAINTAIN FAVORABLE THUNDERSTORM
CONDITIONS THROUGH SOUTHEAST ARIZONA AS OUR WEATHER CONTINUES TO BE
DOMINATED BY FEATURES IN SONORA.
THERE`S ONLY SO LONG WE CAN MAINTAIN A WESTERLY COMPONENT TO OUR
FLOW HOWEVER...SO A DRYING TREND WILL KICK IN SOONER OR LATER IF THE
REGION KEEPS THE MEAN TROUGH POSITION THROUGH THE COMING WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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FRANCIS
PREVIOUS DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 PM MST THU AUG 27 2015
.SYNOPSIS...EXPECT DECREASED THUNDERSTORM ACTIVITY FRIDAY THEN
SCATTERED THUNDERSTORMS WILL RETURN ESPECIALLY FROM TUCSON EAST AND
SOUTH SATURDAY AND CONTINUE INTO NEXT WEEK. DAYTIME TEMPERATURES
WILL REMAIN ABOVE AVERAGE INTO EARLY NEXT WEEK...THEN HIGH
TEMPERATURES WILL TREND CLOSER TO NORMAL BY LATE NEXT WEEK.
&&
.DISCUSSION...VERY INTERESTING EVENING AS MOST OF THE ACTIVITY HAS
BEEN DRIVEN BY THUNDERSTORM OUTFLOW INTERACTIONS. ONE OF THE
OUTFLOWS THAT STARTED IN EASTERN PINAL COUNTY EARLIER THIS
EVENING HAS PUSHED S INTO NRN MEXICO. THERE WERE A FEW STRONG STORMS
EARLY IN THE EVENING ESPECIALLY N OF ARIVACA AND ON SE SIDE OF
TUCSON METRO AREA. SOUTH OF THE BORDER ACROSS NORTHERN SONORA THERE
WAS AN MCS. NORTH BOUND OUTFLOWS FROM THIS SYSTEM WILL LIKELY
INTERACT WITH SOUTH OF OUTFLOWS THAT PUSHED ACROSS THE INTERNATIONAL
BORDER FOR THE POSSIBILITY OF NEW THUNDERSTORM DEVELOPMENT SOUTH OF
THE BORDER. THESE STORMS CAN THEN SEND OUTFLOWS NORTH INTO COCHISE
COUNTY FOR NEW STORM DEVELOPMENT OVERNIGHT. LATEST HRRR RUN HINTING
AT THIS. WILL RUN. ON THE EVENING UPDATE WILL INCREASE POPS
OVERNIGHT ALONG THE INTERNATIONAL BORDER. CHECK PREVIOUS DISCUSSION
BELOW FOR THE REMAINDER OF THE FORECAST.
&&
.AVIATION...VALID THRU 29/00Z.
ISOLD-SCTD -TSRA/-SHRA...MAINLY S AND E OF KTUS THRU 28/12Z.
ISOLD TO PERHAPS SCTD -TSRA/-SHRA WILL THEN PREVAIL MAINLY E OF
KTUS FRI AFTN. MVFR CONDS AND BRIEF WIND GUSTS OF 35-45 KTS WILL
OCCUR WITH THE STRONGER T-STORMS. OTHERWISE...CLOUD DECKS WILL
GENERALLY RANGE FROM 10-15K FT AGL AND SURFACE WIND WILL MAINLY BE
LESS THAN 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORMS WILL BE LIMITED TO MAINLY NEAR THE
MOUNTAINS EAST OF TUCSON FRIDAY. SCATTERED THUNDERSTORMS WILL RETURN
TO MUCH OF SOUTHEAST ARIZONA SATURDAY...THEN SCATTERED THUNDERSTORMS
WILL PREVAIL MAINLY FROM TUCSON EAST AND SOUTH SUNDAY THROUGH
THURSDAY. BRIEF STRONG...GUSTY AND ERRATIC WINDS WILL ACCOMPANY THE
STRONGER THUNDERSTORMS. OTHERWISE...GENERALLY LIGHT TERRAIN DRIVEN
WINDS WILL OCCUR INTO NEXT WEEK.
&&
.PREV DISCUSSION...MARKEDLY LESS COVERAGE OF SHOWERS/TSTMS IS ON TAP
FRI AFTERNOON AS HIGH PRESSURE ALOFT BECOMES CENTERED OVER THE AREA.
SOME MESOSCALE MODELS SUGGEST THAT ANY THUNDERSTORMS THAT OCCUR FRI
AFTERNOON/EVENING WILL BE CONFINED ONLY NEAR MOUNTAINS EAST OF
TUCSON. FOR NOW...HAVE OPTED FOR ISOLATED TO SCATTERED SHOWERS/TSTMS
MAINLY FROM TUCSON EWD TO THE NEW MEXICO BORDER FRI AFTN/EVENING.
THE UPPER HIGH IS PROGGED TO REMAIN QUASI-STATIONARY OVER THE AREA
SAT. HOWEVER...HAVE ADJUSTED POPS UPWARD FAIRLY SUBSTANTIALLY ACROSS
MUCH OF THE AREA AS MODELS SUGGEST THAT A GENERALLY NELY STEERING
FLOW REGIME MAY DEVELOP. THUS...SCATTERED SHOWERS/TSTMS ARE EXPECTED
TO OCCUR ACROSS MUCH OF THIS FORECAST AREA SAT AFTERNOON/EVENING.
THEREAFTER...THE MID-LEVEL STEERING FLOW IS PROGGED TO BECOME SWLY
SUN AND CONTINUE INTO THURSDAY AS UPPER RIDGE AXIS WILL BE OVER THE
CENTRAL/SRN CONUS PLAINS...AND AN UPPER TROUGH BECOMES ESTABLISHED
YET AGAIN ADJACENT THE WEST COAST. THIS PATTERN SHOULD YIELD
ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS SUN-
THUR. ABOVE NORMAL DAYTIME TEMPERATURES WILL ALSO PREVAIL FRI THRU
MON OR TUE...THEN HIGH TEMPS WILL TREND CLOSE TO SEASONAL NORMALS BY
NEXT THUR.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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!--NOT SENT--!
AREA FORECAST DISCUSSION
NWS PUEBLO CO
256 PM MDT FRI AUG 28 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 242 PM MDT FRI AUG 28 2015
TODAY AN UPR RIDGE IS OVR UT AND WRN CO...WITH NW FLOW ALOFT OVR ERN
CO AND A WEAK UPR DISTURBANCE MOVING THRU THE NW FLOW OVR ERN CO AND
WRN KS. THE NAM AND HRRR SHOW ISOLD TO SCT CONVECTION OVR THE HYR
TRRN AND PORTIONS OF THE I-25 CORRIDOR THRU THIS EVENING...BUT THE
HRRR ALSO SHOWS THE POTENTIAL FOR A FEW SHOWERS/TSTMS OVR THE SERN
PLAINS AS WELL. HAVE ALREADY SEEN A FEW ECHOES DEVELOP OVR BACA AND
ERN LAS ANIMAS COUNTIES...SO WL KEEP SOME ISOLD POPS FOR THESE
LOCATIONS THIS EVENING...BUT WL KEEP SILENT POPS OVR THE REST OF THE
SERN PLAINS. THE DISTURBANCE WILL EXIT THE REGION IN THE
EVENING...AND PCPN CHANCES ACRS THE AREA ARE GENERALLY EXPECTED TO
END BY MIDNIGHT.
ON SATURDAY THE UPR RIDGE MOVES OVR THE AREA. WITH LIMITED
MOISTURE...ONLY ISOLD TO SCT PCPN CHANCES ARE EXPECTED OVR THE NR
THE HYR TRRN. HIGH TEMPS SATURDAY SHOULD BE AROUND TO SLIGHTLY
ABOVE AVERAGE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 242 PM MDT FRI AUG 28 2015
MODELS IN DECENT AGREEMENT THROUGH THE EXTENDED PERIOD WITH LOW
ENSEMBLE SPREADS. THE UPPER PATTERN WILL REMAIN NEARLY STATIONARY
WITH RIDGING NORTHWARD OUT OF THE DESERT SOUTHWEST...STRETCHING
NORTHEAST INTO THE NORTHERN PLAINS...AND AN UPPER TROUGH SITS
ALONG THE WEST COAST. EXPECT PERSISTENT SOUTHWESTERLY FLOW ALONG
WITH MONSOONAL MOISTURE TO CONTINUE ACROSS COLORADO THROUGH THE
EXTENDED PERIOD. SHOWER AND THUNDERSTORM CHANCES WILL BE HIGHLY
DEPENDENT UPON EMBEDDED ENERGY IN THE SOUTHWEST FLOW. CURRENT
MODEL ANALYSIS BRINGS NEAR DAILY DISTURBANCES ACROSS THE AREA
SATURDAY NIGHT THROUGH TUESDAY. SHOWERS AND THUNDERSTORMS ARE
FORECAST TO DEVELOP OVER THE MOUNTAINS DURING THE AFTERNOON
HOURS...AND SPREAD EAST INTO THE I-25 CORRIDOR DURING THE EVENING
BEFORE DISSIPATING OVERNIGHT. THE GFS IS DRIER ON WEDNESDAY AND
THURSDAY...AND THE ECMWF IS COMPLETELY DRY THESE DAYS. FOR NOW
HAVE LOW POPS IN THE FORECAST FOR THE MOUNTAINS WEDNESDAY AND
THURSDAY. A STRONGER DISTURBANCE IS LIKELY TO MOVE NORTH OUT OF
THE DESERT SOUTHWEST ON FRIDAY...WITH AN UPTICK IN SHOWER AND
THUNDERSTORM ACTIVITY. SHOWERS AND THUNDERSTORMS WILL BE CAPABLE
OF PRODUCING LOCALLY HEAVY RAINFALL...AND FLASH FLOODING WILL
CONTINUE TO BE A THREAT...ESPECIALLY ON AREA BURN SCARS. TEMPERATURES
WILL REMAIN WARM THROUGH THE EXTENDED PERIOD WITH 80S AND 90S
ACROSS MUCH OF THE AREA FOR AFTERNOON HIGHS. MOZLEY
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 242 PM MDT FRI AUG 28 2015
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES TONIGHT THROUGH
SATURDAY AFTERNOON. THERE IS A SLIGHT CHANCE FOR ISOLD
SHOWERS/TSTMS IN THE VCNTY OF THE TAF SITES THIS EVENING.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MOZLEY
AVIATION...28
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
850 PM EDT SAT AUG 29 2015
...HEAVY RAIN THREAT THROUGH MONDAY...
CURRENT-REST OF TONIGHT...FAST MOVING BANDS OF SHOWERS AND ISOLATED
STORMS MOVING SOUTHEAST TO NORTHWEST AT 25 TO 30 MPH OR MORE OVER
THE ATLANTIC. THE FIRST WAVE OF SHOWERS AND STORMS PRODUCED MEASURED
GUSTS OF 45 TO 50 MPH AT THE SOUTHERN BREVARD COASTAL AREAS. THE
MELBOURNE DOPPLER RADAR WAS DETECTING VELOCITIES TO 40 TO 45 KNOTS
BETWEEN A 1000 AND 2000 FEET OF THE SURFACE. THE WINDS DIMINISHED A
LITTLE AS THEY MOVED INLAND BUT WERE STILL GUSTING OVER 30 MPH JUST
WEST OF THE INDIAN RIVER LAGOON IN BREVARD COUNTY. RADARS STILL
DETECTING MORE BANDS OF SHOWERS AND STORMS OFF THE COAST FROM VERO
BEACH SOUTH MOVING TOWARD THE SHORE AT AROUND 25 MPH. THE HRRR MODEL
IS SUGGESTING SCATTERED TO NUMEROUS GUSTY SHOWERS AND STORMS MOVING
OVER THE COASTAL WATERS...COMING ASHORE AND REACHING WELL INLAND
BEFORE DIMINISHING THE WHOLE NIGHT.
PREVIOUS ZONE DISCUSSION
TONIGHT...SURFACE-850 MB SOUTHEAST WINDS WILL INCREASE TO 20-25
KNOTS AS THE REMNANT LOW PRESSURE TROUGH FROM ERIKA MOVES INTO THE
FLORIDA STRAITS. THIS WILL FAVOR CONVERGENCE LINES OFF THE BAHAMAS
AND SOME COASTAL CONVERGENCE. THEREFORE ONCE LINGERING DEBRIS
RAINFALL AND SCATTERED STORMS END THIS EVENING...THERE WILL BE A
GOOD CHANCE FOR SHOWERS AND STORMS ALONG THE COAST OVERNIGHT. THE
LATEST GFS SHOWS THE HIGHEST RAIN AMOUNTS ALONG THE TREASURE
COAST...WITH POPS 50-60 PERCENT AND WILL FOLLOW CLOSE TO MOS VALUES.
SUN...HIGH PRECIPITABLE WATER NEAR 2.25 INCHES WILL ENCOMPASS THE
AREA AS THE LOW PRESSURE TROUGH PUSHES INTO THE SOUTHEAST
GULF. INCREASED LOW LEVEL CONVERGENCE DUE TO THE TROUGH...COMBINED
WITH UPPER LEVEL DIVERGENCE DUE TO MID/UPPER LEVEL TROUGH IN THE
GULF....WILL PRODUCE VERY HIGH RAIN CHANCES AND A THREAT FOR HEAVY
RAIN. THIS IS EVIDENCED BY THE 12Z GFS POPS 80-100 PERCENT AND 12
HOUR QPF VALUES 2 INCHES OR GREATER. THINK THAT THE HEAVY RAIN
CHANCES WILL BE NEAR THE COAST IN THE MORNING THEN TRANSITION TO
THE INTERIOR IN THE AFTERNOON AS MODEST HEATING OCCURS THROUGH
LATE MORNING.
SUN NIGHT...WITH THE HIGH MOISTURE AND STILL BREEZY LOW LEVEL
WINDS...THE CHANCE FOR SHOWERS/STORMS WITH HEAVY RAIN WILL
CONTINUE QUITE HIGH AND HAVE KEPT PREVIOUS POPS WHICH WERE 60
PERCENT.
MON...THE GFS SHOWS SURFACE LOW PRESSURE TROUGH PUSHING FARTHER
OUT INTO THE GULF AROUND 86W. WHILE THE LOW LEVEL WINDS/CONVERGENCE
WILL WEAKEN UNDER THIS SCENARIO...AND UPPER LEVEL DIVERGENCE ALSO
DECREASES...HIGH PRECIPITABLE WATER 2.25 INCHES OR GREATER IS
FORECAST TO CONTINUE. THEREFORE LIKELY POPS INDICATED BY THE MOS
AND INCLUDED IN THE PREVIOUS FORECAST LOOK GOOD. THE THREAT OF
FOR HEAVY RAIN WILL CONTINUE. GFS MODEL AMOUNTS FOR THE SUN-MON
PERIOD ARE 1-3 INCHES AREAWIDE...WHICH LOOKS REASONABLE.
HOWEVER...WITH PRECIPITABLE WATER VALUES 2.25 INCHES THROUGH THE
PERIOD...LOCALLY HIGHER AMOUNTS 3-5 INCHES ARE CERTAINLY POSSIBLE.
TUE-FRI...REMNANT SURFACE TROUGH FROM ERIKA IS FORECAST TO MOVE
SLOWLY IN THE NORTHEAST GULF OF MEXICO OR GRADUALLY WASH OUT.
ATLANTIC SURFACE RIDGE SHOULD EXTEND NORTH OF THE REGION AND
CONTINUE A SOUTHEASTERLY WIND FLOW...WITH MORE TYPICAL LIGHTER
SPEEDS THOUGH. MOISTURE LOOKS ELEVATED WITH LAPSE RATES RATHER
AVERAGE. EXPECT A RETURN TO SCATTERED AFTERNOON/EVENING
SHOWERS/STORMS.
&&
.AVIATION... FAST MOVING IFR SHOWERS WITH OCCASIONAL GUSTS OF 30 TO
40 KNOTS THE REST OF THE NIGHT KDED-KSFB-KISM-KOBE EAST. SPEED OF
THE SHOWERS AND ISOLATED STORMS WAY TOO FAST FOR TEMPO GROUPS OVER
AN HOURS.
PREVIOUS AVIATION DISCUSSION...
SCT TSRA FROM KMCO-KDED WILL MOVE WESTWARD INTO LATE AFTERNOON WITH
ADDITIONAL SHRA/TSRA EXPECTED TO DEVELOP FROM KLEE-KISM INTO EARLY
EVENING. HRRR INDICATES SOME CONVECTION MAY PUSH BACK TO KSFB-KMCO
CORRIDOR INTO LATE EVENING WITH MID LVL SW FLOW. SCATTERED ATLC
SHOWERS WILL INCREASE IN COVERAGE AND MOVE ONSHORE FROM KMLB-KSUA
OVERNIGHT WITH TEMPO SHRA EXPECTED FOR THE LATE NIGHT HOURS
PROGRESSING INTO THE INTERIOR BY LATE MORNING ON SUNDAY. MVFR CIGS
AND IFR VSBYS PSBL WITH +SHRA/+TSRA IN CONVECTION.
&&
.MARINE... CURRENT-OVERNIGHT...NOAA/SCRIPPS BUOYS RECORDING EAST
SOUTHEAST WINDS AROUND 15 KNOTS AND 2 TO 3 FOOT SEAS JUST OFF THE
BEACH AND TO 5 FEET WELL OFFSHORE. GUIDANCE INDICATING WINDS 15 TO
20 KNOTS CAPE CANAVERAL SOUTH AND 10 TO 15 KNOTS TO THE NORTH. SMALL
CRAFT OPERATORS SHOULD EXERCISE CAUTION FOR WINDS CAPE CANAVERAL
SOUTH THE REST OF THE NIGHT. BOATERS AND SHIP OPERATORS WILL NEED TO
KEEP AN EYE TO THE SOUTHEAST FOR FAST MOVING STORMS CAPABLE OF
GUSTS OVER 30 KNOTS.
PREVIOUS MARINE DISCUSSION
TONIGHT...PRESSURE GRADIENT WILL GRADUALLY TIGHTEN AS LOW PRESSURE
TROUGH FROM REMNANTS OF ERIKA LIFTS INTO THE FLORIDA STRAITS.
EAST/SOUTHEAST WINDS WILL INCREASE ENOUGH TONIGHT FOR EXERCISE
CAUTION CONDITIONS IN THE SOUTH. ELSEWHERE THERE WILL BE MORE WIND
CHOP SO CONDITIONS STARTING OUT SUNDAY LOOK POOR FOR SMALL CRAFT
OVER ALL OF THE WATERS.
SUN-MON...THE WEATHER CONDITIONS LOOK POOR WITH SCATTERED TO
NUMEROUS SHOWERS AND STORMS WITH GUSTY WINDS TO 30 KNOTS. OUTSIDE
THE CONVECTION...GRADIENT WILL SUPPORT EXERCISE CAUTION FROM ABOUT
THE CAPE SOUTH ON SUNDAY AND POSSIBLY INTO SUNDAY EVENING.
SOUTHEAST WINDS WILL DIMINISH TO 10-15 KNOTS LATE SUNDAY NIGHT AND
INTO MONDAY.
TUE-WED...HIGH PRESSURE RIDGE ALONG THE EASTERN SEABOARD WILL
CONTINUE TO PRODUCE A SOUTHEAST WIND FLOW BUT SPEEDS LOOK CLOSER
TO 10 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 77 86 76 86 / 30 70 60 70
MCO 76 89 75 89 / 30 70 50 70
MLB 78 87 77 88 / 30 80 60 70
VRB 78 88 77 88 / 40 80 60 70
LEE 76 92 75 89 / 30 70 40 60
SFB 76 88 75 89 / 30 70 50 70
ORL 76 88 75 88 / 30 70 50 70
FPR 78 89 77 89 / 40 80 60 70
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH MONDAY EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-INLAND VOLUSIA COUNTY-MARTIN-NORTHERN BREVARD
COUNTY-NORTHERN LAKE COUNTY-OKEECHOBEE-ORANGE-OSCEOLA-
SEMINOLE-SOUTHERN BREVARD COUNTY-SOUTHERN LAKE COUNTY-ST.
LUCIE.
AM...NONE.
&&
$$
PENDERGRAST/ULRICH/WIMMER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1000 AM EDT FRI AUG 28 2015
.Near Term [Through Today]...
The 12Z TAE sounding showed quite an unstable environment with
mid-level lapse rates of about 7 C/km and MUCAPE of over 2200
J/kg. This matches up well with the RUC forecast, which shows
SBCAPE increasing to 2000-2500 J/kg over the next few hours. This
morning`s sounding showed a PWAT of only 1.61", which is fairly
dry for us this time of year, but 10-15 knot 1000-700 mb flow will
help increase low level moisture through the day and is a
favorable seabreeze pattern for widespread coverage of
thunderstorms across the area. Local satellite and radar imagery
show storms already active across our eastern coastal waters and
making further inland progression than originally forecast this
morning, so bumped up PoPs a bit through the remainder of the
daylight hours. Lingering dry air in the mid-levels and moderate
instability could combine to produce an environment somewhat
favorable for downbursts. Isolated strong to severe storms will be
possible with gusty winds the main threat.
&&
.Prev Discussion [653 AM EDT]...
.Short Term [Tonight Through Sunday]...
An elongated area of +PV stretches from the Northeast, through the
central Gulf of Mexico this morning. By tonight this area will
split into two anomalies: a more progressive wave moving off the
Northeast coast and what will be a quasi-stationary wave over the
north-central Gulf. It won`t be until Saturday night through
Sunday that this wave lifts through the Southeast. At the surface,
ridging will prevail across much of the eastern half of the
country. Locally, the ridge will be quite disturbed due to the
upper wave. Steering flow will generally have a south or
southeasterly component yielding a rather wet seabreeze regime
across the entire Tri-State area. Like the ridge, the seabreeze
will be far from ideal and enhanced by the upper level anomaly.
Thus, PoPs will be higher than normal through the weekend
(50-70%). High PoPs and plentiful cloud cover will keep afternoon
highs anywhere from the mid 80s to around 90 degrees. Overnight
lows will be in the middle 70s and not as pleasant as recent
nights as moisture surges back into the region.
.Long Term [Sunday Night Through Friday]...
The main feature in the extended range forecast will be what is
now Tropical Storm Erika. The eventual track will have a lot to do
with how Erika holds together as it moves across Hispaniola today.
The current track from NHC takes Erika south of the Bahamas before
curving it north along the immediate east coast of Florida. A
concerning trend in the dynamical models is a westward shift in
the track. Both the 00z GFS and ECMWF bring Erika into the eastern
Gulf, but diverge greatly with respect to timing. There has been a
lot of back and forth between the dynamical models and a great
deal of uncertainty still exists. But, the potential for at least
some sort of impacts locally from Erika appears to be increasing
over the past 24 hours. A track off the east coast of Florida will
bring minimal rain impacts to the Tri-State region, while a track
over the Peninsula will likely bring a great deal of rain over the
Suwannee Valley, and a track into the eastern Gulf would mean the
potential for both heavy rain and wind impacts area-wide. Due to
the uncertainty in this forecast and the latest trends, close
attention should be given to the forecast over the next couple of
days.
.Aviation...
[Through 12Z Saturday] VFR conditions are expected this morning,
with scattered to numerous showers and storms likely between 18Z
and 03Z. These showers and storms may affect any of the terminals
during that timeframe. This was handled in the TAFs with VCTS at
all of the terminals. Confidence was high enough in a particular
window where storms are more likely at VLD (21-01Z) to include a
TEMPO group with some gusty winds and IFR visibility. Similar
conditions (gusty winds and IFR visibility) will be possible in
any storms today, but confidence was not high enough in timing at
any of the other terminals to include additional TEMPO groups.
.Marine...
Light winds and low seas will prevail through the weekend. After
that, it will depend on Erika`s track. No matter the track, at
least a slight increase in winds and possibly seas should be
expected starting next week.
.Fire Weather...
An increase in low-level moisture will keep RH levels elevated and
allow rain chances to increase from today into the weekend.
.Hydrology...
With a transition to a wetter pattern beginning today, expect
average rainfall amounts on the order of 1-1.5" over the next
three days. This will have little impact on area rivers. Next
week, the potential for some very heavy rain exists depending on
Erika`s track. At this time, models suggest the possibility for
5-7" over a 48 hour period with Erika. Should the track shift
west, these amounts could spread into the southeast Big Bend and
south-central Georgia. Interests along the Suwannee River are
urged to pay close attention to rainfall forecasts over the next
few days.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 91 75 86 73 90 / 50 40 60 30 50
Panama City 87 77 85 75 88 / 40 50 60 30 30
Dothan 91 73 85 70 89 / 50 40 60 30 30
Albany 91 73 86 71 89 / 50 40 60 40 40
Valdosta 91 74 87 73 90 / 50 40 60 30 50
Cross City 90 75 88 74 90 / 40 40 60 30 50
Apalachicola 89 77 85 76 87 / 50 60 60 40 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...MOORE
SHORT TERM...HARRIGAN
LONG TERM...HARRIGAN
AVIATION...LAMERS
MARINE...HARRIGAN
FIRE WEATHER...LAMERS
HYDROLOGY...HARRIGAN
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
901 PM EDT SAT AUG 29 2015
.UPDATE...
UPDATED FORECAST IN GOOD SHAPE. SHRA STILL ACTIVE IN NW
CORNER...MIDDLE GA EAST OF KCSG AND FAR SE. LITTLE IF ANY
CONVECTION SEEN THIS AFTERNOON AND NONE EXPECTED OVERNIGHT.
ANOTHER ROUND OF SHRA LIKELY EARLY SUN MORNING BASED ON HRRR AND
SOME HIRES MODELS. NOT A SLAM DUNK BUT ENOUGH TO KEEP POPS FAIRLY
HIGH FOR THAT TIME OF NIGHT.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 333 PM EDT SAT AUG 29 2015/
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
THE SHORT TERM MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD
KEEPING A MOIST AIRMASS IN PLACE. THE UPPER LEVEL LOW OVER THE
NORTHERN GULF WILL CONTINUE TO LIFT ACROSS SOUTH ALABAMA INTO
NORTHWEST GA BY SUNDAY EVENING AND NORTH OF THE FORECAST AREA
SUNDAY NIGHT. WEAK IMPULSES WILL CONTINUE TO LIFT ACROSS THE
FORECAST AREA AHEAD OF THE LOW. HIGH PRESSURE OVER THE CAROLINAS
WILL KEEP EASTERLY FLOW AT THE SURFACE. THIS WILL REINFORCE SOME
LOWER CLOUDS BY MORNING ACROSS THE AREA WITH MID LEVEL CEILINGS
EXPECTED ACROSS THE REGION. ALTHOUGH INSTABILITY WILL BE
MINIMAL...ISOLATED THUNDER WILL BE POSSIBLE AS THE IMPULSES LIFT
NORTH THROUGH TOMORROW. THE AREAS OF SHOWERS WILL CONTINUE
OVERNIGHT...WITH BEST CHANCES OVER WEST GA...BUT DO EXPECT SOME
LULLS. GUIDANCE TEMPERATURES ARE IN LINE AND HAVE TAKEN A BLEND OF
MAV/MET.
ATWELL
LONG TERM /MONDAY THROUGH SATURDAY/...
NO MAJOR CHANGES TO THE ONGOING LONG TERM FORECAST.
THE REMNANTS OF ERIKA STILL EXPECTED TO IMPACT THE CWFA NEXT WEEK.
FOR NOW...THE SYSTEM WILL REMAIN A LOW PRESSURE TROUGH AS IT COMES
ONSHORE ACROSS THE FLORIDA PANHANDLE EARLY NEXT WEEK.
THE PERSISTENT SOUTHERLY FLOW ALOFT WILL BRING ABUNDANT MOISTURE
NORTHWARD FROM THE GULF OF MEXICO FOR MUCH OF NEXT WEEK...SO CHANCE
POPS STILL NEEDED EVERY DAY. IN ADDITION...AN UPPER TROUGH ACROSS
THE EASTERN HALF OF THE COUNTRY WILL HELP KEEP TEMPERATURES MOSTLY
IN THE 80S THROUGH THE PERIOD.
WIND SHEAR IN THE GULF IS A LITTLE WEAKER...SO SOME REGENERATION OF
ERIKA IS POSSIBLE.
NLISTEMAA
&&
.AVIATION...
00Z UPDATE...
PRIMARY CONCERN IS CHC FOR IFR CIGS SUN MORNING AND CHC FOR TSRA
SUN AFTERNOON. DECENT CHC FOR ANOTHER ROUND OF MORNING RAIN MOVING
IN FROM THE SOUTH AFTER 08Z AT ATL METRO AIRPORTS. COULD SEE CIGS
DROP TO IFR AND LINGER INTO THE LATE MORNING...THOUGH CLIMATOLOGY
DOES NOT OFTEN SUPPORT THIS IN LATE AUGUST. STILL APPEARS
POSSIBLE. AFTER RAIN MOVES OUT...SHOULD SEE SOME CLEARING AND SCT
TSRA. HAVE ADDED PROB30 FOR TSRA 19-22Z. AFTER 00Z SHOULD BE
CLEARING QUICKLY. EAST COMPONENT WINDS 5-10KTS EXPECTED THRU FCST.
//ATL CONFIDENCE...00Z UPDATE...
LOW CONFIDENCE ON SHRA/IFR CIGS SUN MORNING.
MEDIUM-HIGH CONFIDENCE ON MVFR CIGS SUN MORNING AND TSRA
LIKELIHOOD SUN AFTERNOON.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 68 81 67 85 / 40 50 20 30
ATLANTA 69 82 69 85 / 50 50 20 20
BLAIRSVILLE 63 76 62 82 / 40 40 20 30
CARTERSVILLE 67 81 66 87 / 40 40 20 20
COLUMBUS 70 87 69 89 / 40 50 20 20
GAINESVILLE 67 78 67 83 / 40 50 20 30
MACON 69 84 69 87 / 50 50 30 30
ROME 68 82 66 87 / 40 40 20 20
PEACHTREE CITY 67 83 68 86 / 50 50 20 20
VIDALIA 71 86 70 85 / 60 50 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....39
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
616 PM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH
TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER
THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC
MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN
PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS
SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN
FLORIDA SUNDAY NIGHT. REFER TO THE LATEST ADVISORY ON ERIKA
ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH SATURDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE EVENING
AND OVERNIGHT HOURS. A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED
OFF THE SC COAST. AS A RESULT...A NORTHEASTERLY/EASTERLY FLOW WILL
PERSIST OVER THE FORECAST AREA. LATEST RADAR LOOP SHOWING A FEW
SHOWERS MAINLY ALONG THE COAST AND ACROSS CNTRL/SRN GA. SLIGHT
CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE
FOR THE EARLY EVENING HOURS.
OVERNIGHT...MAINLY DRY CONDITIONS UNDER PARTLY CLOUDY SKIES.
OVERNIGHT LOWS RANGING FROM THE MIDDLE 60S NORTH TO AROUND 70
SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED
TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST
SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT
NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE
NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND
MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH
PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND
CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE
S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING
SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK
SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH
OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER
OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA
BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN
WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC
MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION
OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE
IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING
FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH.
GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO
STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS
INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF
AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED
TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE
STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND
SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE
AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT
THUNDERSTORMS SATURDAY AFTERNOON BUT EXPECT SCATTERED COVERAGE
WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT
THIS TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
607 PM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST THROUGH
TONIGHT...WITH DRY SURFACE HIGH PRESSURE REMAINING ANCHORED OVER
THE WESTERN AND CENTRAL CAROLINAS. INCREASING ATMOSPHERIC
MOISTURE WILL DRIFT SLOWLY NORTH INTO MAINLY SOUTHERN AND WESTERN
PORTIONS OF OUR REGION LATE SATURDAY...AND INTO REMAINING AREAS
SUNDAY. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH SOUTHERN
FLORIDA SUNDAY. REFER TO THE LATEST ADVISORY ON ERIKA ISSUED BY
THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH SATURDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE SOUTHEAST FOR THE REST OF
THE AFTERNOON THROUGH TONIGHT WITH A WEAK FRONTAL BOUNDARY STALLED
OFF THE SC COAST. AS A RESULT...A NORTHEASTERLY/EASTERLY FLOW WILL
PERSIST OVER THE FORECAST AREA. LATEST RADAR LOOP SHOWING A FEW
SHOWERS MAINLY ALONG THE COAST AND OVER THE CSRA. LATEST HRRR
SHOWING ISOLATED COVERAGE AT BEST THIS AFTERNOON. SLIGHT CHANCE
POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS APPROPRIATE. HIGH
TEMPERATURES ARE FORECAST NEAR NORMAL...IN THE UPPER 80S.
FOR TONIGHT...MAINLY DRY CONDITIONS UNDER PARTLY CLOUDY SKIES.
OVERNIGHT LOWS RANGING FROM THE MIDDLE 60S NORTH TO AROUND 70 SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
MEAN UPPER TROUGH TO OUR WEST WITH UPPER RIDGE REMAINING CENTERED
TO OUR E AND SE. SHORTWAVE ENERGY MOVING EAST INTO THE MIDWEST
SAT/SUN WILL ALLOW UPPER ENERGY AND MOISTURE TO SLOWLY SHIFT
NORTH FROM THE GULF INTO OUR REGION. WITH THE EXCEPTION OF THE
NAM...MODELS CONTINUE TO TREND SLOWER WITH MOISTURE RETURN...AND
MAINLY RELEGATE IT TO THE S AND W FA SATURDAY...AS SURFACE HIGH
PRESSURE AND DRIER AIR REMAINS ENTRENCHED OVER THE WESTERN AND
CENTRAL CAROLINAS. THINK SLIGHT CHANCE POPS BY AFTERNOON FOR THE
S/W FA LOOK OK SATURDAY. MOISTURE EXPECTED TO CONTINUE TRENDING
SLOWLY NORTH SATURDAY NIGHT INTO SUNDAY...WITH INDICATIONS OF WEAK
SURFACE HIGH PRESSURE AND DRIER AIR STILL TRYING TO HANG TOUGH
OVER THE WESTERN CAROLINAS. MODELS INDICATE A POP GRADIENT OVER
OUR FA SUNDAY WITH LOWER POPS NORTH/HIGHER POPS SOUTH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
UPPER TROUGH TO REMAIN TO OUR WEST WITH UPPER RIDGE TO OUR EAST.
MAIN CONCERN WILL CONTINUE TO BE STATUS AND TRACK OF TROPICAL
CYCLONE ERIKA. OFFICIAL FORECASTS BRING THE SYSTEM INTO S FLORIDA
BY LATE SUN...AND NORTHWARD INTO N FL/S GA VICINITY BY WED. EVEN
WITHOUT THE CYCLONE IN PLAY...IT APPEARS SUFFICIENT ATMOSPHERIC
MOISTURE WOULD PROVIDE PREMISE FOR SCATTERED DIURNAL CONVECTION
OVER OUR FA ANYWAY. DUE TO UNCERTAINTIES REGARDING POSSIBLE
IMPACT OF ERIKA ON OUR REGION...WILL CONTINUE TO MAINTAIN ONGOING
FORECAST OF CHANCE POPS...TRENDED A LITTLE HIGHER TO THE SOUTH.
GENERALLY BLENDED LATEST GUIDANCE WITH ONGOING FORECAST.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
LINGERING LOW-LEVEL MOISTURE AND NOCTURNAL COOLING MAY LEAD TO
STRATUS AND FOG DURING THE EARLY MORNING HOURS. THE NAM MOS
INDICATED MVFR OR IFR CONDITIONS 06Z TO 15Z. THE GFS MOS PLUS SREF
AND HRRR GUIDANCE GENERALLY MAINTAINED VFR CONDITIONS. WE LEANED
TOWARD THE MORE OPTIMISTIC GUIDANCE BASED ON UPPER MOISTURE
STREAMING INTO THE AREA LIMITING NET RADIATIONAL COOLING AND
SURFACE HIGH PRESSURE TO THE NORTH PUSHING DRY AIR TOWARD THE
AREA. AN INCREASE IN MOISTURE AND HEATING MAY HELP SUPPORT
THUNDERSTORMS SATURDAY AFTERNOON BUT EXPECT SCATTERED COVERAGE
WITH THE CHANCE TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT
THIS TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
339 AM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST TODAY. A
LARGE AREA OF SURFACE HIGH PRESSURE CENTERED OVER THE GREAT LAKES
REGION WILL SLIDE EAST TO THE ATLANTIC COAST FOR THE WEEKEND.
INCREASING ATMOSPHERIC MOISTURE WILL DRIFT NORTH INTO OUR REGION
THIS WEEKEND. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH
SOUTHERN FLORIDA ON SUNDAY. REFER TO THE LATEST ADVISORY ON ERIKA
ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH TODAY/...
EARLY THIS MORNING...LOW CLOUDS HAVE BEGUN TO DEVELOP EARLY THIS
MORNING...ESPECIALLY ACROSS THE WESTERN HALF OF THE FORECAST AREA
GIVEN DRY AIR ALOFT. OVERNIGHT LOWS WILL ONCE AGAIN RANGE FROM THE
MID 60S TO THE LOWER 70S.
TODAY...AN UPPER LEVEL TROUGH EXTENDING FROM THE OHIO RIVER
VALLEY TO THE GULF OF MEXICO WILL WEAKEN AND LIFT NORTH TODAY. THE
FRONTAL BOUNDARY IS EXPECTED TO REMAIN STALLED NEAR THE COAST.
SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM THE NORTH
PRODUCING NORTHEASTERLY/EASTERLY FLOW. MODELS SHOW A STRONG
GRADIENT IN PRECIPITABLE WATER FROM NORTH TO SOUTH ACROSS THE
AREA WITH THE BEST MOISTURE SOUTH. MODEL SOUNDINGS SHOW WEAK
INSTABILITY. THE HRRR AND 00Z SPC WRF SHOW ISOLATED COVERAGE.
SLIGHT CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS
APPROPRIATE. HIGH TEMPERATURES ARE FORECAST NEAR NORMAL...IN THE
UPPER 80S.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MAY STILL HAVE AN ISOLATED LINGERING SHOWER/STORM UNTIL
MIDNIGHT...THEN DRY FOR ALL AREAS THE REMAINDER OF THE NIGHT.
MOISTURE WILL BEGIN TO INCREASE ACROSS THE SOUTHERN PORTIONS OF
THE CWA SATURDAY. THIS MOISTURE INCREASE IS EXPECTED TO REMAIN
CONFINED TO THE SOUTH THROUGH THE DAY...WITH NORTHERN COUNTIES
STILL HAVING DRIER AIR IN PLACE. THIS WOULD LEAD TO THE BEST RAIN
CHANCES BEING ACROSS THE SOUTH AND SOUTH-CENTRAL COUNTIES ON
SATURDAY...WITH THE NORTHERN COUNTIES DRY OR ONLY HAVING AN
ISOLATED SHOWER/STORM. TEMPERATURES IN THE MIDDLE TO UPPER 60S
TONIGHT WITH THE DRIER AIR. SATURDAY WILL SEE HIGHS IN THE UPPER
80S. LOWS SATURDAY NIGHT MODERATE SLIGHTLY WITH THE MOISTURE
INCREASE...WITH READINGS AROUND 70.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER TROUGH WILL REMAIN TO OUR WEST WITH UPPER RIDGE REMAINING
CENTERED TO OUR E AND SE. THIS WILL CONTINUE TO DRAW MOISTURE
NORTHWARD INTO OUR REGION SUNDAY. EXPECTING TO HAVE CONTINUED
DIURNAL CONVECTION SUNDAY INTO TUESDAY WITH THIS PATTERN.
EARLY TO MID NEXT WEEK...MODELS MAINTAIN WEAK UPPER TROUGH TO OUR
WEST AND UPPER RIDGE TO OUR E AND SE. MAIN CONCERN FOR THIS TIME
PERIOD WILL BE THE EVENTUAL TRACK AND STRENGTH OF TROPICAL
CYCLONE ERIKA AS IT APPROACHES THE ATLANTIC COASTLINE. LATEST
OFFICIAL FORECAST FROM NHC BRINGS IT NW TOWARDS THE FLORIDA EAST
COAST BY LATE SUNDAY INTO EARLY TUESDAY...STRENGTHENING IT TO A
LOW END HURRICANE. THERE CONTINUES TO BE LITTLE RUN TO RUN
CONSISTENCE WITH THE LONGER RANGE MODELS...ESPECIALLY WITH THE
TRACK...AND WITH THE LARGE MODEL SPREAD...CONFIDENCE IS LOW OUT IN
THE LONG TERM. PLEASE SEE THE NHC FORECAST FOR LATEST DISCUSSION
AND TRACK OF ERIKA. FOR NOW...DUE TO UNCERTAINTIES REGARDING IMPACT
FOR OUR AREA...WILL CONTINUE TO MAINTAIN CHANCE POPS.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
NOCTURNAL COOLING AND LOW-LEVEL MOISTURE SHOULD LEAD TO STRATUS
AND FOG EARLY THIS MORNING. STRATUS IS FAVORED INSTEAD OF FOG
BECAUSE OF WIND. HEATING AND MIXING SHOULD BRING IMPROVEMENT
DURING THE DAY. LEANED TOWARD THE SLOWER NAM MOS TIMING BECAUSE
THIS GUIDANCE DID BETTER THE PREVIOUS DAY. ANOTHER SLIGHT CHANCE
OF DIURNAL CONVECTION AT THE TERMINALS THIS AFTERNOON/EVENING...ALTHOUGH
CONFIDENCE REMAINS TOO LOW TO INCLUDE IN CURRENT ISSUANCE. WINDS
WILL CONTINUE OUT OF THE NORTHEAST/EAST TODAY AT 10 KNOTS OR
LESS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
312 AM EDT FRI AUG 28 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED NEAR THE COAST TODAY. A
LARGE AREA OF SURFACE HIGH PRESSURE CENTERED OVER THE GREAT LAKES
REGION WILL SLIDE EAST TO THE ATLANTIC COAST FOR THE WEEKEND.
INCREASING ATMOSPHERIC MOISTURE WILL DRIFT NORTH INTO OUR REGION
THIS WEEKEND. TROPICAL CYCLONE ERIKA IS EXPECTED TO APPROACH
SOUTHERN FLORIDA ON SUNDAY. REFER TO THE LATEST ADVISORY ON ERIKA
ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.NEAR TERM /THROUGH TODAY/...
EARLY THIS MORNING...LOW CLOUDS HAVE BEGUN TO DEVELOP EARLY THIS
MORNING...ESPECIALLY ACROSS THE WESTERN HALF OF THE FORECAST AREA
GIVEN DRY AIR ALOFT. OVERNIGHT LOWS WILL ONCE AGAIN RANGE FROM THE
MID 60S TO THE LOWER 70S.
TODAY...AN UPPER LEVEL TROUGH EXTENDING FROM THE OHIO RIVER
VALLEY TO THE GULF OF MEXICO WILL WEAKEN AND LIFT NORTH TODAY. THE
FRONTAL BOUNDARY IS EXPECTED TO REMAIN STALLED NEAR THE COAST.
SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE IN FROM THE NORTH
PRODUCING NORTHEASTERLY/EASTERLY FLOW. MODELS SHOW A STRONG
GRADIENT IN PRECIPITABLE WATER FROM NORTH TO SOUTH ACROSS THE
AREA WITH THE BEST MOISTURE SOUTH. MODEL SOUNDINGS SHOW WEAK
INSTABILITY. THE HRRR AND 00Z SPC WRF SHOW ISOLATED COVERAGE.
SLIGHT CHANCE POPS MAINLY SOUTHERN FORECAST AREA STILL SEEMS
APPROPRIATE. HIGH TEMPERATURES ARE FORECAST NEAR NORMAL...IN THE
UPPER 80S.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MODELS CONTINUE TO INDICATE MAIN UPPER TROUGH JUST TO OUR WEST
WILL GRADUALLY WEAKEN AND LIFT NORTH THROUGH THE PERIOD...LEAVING
BEHIND A WEAK CUT OFF LOW NEAR THE NORTHERN GULF OF MEXICO...WHILE
UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO BUILD WESTWARD
TOWARDS THE SE COAST. THIS IS EXPECTED TO LEAD TO BAND OF BETTER
MOISTURE AND OLD SURFACE BOUNDARIES CURRENTLY TO OUR SOUTH TO
GRADUALLY DRIFT NORTH INTO OUR REGION SATURDAY. MAIN DIFFERENCE
WITH LATEST MODEL RUNS IS A LITTLE SLOWER TIMING WITH MOISTURE
INCREASE...AND MAINLY RELEGATING BEST MOISTURE TO THE S AND W
FA...AND MAINTAINING RELATIVELY DRY AIR OVER THE N FA...AS SURFACE
HIGH REMAINS ANCHORED OVER THE MID ATLANTIC RIDGING INTO THE
WESTERN CAROLINAS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER TROUGH WILL REMAIN TO OUR WEST WITH UPPER RIDGE REMAINING
CENTERED TO OUR E AND SE. THIS WILL CONTINUE TO DRAW MOISTURE
NORTHWARD INTO OUR REGION SUNDAY. SO...WILL MAINTAIN TREND TOWARDS
INCREASING POPS.
EARLY TO MID NEXT WEEK...MODELS MAINTAIN WEAK UPPER TROUGH TO OUR
WEST AND UPPER RIDGE TO OUR E AND SE. MAIN CONCERN FOR THIS TIME
PERIOD WILL BE TROPICAL CYCLONE ERIKA. LATEST OFFICIAL FORECAST
FROM NHC BRINGS IT NW TOWARDS THE FLORIDA EAST COAST BY LATE
SUNDAY INTO EARLY TUESDAY...STRENGTHENING IT TO A LOW END
HURRICANE. GENERAL MODEL CONSENSUS HAS IT DRIFTING TO THE NORTH OR
NE THEREAFTER. FOR NOW...DUE TO UNCERTAINTIES REGARDING IMPACT
FOR OUR FA...WILL CONTINUE TO MAINTAIN CHANCE POPS.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
NOCTURNAL COOLING AND LOW-LEVEL MOISTURE SHOULD LEAD TO STRATUS
AND FOG EARLY THIS MORNING. STRATUS IS FAVORED INSTEAD OF FOG
BECAUSE OF WIND. HEATING AND MIXING SHOULD BRING IMPROVEMENT
DURING THE DAY. LEANED TOWARD THE SLOWER NAM MOS TIMING BECAUSE
THIS GUIDANCE DID BETTER THE PREVIOUS DAY. ANOTHER SLIGHT CHANCE
OF DIURNAL CONVECTION AT THE TERMINALS THIS AFTERNOON/EVENING...ALTHOUGH
CONFIDENCE REMAINS TOO LOW TO INCLUDE IN CURRENT ISSUANCE. WINDS
WILL CONTINUE OUT OF THE NORTHEAST/EAST TODAY AT 10 KNOTS OR
LESS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING FOG AND STRATUS PLUS AFTERNOON AND EVENING SCATTERED
THUNDERSTORMS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
903 PM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 900 PM CDT SAT AUG 29 2015
A LINGERING BAND OF SHOWERS WILL CONTINUE ACROSS CENTRAL AND
EASTERN ILLINOIS THIS EVENING, THEN BEGIN TO PROGRESS EAST AFTER
MIDNIGHT. THE UPPER LEVEL TROUGH AXIS EXTENDS ACROSS IL FROM NE TO
SW, AND WILL BE THE FOCUS FOR THE CONTINUED CHANCES OF PRECIP
OVERNIGHT. CLOUDS WILL PRIMARILY DOMINATE THE SKIES OVERNIGHT, BUT
PATCHES OF CLEARING ARE SHOWING UP IN EASTERN IOWA AND FAR WESTERN
IL ON THE LATEST SATELLITE IMAGES. ANY CLEARING NW OF THE IL RIVER
WILL LIKELY RESULT IN FOG FORMATION, WITH SOME AREAS SEEING DENSE
FOG. HAVE LEFT A MENTION OF FOG FOR NW OF THE IL RIVER, BUT THERE
IS SOME INDICATIONS IN THE HRRR AND RAP THAT THE FOG COULD AFFECT
SPOTTY AREAS IN THE REMAINDER OF OUR FORECAST AREA. FOR NOW, WILL
NOT INCLUDE FOG EVERYWHERE, BUT WILL WATCH CLOSELY FOR ANY
CLEARING IN THE CLOUDS EAST OF THE IL RIVER, WHICH WOULD INCREASE
FOG POTENTIAL THERE.
LOW TEMPS WILL BE MAINLY HELD IN THE MID 60S DUE TO CLOUD COVER
AND MINIMAL AIRMASS CHANGE OVERNIGHT UNDER LIGHT AND VARIABLE
WINDS. UPDATED THE WEATHER/POP/SKY GRIDS TO MATCH EXPECTED TRENDS.
THE REMAINDER OF THE FORECAST INFO APPEARS ON TRACK.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 228 PM CDT SAT AUG 29 2015
LATEST SURFACE MAP SHOWING FRONTAL BOUNDARY ARCING FROM THE
NORTHEAST TIP OF ILLINOIS TO EAST CENTRAL IOWA...BEFORE EXTENDING
SOUTHWEST INTO SOUTHEAST KANSAS. PRECIPITATION HAS LARGELY REMAINED
LIGHT AND SCATTERED...AND HAS BEEN MOSTLY EAST OF I-55 THE LAST
SEVERAL HOURS. DECENT SLUG OF DRY AIR ALOFT SEEN ON WATER VAPOR
IMAGERY SOUTH OF A SHORTWAVE...WHICH IS CURRENTLY DROPPING INTO
SOUTHERN IOWA. SHORT-RANGE MODEL GUIDANCE IS HAVING A BIT OF
DIFFICULTY AS TO THE AMOUNT OF REDEVELOPMENT...BUT THE HRRR IS
PERFORMING HALFWAY DECENTLY AND CONTINUES TO SUGGEST MAINLY SCATTERED
SHOWERS. THUNDER HAS BEEN STAYING AWAY FROM OUR AREA SO FAR...AND
WHILE MESOANALYSIS SHOWS RESPECTABLE CAPE VALUES OF 1000-1500 J/KG
THIS AFTERNOON...MID LEVEL LAPSE RATES ARE FAIRLY MODEST. THEREFORE
WILL CONTINUE MENTION WITH ONLY ISOLATED THUNDERSTORMS THROUGH
TONIGHT...WITH THE THREAT DIMINISHING FROM NORTHWEST TO SOUTHEAST.
SOME CONCERNS LATER IN THE NIGHT WITH POTENTIAL FOR SOME FOG...
MAINLY ACROSS THE NORTHWEST CWA. STILL QUITE A BIT OF LOWER
STRATOCUMULUS ACROSS MOST OF IOWA AND WISCONSIN. LATEST RAP MODEL
GUIDANCE SUGGESTS THIS CONTRACTING SOME MORE OVER THE NEXT SEVERAL
HOURS...BEFORE SIGNIFICANTLY EXPANDING AGAIN THIS EVENING WITH HIGH
PRESSURE EXPANDING OVER THE MIDWEST. MUCH OF THE AREA UNDERNEATH
THIS HIGH SAW FROM 1 TO SEVERAL INCHES OF RAIN IN THE LAST COUPLE
DAYS...AND IS MOST FAVORED FOR DENSE FOG POTENTIAL. HOWEVER...THE
RAP SHOWS THE FOG FIELD OOZING SOUTHWARD AFTER MIDNIGHT...PERHAPS AS
FAR AS PEORIA. THAT AREA ALREADY HAD PATCHY FOG IN THE GRIDS...BUT
AM THINKING IT WILL BE A BIT MORE WIDESPREAD AND WILL GO WITH AREAS
OF FOG INSTEAD.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 228 PM CDT SAT AUG 29 2015
SHOWERS AND ISOLATED THUNDERSTORMS COULD LINGER IN THE SOUTHEASTERN
PART OF THE CWA SUNDAY MORNING BUT THEN SPREAD BACK WEST
SOME...COVERING THE EASTERN HALF OF THE CWA...MAINLY EAST OF I-55.
THIS SHOULD BE THE END OF THE PCPN AS THE FRONTAL SYSTEM DIMINISHES
OVER THE AREA REMAINDER OF THE WEEKEND. FOG AND LOWER CLOUDS WILL
SEEN THIS MORNING ALONG AND BEHIND THE FRONT...SO THINKING IS THAT
THE FOG WILL CONTINUE INTO THE FIRST FEW HOURS OF SUNDAY MORNING.
HAVE INCLUDED A SLIGHT CHANCE OF SHOWERS FOR SUNDAY NIGHT...AGAIN
MAINLY EAST OF I-55 TIL MIDNIGHT...AND THEN IN THE EXTREME SOUTHEAST
AFTER MIDNIGHT.
BEYOND THIS UPPER LEVEL RIDGING WILL BUILD INTO THE NORTHERN PLAINS
AND NORTHERN MISS VALLEY. ON THE SFC...HIGH PRESSURE RIDGING WILL
BUILD BACK TOWARD THE AREA FROM THE SOUTHEAST. THE COMBINATION OF
THE TWO SHOULD HELP TO KEEP THE AREA DRY THROUGH THE BEGINNING OF
THE WEEK. TEMPS WILL BE IN THE LOWER TO MIDDLE 80S TOMORROW...BUT
THEN WARM INTO THE MIDDLE TO UPPER 80S FOR MONDAY INTO TUESDAY.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY...THOUGH SOME OF THE
MODELS CONTINUE TO BRING SOME SPOTTY POPS IN THE AREA DUE TO
SOUTHERLY FLOW ON THE SFC. FOR NOW...WILL ONLY HAVE SLIGHT CHC POPS
FOR WED ACROSS AREAS ALONG AND NORTH OF I-74 AND EAST OF I-57.
REMAINDER OF THE WEEK WITH BE DRY...EVEN INTO THE BEGINNING OF THE
LABOR DAY WEEKEND. TEMPS WILL REMAIN WELL ABOVE NORMAL IN THE
EXTENDED PERIOD SO HEAT COULD BE AN ISSUE LATER...BUT DEWPOINTS WILL
REMAIN LOW SO HEAT INDEX VALUES ARE NOT EXPECTED TO GET OVER 100
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 628 PM CDT SAT AUG 29 2015
A DECAYING COLD FRONT IS PASSING ACROSS THE FORECAST AREA EARLY
THIS EVENING, AND WILL CAUSE THE WINDS TO BECOME LIGHT AND
VARIABLE FOR SEVERAL HOURS THIS EVENING AND POSSIBLY MOST OF THE
NIGHT. THAT WILL LEAD TO THE POTENTIAL FOR AREAS OF DENSE FOG TO
FORM, ESPECIALLY FARTHER NW AROUND PIA. FOG FOR THE OTHER TERMINAL
SITES SHOULD REMAIN MVFR, BUT HRRR AND RAP OUTPUT KEEP EXPANDING
THE AREA OF DENSE FOG FARTHER SOUTH, SO WILL MONITOR FOG CLOSELY
FOR POSSIBLE VIS REDUCTION FOR THE OTHER TERMINALS.
TOMORROW MORNING WINDS ARE FORECAST TO RETURN TO THE SOUTH-
SOUTHWEST AND REMAINING LESS THAN 10 KT THROUGH THE DAY.
CLOUDS WILL POSSIBLE DIP TO LIFR AT PIA, WITH MVFR CLOUDS AT THE
OTHER TAF SITES FOR A FEW HOURS AFTER SUNRISE. THEN LOW CLOUDS
SHOULD CLEAR OUT AS DIURNAL MIXING INCREASES AND DRY AIR WASHES
OUT THE LOW LEVEL MOISTURE.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
628 PM CDT SAT AUG 29 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 228 PM CDT SAT AUG 29 2015
LATEST SURFACE MAP SHOWING FRONTAL BOUNDARY ARCING FROM THE
NORTHEAST TIP OF ILLINOIS TO EAST CENTRAL IOWA...BEFORE EXTENDING
SOUTHWEST INTO SOUTHEAST KANSAS. PRECIPITATION HAS LARGELY REMAINED
LIGHT AND SCATTERED...AND HAS BEEN MOSTLY EAST OF I-55 THE LAST
SEVERAL HOURS. DECENT SLUG OF DRY AIR ALOFT SEEN ON WATER VAPOR
IMAGERY SOUTH OF A SHORTWAVE...WHICH IS CURRENTLY DROPPING INTO
SOUTHERN IOWA. SHORT-RANGE MODEL GUIDANCE IS HAVING A BIT OF
DIFFICULTY AS TO THE AMOUNT OF REDEVELOPMENT...BUT THE HRRR IS
PERFORMING HALFWAY DECENTLY AND CONTINUES TO SUGGEST MAINLY SCATTERED
SHOWERS. THUNDER HAS BEEN STAYING AWAY FROM OUR AREA SO FAR...AND
WHILE MESOANALYSIS SHOWS RESPECTABLE CAPE VALUES OF 1000-1500 J/KG
THIS AFTERNOON...MID LEVEL LAPSE RATES ARE FAIRLY MODEST. THEREFORE
WILL CONTINUE MENTION WITH ONLY ISOLATED THUNDERSTORMS THROUGH
TONIGHT...WITH THE THREAT DIMINISHING FROM NORTHWEST TO SOUTHEAST.
SOME CONCERNS LATER IN THE NIGHT WITH POTENTIAL FOR SOME FOG...
MAINLY ACROSS THE NORTHWEST CWA. STILL QUITE A BIT OF LOWER
STRATOCUMULUS ACROSS MOST OF IOWA AND WISCONSIN. LATEST RAP MODEL
GUIDANCE SUGGESTS THIS CONTRACTING SOME MORE OVER THE NEXT SEVERAL
HOURS...BEFORE SIGNIFICANTLY EXPANDING AGAIN THIS EVENING WITH HIGH
PRESSURE EXPANDING OVER THE MIDWEST. MUCH OF THE AREA UNDERNEATH
THIS HIGH SAW FROM 1 TO SEVERAL INCHES OF RAIN IN THE LAST COUPLE
DAYS...AND IS MOST FAVORED FOR DENSE FOG POTENTIAL. HOWEVER...THE
RAP SHOWS THE FOG FIELD OOZING SOUTHWARD AFTER MIDNIGHT...PERHAPS AS
FAR AS PEORIA. THAT AREA ALREADY HAD PATCHY FOG IN THE GRIDS...BUT
AM THINKING IT WILL BE A BIT MORE WIDESPREAD AND WILL GO WITH AREAS
OF FOG INSTEAD.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 228 PM CDT SAT AUG 29 2015
SHOWERS AND ISOLATED THUNDERSTORMS COULD LINGER IN THE SOUTHEASTERN
PART OF THE CWA SUNDAY MORNING BUT THEN SPREAD BACK WEST
SOME...COVERING THE EASTERN HALF OF THE CWA...MAINLY EAST OF I-55.
THIS SHOULD BE THE END OF THE PCPN AS THE FRONTAL SYSTEM DIMINISHES
OVER THE AREA REMAINDER OF THE WEEKEND. FOG AND LOWER CLOUDS WILL
SEEN THIS MORNING ALONG AND BEHIND THE FRONT...SO THINKING IS THAT
THE FOG WILL CONTINUE INTO THE FIRST FEW HOURS OF SUNDAY MORNING.
HAVE INCLUDED A SLIGHT CHANCE OF SHOWERS FOR SUNDAY NIGHT...AGAIN
MAINLY EAST OF I-55 TIL MIDNIGHT...AND THEN IN THE EXTREME SOUTHEAST
AFTER MIDNIGHT.
BEYOND THIS UPPER LEVEL RIDGING WILL BUILD INTO THE NORTHERN PLAINS
AND NORTHERN MISS VALLEY. ON THE SFC...HIGH PRESSURE RIDGING WILL
BUILD BACK TOWARD THE AREA FROM THE SOUTHEAST. THE COMBINATION OF
THE TWO SHOULD HELP TO KEEP THE AREA DRY THROUGH THE BEGINNING OF
THE WEEK. TEMPS WILL BE IN THE LOWER TO MIDDLE 80S TOMORROW...BUT
THEN WARM INTO THE MIDDLE TO UPPER 80S FOR MONDAY INTO TUESDAY.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY...THOUGH SOME OF THE
MODELS CONTINUE TO BRING SOME SPOTTY POPS IN THE AREA DUE TO
SOUTHERLY FLOW ON THE SFC. FOR NOW...WILL ONLY HAVE SLIGHT CHC POPS
FOR WED ACROSS AREAS ALONG AND NORTH OF I-74 AND EAST OF I-57.
REMAINDER OF THE WEEK WITH BE DRY...EVEN INTO THE BEGINNING OF THE
LABOR DAY WEEKEND. TEMPS WILL REMAIN WELL ABOVE NORMAL IN THE
EXTENDED PERIOD SO HEAT COULD BE AN ISSUE LATER...BUT DEWPOINTS WILL
REMAIN LOW SO HEAT INDEX VALUES ARE NOT EXPECTED TO GET OVER 100
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 628 PM CDT SAT AUG 29 2015
A DECAYING COLD FRONT IS PASSING ACROSS THE FORECAST AREA EARLY
THIS EVENING, AND WILL CAUSE THE WINDS TO BECOME LIGHT AND
VARIABLE FOR SEVERAL HOURS THIS EVENING AND POSSIBLY MOST OF THE
NIGHT. THAT WILL LEAD TO THE POTENTIAL FOR AREAS OF DENSE FOG TO
FORM, ESPECIALLY FARTHER NW AROUND PIA. FOG FOR THE OTHER TERMINAL
SITES SHOULD REMAIN MVFR, BUT HRRR AND RAP OUTPUT KEEP EXPANDING
THE AREA OF DENSE FOG FARTHER SOUTH, SO WILL MONITOR FOG CLOSELY
FOR POSSIBLE VIS REDUCTION FOR THE OTHER TERMINALS.
TOMORROW MORNING WINDS ARE FORECAST TO RETURN TO THE SOUTH-
SOUTHWEST AND REMAINING LESS THAN 10 KT THROUGH THE DAY.
CLOUDS WILL POSSIBLE DIP TO LIFR AT PIA, WITH MVFR CLOUDS AT THE
OTHER TAF SITES FOR A FEW HOURS AFTER SUNRISE. THEN LOW CLOUDS
SHOULD CLEAR OUT AS DIURNAL MIXING INCREASES AND DRY AIR WASHES
OUT THE LOW LEVEL MOISTURE.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
500 PM CDT FRI AUG 28 2015
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING.
SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON.
KJB/BMD
//DISCUSSION...UPDATED 18Z...
AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS
AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD
TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY
STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS
FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE
SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK
SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS
THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY.
HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY
AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA.
GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER
LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY
MORNING/EARLY AFTERNOON.
* LOW WITH THREAT OF THUNDER DURING THE PERIOD.
* HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.
KJB/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
SUNDAY...VFR. NORTHEAST WINDS.
MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE
AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH
AFTERNOON.
IZZI
&&
.MARINE...
310 PM CDT
HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE
THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN
IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY
AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A
TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS
TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE
OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST
WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
310 PM CDT FRI AUG 28 2015
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
307 PM CDT
SATURDAY NIGHT THROUGH FRIDAY...
THE LATEST LONGER TERM GUIDANCE IS INDICATING SOME CHANGES POSSIBLE
FOR THE LONGER RANGE TRENDS FOR TEMPERATURES AND PCPN...BUT THE
EARLIER PORTION OF THE LONG TERM FORECAST IS RELATIVELY CONSISTENT
WITH PREVIOUS RUNS.
THE GENERAL TREND FOR TEMPERATURES IS STILL FOR A WARMING TREND FOR
NEXT WEEK...BUT TEMPERATURES SHOULD STILL BE SLIGHTLY BELOW NORMAL
THROUGH SUNDAY. FOR SATURDAY NIGHT AND INTO EARLY SUNDAY...THERE
SHOULD STILL BE A CHANCE OF SOME LINGERING SHOWERS OR A FEW
THUNDERSTORMS...ESPECIALLY FOR NWRN INDIANA AS THE UPPER LEVEL
SHORTWAVE RESPONSIBLE FOR FOCUSING THE CONVECTIVE ACTIVITY LIFTS
OFF TO THE EAST AND WEAKENS. BY SUNDAY...LEE TROUGHING WILL DEVELOP
OVER THE WRN PLAINS AS A NORTHERN STREAM SHORTWAVE AND AN ASSOCIATED
SFC REFLECTION DROPS OUT OF THE CANADIAN ROCKIES AND INTO THE
PRAIRIES. THE OVERALL PATTERN WILL BECOME NEARLY STATIONARY THROUGH
MUCH OF NEXT WEEK AS THE SFC HIGH REMAINS PARKED OVER THE MID
ATLANTIC REGION WHILE THE TROUGH REMAINS OVER THE PLAINS. THIS WILL
HELP AID THE WARMING TREND AS SLY WINDS TRY TO DRAW MOISTURE NWD
FROM THE GLFMEX...THOUGH WEAK SFC RIDGING THROUGH THE NRN GULF COAST
MAY CAUSE SOME DELAY IN THE MOISTURE RETURN.
THE MAIN CHANGE TO THE EXTENDED FORECAST IS RELATED TO HOW THE
MODELS NOW HANDLE THE REMNANTS OF TS ERIKA. PREVIOUS RUNS OF THE
LONGER RANGE GUIDANCE HAD PREVIOUSLY LIMITED THE WESTWARD
PROGRESSION OF THE TROPICAL SYSTEM...WHILE THE LATEST RUNS ARE
HINTING THAT ERIKA COULD TRACK FARTHER WEST. SO...WHILE THERE IS
STILL A FAIR AMOUNT OF UNCERTAINTY IN HOW FAR WEST THE PERIPHERAL
EFFECT OF THE TROPICAL SYSTEM WILL EXTEND...AND WE ARE NOT TALKING
ABOUT THE TROPICAL SYSTEM ACTUALLY MOVING ANYWHERE CLOSE TO NRN
IL/IN...RATHER THE IDEA IS THAT IF THE TROPICAL SYSTEM CAN TRACK A
LITTLE FURTHER WEST...THEN THERE WILL BE GREATER MOISTURE TRANSPORT
INTO THE MIDWEST...AND AS A RESULT...GREATER CHANCES FOR SHRA/TSRA
AND MORE CLOUD COVER THAN PREVIOUSLY ANTICIPATED. SO HAVE BACKED
OFF A COUPLE DEGREES ON MAX TEMPS THROUGH THE EXTENDED PERIOD AS
WELL AS INTRODUCING PERIODIC SLIGHT CHANCE POPS AND A BIT MORE CLOUD
COVER.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WIND SHIFT TO EAST-SOUTHEASTERLY LIKELY EARLY THIS EVENING.
* CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING.
SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON.
KJB
//DISCUSSION...UPDATED 18Z...
AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS
AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD
TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY
STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS
FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE
SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK
SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS
THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY.
HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY
AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA.
GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER
LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH WITH WIND SHIFT TO SOUTHEAST THIS EVENING...LOW WITH PRECISE
SPEEDS AND TIMING.
* MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY
MORNING/EARLY AFTERNOON.
* LOW WITH THREAT OF THUNDER DURING THE PERIOD.
* HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
SUNDAY...VFR. NORTHEAST WINDS.
MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE
AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH
AFTERNOON.
IZZI
&&
.MARINE...
310 PM CDT
HIGH PRESSURE OVER THE MID ATLANTIC REGION WILL MOVE VERY LITTLE
THROUGH THE MIDDLE OF NEXT WEEK. WEAK LOW PRESSURE OVER WESTERN
IOWA WILL WEAKEN AS IT MOVES INTO THE MIDDLE MISSISSIPPI VALLEY
AND DISSIPATES SATURDAY EVENING. ANOTHER AREA OF LOW PRESSURE IS
EXPECTED TO DROP OUT OF THE CANADIAN ROCKIES SUNDAY NIGHT WHILE A
TROUGH OF LOW PRESSURE DEVELOPS OVER THE WESTERN PLAINS. THIS
TROUGH AND THE HIGH OVER THE MID ATLANTIC REGION WILL MOVE LITTLE
OVER THE NEXT SEVERAL DAYS...KEEPING MODEST SOUTH TO SOUTHWEST
WINDS OVER THE LAKE FOR THE NEXT SEVERAL DAYS.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
250 PM CDT FRI AUG 28 2015
.SHORT TERM...
TONIGHT AND SATURDAY...
250 PM...FORECAST CONCERNS INCLUDE PRECIP COVERAGE/TIMING AND
RAINFALL AMOUNTS.
LOW PRESSURE OVER WESTERN IOWA WILL SLOWLY MOVE EAST TONIGHT AND
EVENTUALLY DISSIPATE OVER NORTHERN ILLINOIS SATURDAY. FIRST WAVE OF
PRECIP IS GENERALLY LIFTING NORTHEAST INTO SOUTHERN WISCONSIN AND
THE MODELS SEEM TO HAVE THIS HANDLED FAIRLY WELL WITH THE HRRR ALSO
SHOWING JUST ISOLATED SHOWERS/SPRINKLES INTO EARLY THIS EVENING AND
MAINLY ACROSS NORTHWEST AND NORTHERN IL. ADDITIONAL PRECIP IS
EXPECTED TO DEVELOP LATER THIS EVENING AND SPREAD NORTHEAST
OVERNIGHT INTO SATURDAY MORNING. THIS PRECIP WILL ALSO BE FOCUSED
ACROSS NORTHWEST/NORTHERN IL...INTO SOUTHERN WI. MODEL QPF AMOUNTS
NEAR THE IL/WI STATE LINE ARE IN THE 1 TO 1.5 INCH RANGE. THESE
AMOUNTS HAVE BEEN CONSISTENT BETWEEN RUNS AND VARIOUS MODELS SO IT
IS LIKELY SOME AREAS WILL SEE OVER AN INCH OF RAIN. HOWEVER...THESE
AMOUNTS APPEAR TO DROP OFF QUICKLY BETWEEN I-88 AND I-80 WITH MUCH
OF THE SOUTHEAST THIRD OR HALF OF THE CWA POSSIBLY STAYING DRY INTO
SATURDAY MORNING. INSTABILITY IS LIMITED AND LIGHTNING HAS BEEN
CONFINED TO THE STRONGEST STORMS/CONVECTION. THUNDER IS CERTAINLY
POSSIBLE TONIGHT BUT OVERALL COVERAGE SHOULD BE LIMITED AND HELD
SLIGHT CHANCE MENTION OF THUNDER TO HIGHER POP AREAS.
AFTER THE MAIN AREA OF RAIN MOVES NORTHEAST SATURDAY MORNING...
PRECIP ACROSS THE REST OF THE CWA WILL BE MORE SCATTERED...OR
ISOLATED...INTO THE LATE MORNING/EARLY AFTERNOON. APPEARS THERE
COULD BE NEW DEVELOPMENT IN THE EARLY/MID AFTERNOON BUT COVERAGE
POSSIBLY STILL JUST SCATTERED. THUS DIDN/T MAKE TOO MANY CHANGES
FROM CURRENT POPS IN THE 40-50 PERCENT RANGE.
TEMPS WILL ONLY SLOWLY FALL INTO THE LOWER/MID 60S TONIGHT AND HIGHS
ON SATURDAY WILL BE DEPENDENT ON PRECIP COVERAGE AND CLOUD COVER.
CURRENT FORECAST OF MID 70S NORTH TO LOWER 80S SOUTHEAST WILL
NEED SOME SUN TO OCCUR. SOUTHEASTERLY WINDS WILL KEEP THE IL SHORE
A BIT COOLER. CMS
&&
.LONG TERM...
344 AM CDT
SUNDAY THROUGH THURSDAY...
END OF THE WEEKEND INTO THE START OF NEXT WEEK WILL SEE THIS
MID/UPPER TROUGH SLOWLY EXITING TO THE EAST...WITH CLOUDS AND
PRECIP CHANCES LIKEWISE EXITING DURING THE DAY SUNDAY. GUIDANCE
VARIES TO THE EVOLUTION OF THIS EXITING SYSTEM BUT LIKELY SCENARIO
FOR OUR AREA WILL BE FOR UPPER LEVEL RIDGING WITH WEAKER FLOW
ALOFT. CONDITIONS WILL LIKELY BE ON THE DRY SIDE THROUGH EARLY
NEXT WEEK...OUTSIDE OF SOME POSSIBLE AFTERNOON THUNDERSTORMS ON
TUESDAY DUE TO INCREASING MOISTURE/INSTABILITY...WHILE A WARMING
TREND CONTINUES.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WIND SHIFT TO EAST-SOUTHEASTERLY LIKELY EARLY THIS EVENING.
* CHANCE OF SHRA/SLIGHT CHANCE OF TS TONIGHT INTO SAT MORNING.
SLIGHTLY BETTER CHANCE OF THUNDER SATURDAY AFTERNOON.
KJB
//DISCUSSION...UPDATED 18Z...
AN ATMOSPHERIC DISTURBANCE...CURRENTLY DRIVING AN AREA OF SHOWERS
AND EMBEDDED STORMS OVER IOWA...WILL GRADUALLY SHIFT EASTWARD
TONIGHT. HOWEVER...IT APPEARS THE MAIN FOCUS FOR SHOWERS AND ANY
STORMS MAY LARGELY REMAIN NORTH OF THE EASTERN TERMINALS...ACROSS
FAR NORTHERN ILLINOIS AND INTO WISCONSIN. BETTER CHANCES OF MORE
SUBSTANTIAL SHOWERS LOOKS TO ENTER THE PICTURE AFTER DAYBREAK
SATURDAY...AND CONTINUING AT TIMES INTO THE AFTERNOON. IT APPEARS
THE THUNDER THREAT WILL BE LOW WITH MUCH OF THIS ACTIVITY.
HOWEVER...THERE WILL BE A SLIGHT BETTER CHANCE OF THUNDER SUNDAY
AFTERNOON AS A FRONTAL ZONE SAGS SOUTHEASTWARD OVER THE AREA.
GIVEN THIS...I HAVE OPTED TO ADD A PROB30 FOR A PERIOD OF THUNDER
LATER SATURDAY AFTERNOON AT THE END OF THE 30 HOUR ORD TAF.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH WITH WIND SHIFT TO SOUTHEAST THIS EVENING...LOW WITH PRECISE
SPEEDS AND TIMING.
* MEDIUM WITH PRECIP CHANCES/TIMING...ESPECIALLY SATURDAY
MORNING/EARLY AFTERNOON.
* LOW WITH THREAT OF THUNDER DURING THE PERIOD.
* HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SLIGHT CHANCE OF TSRA...OTHERWISE VFR.
SUNDAY...VFR. NORTHEAST WINDS.
MONDAY THROUGH THURSDAY...VFR. SOUTHERLY WINDS...POSSIBLE
AFTERNOON WIND SHIFTS TO EASTERLY WITH LAKE BREEZES EACH
AFTERNOON.
IZZI
&&
.MARINE...
157 AM CDT
FAIRLY TYPICAL SUMMER PATTERN LIKELY TO PERSIST THROUGH THE
UPCOMING WEEK WITH GENERALLY NO SIGNIFICANT WINDS/WAVES
ANTICIPATED. WEAK SURFACE LOW OVER THE CORN BELT WILL TRACK SLOWLY
EAST INTO NORTHERN ILLINOIS/SOUTHERN WISCONSIN THROUGH SATURDAY
BEFORE DISSIPATING. THE MAIN RESULT WILL BE A BACKING OF WINDS TO
EASTERLY OVER SOUTHERN PORTIONS OF THE LAKE LATER TODAY INTO THIS
EVENING BEFORE VEERING SOUTHERLY AGAIN LATE TONIGHT AND FRESHENING
UP JUST A BIT...BUT LIKELY LESS THAN 20KT.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
243 PM CDT FRI AUG 28 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 243 PM CDT FRI AUG 28 2015
AFTERNOON SURFACE MAP SHOWING LOW PRESSURE CENTERED NEAR OMAHA, WITH
A WARM FRONT EXTENDING NORTHEAST ACROSS IOWA AND A COLD FRONT INTO
CENTRAL KANSAS. MAIN ACTIVITY OF SHOWERS AND THUNDERSTORMS HAS BEEN
CLOSER TO THE WARM FRONT AND TRACKING NORTH OF OUR FORECAST AREA. A
GENERAL EASTWARD PROGRESSION OF THE BOUNDARIES IS EXPECTED OVER THE
NEXT SEVERAL HOURS, WITH THE COLD FRONT APPROACHING THE
ILLINOIS/IOWA BORDER TOWARD 3-4 AM. FORECAST SOUNDINGS ARE RATHER
DRY BELOW 12,000 FEET FROM ABOUT PEORIA EAST AND SOUTH, AND AM
STARTING TO GET CONCERNED THAT THERE WILL BE LITTLE MORE THAN
ISOLATED SHOWERS BETWEEN I-55 AND THE ILLINOIS RIVER TONIGHT.
HOWEVER, THE HRRR AND ARW MODELS ARE A BIT MORE AGGRESSIVE WITH
SHOWERS MOVING INTO THIS AREA AFTER 3 AM, SO WILL MAINTAIN CHANCE
POP`S ACROSS THE ILLINOIS RIVER VALLEY MAINLY FROM LATE EVENING
THROUGH OVERNIGHT. INSTABILITY IS A LITTLE MORE SPARSE THOUGH, WITH
THE CURRENT THUNDER ACTIVITY MAINLY NEAR THE UPPER LEVEL DISTURBANCE
TRACKING ACROSS CENTRAL IOWA, AND HAVE TRIMMED BACK THE THUNDER
POTENTIAL TO MAINLY WEST OF THE RIVER. OTHERWISE, HAVE MAINLY GONE
DRY EAST OF I-55. MILDER CONDITIONS EXPECTED OVERNIGHT WITH CLOUD
COVER MUCH MORE EXTENSIVE AND A SOUTHERLY FLOW, WITH MOST AREAS
DIPPING INTO THE MID 60S.
&&
.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 243 PM CDT FRI AUG 28 2015
LOW PRESSURE AREA AND ASSOCIATED FRONT WEST OF THE AREA WILL
CONTINUE TO SLOWLY MOVE EAST AND INTO THE CWA DURING THE WEEKEND.
HOWEVER...VERY LITTLE SUPPORT FOR THIS SYSTEM AS IT MOVES EAST SO
ALL MODELS HAVE THIS SYSTEM WEAKENING AS IT MOVES INTO THE AREA.
THEREFORE...WILL ONLY HAVE CHANCE POPS FOR SAT MORNING WEST OF I-55
AND THEN MOVE POPS EAST DURING THE AFTERNOON BUT REMAINING MAINLY
NORTH OF I-70 AS FRONT CONTINUES TO WEAKEN AND BECOME SOMEWHAT
PARALLEL TO THE FLOW AND VERY LACKING ON CONVERGENCE/SUPPORT. CHANCE
POPS FOR SAT NIGHT WILL CONTINUE AS THE UPPER LEVEL WAVE SHIFTS EAST
ACROSS THE AREA. PCPN WILL BE MAINLY SHOWERS AND ISOLATED
THUNDERSTORMS...DUE TO LACK OF FORCING AND INSTABILITY. BY
SUNDAY...THE WAVE SHOULD BE VERY WEAK AND EAST OF THE CWA...SO WILL
ONLY HAVE SLIGHT CHANCE POPS. FOR REMAINDER OF THE WEEKEND AND INTO
THE BEGINNING OF NEXT WEEK...DRY CONDITIONS CAN BE EXPECTED AS HIGH
PRESSURE BEGINS TO BUILD IN THE WEST AND PUSH INTO THE NORTHERN PART
OF THE AREA.
BEGINNING TUE AND THROUGH MOST OF THE WEEK...A COUPLE OF MODELS
BRING REMNANTS OF TS ERIKA INTO THE AREA. HOWEVER...THIS IS
DEPENDENT ON WHERE THE TS GOES. AND IT IS FAR ENOUGH AWAY IN TIME
THAT WILL JUST KEEP CLOSE TO WHAT THE CRINT HAS...AND THAT IS JUST
SLIGHT CHANCE POPS IN SOME AREAS FOR WED THROUGH THUR. SLIGHT CHANCE
POPS WILL BE IN THE GRIDS BUT NOT MENTIONED IN THE WORDED FORECAST.
TEMPS THROUGH THE WEEKEND WILL BE TEMPERED DUE TO CLOUD COVER AND
SCATTERED PCPN...BUT STILL EXPECTING THEM TO RISE INTO THE 80S FOR
THE WEEKEND. BY NEXT WEEK...WITH UPPER LEVEL RIDGING BUILDING INTO
THE AREA AND DEWPOINTS BEING DRIER...EXPECTING TEMPS TO RISE INTO
THE UPPER 80S TO AROUND 90 FOR THE ENTIRE WEEK. THIS WILL BE MUCH
ABOVE NORMAL FOR THE BEGINNING OF SEPT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1227 PM CDT FRI AUG 28 2015
MAIN QUESTION FOR THIS TAF SET WILL BE THE ARRIVAL OF ANY
SHOWERS/STORMS. FORECAST SOUNDINGS ARE SHOWING QUITE A BIT OF DRY
AIR BELOW 10KFT MOST OF THE PERIOD...FINALLY MOISTENING UP AROUND
KPIA TOWARD SUNRISE. HOWEVER...INSTABILITY REMAINS RATHER
LIMITED...SO WILL KEEP MENTION OF THE VCSH THERE WITHOUT ANY
MENTION OF THUNDER. THE REMAINDER OF CENTRAL ILLINOIS WILL MAINLY
SEE A GRADUAL LOWERING OF HIGH CLOUDS THROUGH THE NEXT 24
HOURS...WITH SOUTH-SOUTHEAST WINDS TRENDING MORE SOUTH-SOUTHWEST
BY MID MORNING SATURDAY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS DES MOINES IA
358 PM CDT FRI AUG 28 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 358 PM CDT FRI AUG 28 2015
HEAVY RAIN WILL PERSIST ACROSS THE NORTHEAST THROUGH THE
EVENING. LATEST HRRR RUN KEEPS CONVECTION GOING IN THE FAR EAST
THROUGH 04-05Z TIME FRAME AND LEANED TOWARD THIS SOLUTION FOR
POPS/WX. THE WARM RAIN PROCESSES CURRENTLY AFFECTING THE FLASH FLOOD
WARNED AREAS ARE PRODUCING 2-4 INCH PER HOUR RAINFALL RATES. STRONG
DEEP MOISTURE CONVERGENCE OVER THE WATERLOO AREA WITH ROUGHLY 1.5-2
INCH PRECIPITABLE WATER AND WARM CLOUD DEPTHS TO AROUND 4000 METERS
IS ENOUGH TO CONTINUE THE HEAVY RAIN THREAT BEFORE SURFACE LOW IN
WESTERN IOWA PUSHES FURTHER EAST LATER THIS EVENING. POTENTIAL FOR
HEAVY RAIN TO CONTINUE IN THE EAST TO NORTHEAST SECTIONS OF THE
FORECAST AREA THROUGH 03Z TONIGHT...TO COINCIDE WITH THE LATEST HRRR
THINKING. OTHER CONCERN IS FOG OVERNIGHT WITH PLENTY OF MOISTURE AND
VERY LITTLE FLOW AT THE SURFACE A WEAK SURFACE RIDGE BUILDS INTO
WESTERN IOWA. HAVE MENTIONED PATCHY FOG PAST 09Z WEST OF I-35.
.LONG TERM /SATURDAY THROUGH FRIDAY/...
ISSUED AT 358 PM CDT FRI AUG 28 2015
THE WEATHER WILL GENERALLY BE QUIET IN THE LONGER TERM WITH UPPER
RIDGING BUILDING INTO THE CENTRAL UNITED STATES. THICKNESSES WILL
INCREASE WITH TEMPERATURES CORRESPONDINGLY RESPONDING WITH HIGHS
CLIMBING ABOVE NORMAL...LIKELY TOWARD 90 BY EARLY NEXT
WEEK...ESPECIALLY IN THE SOUTH AND WEST. BOTH GFS AND EURO
INDICATED A WEAK SYSTEM PULLING NORTHEAST ON TUESDAY INTO THE
PLAINS WHICH MAY BRING THE THREAT OF ISOLATED THUNDER INTO THE
NORTHWEST PORTIONS OF IOWA BY LATER IN THE DAY INTO TUESDAY NIGHT.
OTHERWISE...THE RIDGE WILL REMAIN IN PLACE INTO LATE IN THE WEEK
WITH THE VERY WARM TEMPERATURES AND LITTLE THREAT OF PRECIPITATION.
&&
.AVIATION...28/18Z
ISSUED AT 105 PM CDT FRI AUG 28 2015
IFR TO MVFR STRATUS WILL PERSIST THROUGH THE AFTERNOON AND INTO
THE OVERNIGHT HOURS. MCW/ALO HAVE THE BEST SHOT OF IFR VIS WRT TO
HEAVY RAIN THIS AFTERNOON. OTHERWISE...EXPECTING FOG/STRATUS TO
CONTINUE OVERNIGHT INTO SATURDAY MORNING AND HAVE MENTION OF IFR
CONDITIONS PAST 06Z SATURDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...PODRAZIK
LONG TERM...COGIL
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS TOPEKA KS
323 AM CDT FRI AUG 28 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 249 AM CDT FRI AUG 28 2015
Early this morning an upper trough extended from northwest IA
southwest across central KS. Ascent ahead of the trough axis
combined with isentropic lift above 850mb level was causing numerous
showers and isolated thunderstorms across the western and northern
counties of the CWA. MUCAPES were only around 500 J/KG, thus the
elevated thunderstorms will remain rather weak through the morning
hours. The scattered to numerous showers along with isolated
elevated thunderstorms will continue to move east across northeast
and east central KS through the morning hours. We may see a break in
the showers and thunderstorms during the early afternoon hours as
the stronger isentropic lift shifts northeast into northern MO and
eastern IA.
A second H5 trough will dig southeast across eastern KS later this
afternoon along with a surface cold front located across central NE
and northwest KS. As the surface front pushes southeast across
northeast and east central KS, scattered showers and thunderstorms
will develop along the surface front. There may even be some post
frontal showers and thunderstorms due to the stronger ascent ahead
of the H5 trough digging southeast on the back side of a developing
closed upper low across northeast IA and southeast MN.
If we see some insolation then MLCAPES may increase to around 1500
J/KG. The sfc to 6 KM effective shear will remain rather weak, under
20 KTS, through the day as the low-level flow veer to the southwest
ahead of the surface cold front. There could be a few strong storms
that may produce small hail and gusty winds if the atmosphere
destabilizes ahead of the surface front. The surface front and H5
trough will pass southeast of the CWA after 6Z. There could be a few
lingering showers northwest of the front across the extreme southeast
counties through the early morning hours of Saturday but these
showers should shift southeast of the CWA before 12Z SAT.
Highs Today will be dependent on the degree of insolation. If we
remain cloudy through the day then highs may only reach the upper
70s to lower 80s. Areas that see more insolation may reach the mid
80s. Tonight lows will drop into the lower to mid 60s.
.LONG TERM...(Saturday THROUGH Thursday)
ISSUED AT 249 AM CDT FRI AUG 28 2015
Saturday...Weak shortwave trough drifts slowly off to the
southeast, ending precip chances in east central KS, although some
clouds could linger in that area through Saturday night.
Saturday night through Sunday night...Upper ridge builds east
during this time as previously mentioned remnant vort max weakens
over the Ozark area. Would expect dry conditions through this time
period...although isolated showers could form in southeast KS,
with a small chance they could affect areas mainly south of I35.
Monday through Tuesday night...Upper ridge is flattened by a
shortwave trough that moves from the central Rockies to the Upper
Midwest. Main dynamics/lift with this trough should be to our
north but both GFS and ECMWF do develop QPF in north central/far
northeast KS Tuesday night. Have added low POPS for that area
overnight.
Wednesday through Thursday...Behind this trough, persistent low-
level warm advection helps build upper ridge back over the eastern
Plains into the Upper Midwest, with seasonably warm max
temperatures expected to be in the lower 90s each day.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT)
ISSUED AT 1152 PM CDT THU AUG 27 2015
Area of showers and thunderstorms over north central KS late this
evening should move east through northeast Kansas through Friday
morning. Preferred the latest HRRR and 00Z 12KM NAM concerning
the movement of the precipitation. Given the limited instability,
precipitation will likely be showers with embedded thunderstorms
so forecasted showers at KTOP/KFOE. 00z NAM sounding for Friday
afternoon suggest surface based thunderstorms are possible as weak
boundary approaches. Kept VCTS for this possibility. Otherwise,
VFR conditions.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gargan
LONG TERM...GDP
AVIATION...Johnson
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1200 AM CDT FRI AUG 28 2015
...Update to aviation forecast discussion...
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 242 PM CDT THU AUG 27 2015
Thunderstorm chances and degree of strength remain the challenges
in the short term. Morning convection out east provided a robust
outflow boundary that continues to reinforce in the east and
advance into south central Kansas at this hour. Clouds have also
lessened instability to the east, while elevated weak echoes have
started to develop out ahead of the surface low in southwest
nebraska into NW Kansas. True surface front appears to be just
through Goodland with dryline extending to the SSE, and a weak
prefrontal trof having become commingled with the outflow across
the central part of the state. Clouds and outflow has likely
impacted surface based instability, although lapse rates aloft
remain steep above the warm nose.
For the evening hours, expect weak echoes to continue to develop
over Central Kansas and move eastward with most activity remaining
east of Manhattan through midnight. CAPE dissipates quickly as the
evening progresses, and wind shear remains on the low end around
30kts 0-6km. NAM soundings suggest some help from LLJ in getting
storms started overnight, and along with the weakly defined front
moving through the area, should bring storms through overnight
and into Friday afternoon. A few of the storms could be severe,
but think SPC outlook keeping marginal threat in the northwest
part of our area is a good representation. Lows tonight with
clouds and precip remain around 70, with highs tomorrow in the low
to middle 80s.
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 242 PM CDT THU AUG 27 2015
Friday night through Sunday
By Friday evening, sfc frontal boundary is similar with guidance
positioning southwest to northeast over east central areas of the
CWA. While subsidence increases behind the trough over north central
areas, it is possible scattered convection could continue to develop
along the boundary. Weak instability above 850 mb and 0-6 km bulk
shear up to 20 kts precludes widespread severe storms from
developing. Otherwise cloud cover will gradually clear behind the
wave Saturday morning with lows starting out in the upper 50s and
low 60s. Light cool advection from the north during the afternoon
keeps temps cooler than previous days in the 80s. High pressure
continues to build in through Sunday as highs gradually modify back
into the upper 80s and lower 90s for Sunday. No major changes were
made to this period.
Upper flow will become amplified with organized westerlies forecast
to remain displaced well NW of northeast Kansas. As a result...do
not expect any fronts to approach/pass through the area and any high
plains storms should remain west/northwest of the area given weak
flow.
In a nutshell, the extended looks dry for the most part and warm
with stubborn ridge expected to remain just east of the state
keeping any eastward progression of the west coast trough limited.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT)
ISSUED AT 1152 PM CDT THU AUG 27 2015
Area of showers and thunderstorms over north central KS late this
evening should move east through northeast Kansas through Friday
morning. Preferred the latest HRRR and 00Z 12KM NAM concerning
the movement of the precipitation. Given the limited instability,
precipitation will likely be showers with embedded thunderstorms
so forecasted showers at KTOP/KFOE. 00z NAM sounding for Friday
afternoon suggest surface based thunderstorms are possible as weak
boundary approaches. Kept VCTS for this possibility. Otherwise,
VFR conditions.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...67
LONG TERM...Bowen/Omitt
AVIATION...Johnson
AREA FORECAST DISCUSSION
NWS JACKSON KY
1036 PM EDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 1036 PM EDT SAT AUG 29 2015
THE FORECAST THROUGH 12Z TOMORROW HAS BEEN UPDATED. REGIONAL RADAR
IMAGERY HAS SHOWN THAT SHOWER AND STORM ACTIVITY ACROSS CENTRAL
AND EASTERN KENTUCKY HAS ENDED OVER THE PAST COUPLE OF HOURS.
RAIN SHOWERS ACROSS TENNESSEE ARE ALSO CONTINUING TO RAPIDLY
DISSIPATE. CONSIDERING THE SUN HAS LONG SINCE STOPPED ADDING
ENERGY TO THE ATMOSPHERE...AND WITH NO NEW ACTIVITY FORMING
ANYWHERE IN OR NEAR OUR AREA...AND WITH ADDED SUPPORT FROM THE
LATEST MODEL DATA OF DRY WEATHER OVERNIGHT...THE DECISION WAS MADE
TO REMOVE PRECIPITATION FROM THE FORECAST THROUGH 12Z SUNDAY.
ISOLATED SHOWERS AND STORMS SHOULD START TO FIRE AGAIN TOMORROW
MORNING ONCE THE SUN HAS BEEN UP FOR AWHILE AND THE ATMOSPHERE
BECOMES REENERGIZED. THE HAZARDOUS WEATHER OUTLOOK HAS ALSO BEEN
UPDATED TO REFLECT NO HAZARDOUS WEATHER ACROSS THE AREA TONIGHT.
SOME VALLEY IS STILL EXPECTED TO FORM...BUT SHOULD NOT CAUSE ANY
ISSUES. THE NEW FORECAST AND HWO HAVE BOTH ALREADY BEEN ISSUED.
UPDATE ISSUED AT 732 PM EDT SAT AUG 29 2015
THE FORECAST IS ON TRACK SO FAR THIS EVENING. A FEW STRAY RAIN
SHOWERS AREA AFFECTING AREAS ALONG AND NORTH OF I64 AND DOWN IN
WAYNE COUNTY. THIS MATCHES WELL WITH THE SLIGHT CHANCE POPS
CURRENTLY IN THE LATEST HOURLY FORECAST GRIDS FOR BOTH THOSE
AREAS. THESE SHOWERS WILL DIMINISH STEADILY THIS EVENING AS THE
SUN GOES DOWN. THE LATEST HOURLY OBS AND BLENDED MODEL DATA HAVE
BEEN INGESTED INTO THE GRIDS TO ESTABLISH NEW TRENDS. ASIDE FROM
THAT THE FORECAST WAS UNCHANGED. THEREFORE...NO UPDATE IS
PLANNED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 355 PM EDT SAT AUG 29 2015
19Z SFC ANALYSIS SHOWS HIGH PRESSURE EXITING TO THE EAST WHILE A
BROAD AREA OF LOW PRESSURE IS DRIFTING TOWARD THE STATE FROM THE
CENTRAL PLAINS. THE INCREASE IN MOISTURE AND LACK OF A CAP HAVE
ALLOWED A FEW CELLS TO DEVELOP THROUGH WESTERN AND NORTHERN PARTS
OF THE AREA THIS AFTERNOON. SO FAR...THE COVERAGE HAS BEEN FAIRLY
SPARSE AND THAT SHOULD BE THE CASE INTO THE EVENING AS THE
DIURNALLY DRIVEN INSTABILITY WANES. TEMPERATURES ARE IN THE MID
80S AT MOST PLACES WITH DEWPOINTS IN THE MID 60S. UNDER PARTLY
SUNNY SKIES WINDS ARE FROM THE SOUTH TO SOUTHWEST AT AROUND 10
KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A BROAD AND RATHER WEAK
TROUGH OVER THE OHIO AND TENNESSEE VALLEYS WITH SLOW MOVING
BATCHES OF ENERGY CAUGHT OVER THE REGION...STUCK BETWEEN
MARGINALLY HIGHER HEIGHTS TO THE WEST AND SOUTHEAST. GIVEN THE
BROAD AGREEMENT WITH THE MODELS HAVE FAVORED THE HIGHER RESOLUTION
GUIDANCE FROM THE HRRR AND NAM12 FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS DIMINISHING TOWARD AND AFTER SUNSET WITH PARTLY
CLOUDY SKIES ANTICIPATED THROUGH THE NIGHT. PATCHY VALLEY FOG WILL
AGAIN FORM TOWARDS DAWN WITH A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT LIKELY SETTING UP. SUNDAY WILL SEE A BETTER CHANCE FOR
CONVECTION THROUGHOUT THE CWA WITH MORE CLOUDS HELPING TO KEEP
TEMPERATURES ABOUT A CATEGORY COOLER...BUT WITH CONDITIONS EQUAL
OR EVEN MORE HUMID THAN TODAY. AGAIN PATCHY FOG AND A MINOR RIDGE
TO VALLEY TEMP SPLIT CAN BE EXPECTED LATER SUNDAY NIGHT INTO
MONDAY MORNING.
STARTED WITH THE SHORTBLEND FOR TEMPERATURES...DEWPOINTS...AND
WINDS THROUGH THE EVENING BEFORE GOING WITH THE SUPERBLEND FOR
THE REST OF THE PERIOD. DID ADJUST THE MIN TEMPERATURES EACH NIGHT
FOR TERRAIN DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE
DRIER MAV NUMBERS THROUGHOUT THE SHORT TERM PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 330 PM EDT SAT AUG 29 2015
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ACROSS MUCH OF THE EASTERN
CONUS THROUGHOUT THE EXTENDED. MEANWHILE...BOTH THE REMNANTS OF TS
ERIKA AND A WEAK UPPER LEVEL LOW OVER THE MISSISSIPPI RIVER VALLEY
WILL BE THE FEATURES THAT WILL PREVENT US FROM HAVING A COMPLETELY
DRY AND CLEAR WEEK AHEAD. THE UPPER LEVEL RIDGE WILL BE THE MAIN
PLAYER...KEEPING STABLE AIR ACROSS THE REGION DURING THE OVERNIGHT
HOURS AS THE TEMPERATURES COOL. HOWEVER...DURING THE
DAY...INCREASING TEMPERATURES AND THE ABOVE MENTIONED UPPER LEVEL
TRIGGERS WILL RESULT IN SOME ISL TO SCT SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. OUR BEST CHANCES FOR SEEING PRECIP WILL BE DURING
THE DAY MONDAY AS THE LOW THAT WAS TS ERIKA MOVES FAR ENOUGH WEST TO
IMPACT FAR SE KY. IT WILL QUICKLY TRANSITION TO THE NE
HOWEVER...WITH AN APPROACHING SHORTWAVE AND THE DIMINISHING UPPER
LEVEL LOW OVER THE MISSISSIPPI VALLEY SHIFTING EASTWARD ACROSS KY
BY MID WEEK.
MOST OF THE WINDS THROUGH THIS PERIOD WILL BE FROM THE EAST AT THE
SURFACE...AND FROM THE WSW IN THE MID AND UPPER LEVELS. IN OTHER
WORDS...IT IS NOT VERY FAVORABLE FOR SUSTAINABLE THUNDERSTORM
DEVELOPMENT. NOT GOING TO RULE OUT SOME RUMBLES OF THUNDER...SO DID
KEEP MENTION OF TSRA IN FORECAST...BUT DON/T EXPECT STORMS TO BECOME
VERY TALL OR BE FAST MOVERS. NOT TO MENTION LATEST GFS FORECAST
SOUNDINGS DON/T SHOW LI/S BELOW -5C AND CAPE ABOVE 1500 J/KG /WITH
THE EXCEPTION OF MONDAY/...SO NOTHING TOO CONCERNABLE EXPECTED
THROUGH THE WEEK AT THIS POINT.
THE OVERALL RIDGE PATTERN AND LACK OF WIDESPREAD CLOUD COVER WILL
ALLOW TEMPERATURES TO SLOWLY INCREASE EACH DAY THROUGHOUT THE WEEK.
WHILE HIGH TEMPERATURES ON MONDAY WILL STILL BE CONTAINED IN THE LOW
TO MID 80S...WE COULD SEE UPPER 80S BY TUESDAY...AND POSSIBLY EVEN A
90 DEGREE SPOT OR TWO TO ROUND OUT THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 732 PM EDT SAT AUG 29 2015
ISOLATED SHOWERS AND STORMS WILL BE AROUND THROUGH THE FIRST PART
OF THE EVENING...BUT THE TAF SITES SHOULD BE SPARED. THE NIGHT
WILL BE QUIET WITH JUST SOME LIGHT FOG ANTICIPATED IN THE
VALLEYS... POSSIBLY AFFECTING THE LOZ AND SME TAF SITES. EXPECT
MORE CLOUDS WITH A BIT LOWER CIGS DURING THE DAY ON SUNDAY...WITH
SCATTERED SHOWERS AND STORMS ANTICIPATED DURING THE AFTERNOON AND
EVENING HOURS. WINDS WILL LIGHT OVERNIGHT...AND FROM THE SOUTH TO
SOUTHWEST ON SUNDAY GENERALLY AT 5 TO 10 KTS WITH SOME HIGHER
GUSTS POSSIBLE AT SYM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
733 PM EDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 732 PM EDT SAT AUG 29 2015
THE FORECAST IS ON TRACK SO FAR THIS EVENING. A FEW STRAY RAIN
SHOWERS AREA AFFECTING AREAS ALONG AND NORTH OF I64 AND DOWN IN
WAYNE COUNTY. THIS MATCHES WELL WITH THE SLIGHT CHANCE POPS
CURRENTLY IN THE LATEST HOURLY FORECAST GRIDS FOR BOTH THOSE
AREAS. THESE SHOWERS WILL DIMINISH STEADILY THIS EVENING AS THE
SUN GOES DOWN. THE LATEST HOURLY OBS AND BLENDED MODEL DATA HAVE
BEEN INGESTED INTO THE GRIDS TO ESTABLISH NEW TRENDS. ASIDE FROM
THAT THE FORECAST WAS UNCHANGED. THEREFORE...NO UPDATE IS
PLANNED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 355 PM EDT SAT AUG 29 2015
19Z SFC ANALYSIS SHOWS HIGH PRESSURE EXITING TO THE EAST WHILE A
BROAD AREA OF LOW PRESSURE IS DRIFTING TOWARD THE STATE FROM THE
CENTRAL PLAINS. THE INCREASE IN MOISTURE AND LACK OF A CAP HAVE
ALLOWED A FEW CELLS TO DEVELOP THROUGH WESTERN AND NORTHERN PARTS
OF THE AREA THIS AFTERNOON. SO FAR...THE COVERAGE HAS BEEN FAIRLY
SPARSE AND THAT SHOULD BE THE CASE INTO THE EVENING AS THE
DIURNALLY DRIVEN INSTABILITY WANES. TEMPERATURES ARE IN THE MID
80S AT MOST PLACES WITH DEWPOINTS IN THE MID 60S. UNDER PARTLY
SUNNY SKIES WINDS ARE FROM THE SOUTH TO SOUTHWEST AT AROUND 10
KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A BROAD AND RATHER WEAK
TROUGH OVER THE OHIO AND TENNESSEE VALLEYS WITH SLOW MOVING
BATCHES OF ENERGY CAUGHT OVER THE REGION...STUCK BETWEEN
MARGINALLY HIGHER HEIGHTS TO THE WEST AND SOUTHEAST. GIVEN THE
BROAD AGREEMENT WITH THE MODELS HAVE FAVORED THE HIGHER RESOLUTION
GUIDANCE FROM THE HRRR AND NAM12 FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS DIMINISHING TOWARD AND AFTER SUNSET WITH PARTLY
CLOUDY SKIES ANTICIPATED THROUGH THE NIGHT. PATCHY VALLEY FOG WILL
AGAIN FORM TOWARDS DAWN WITH A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT LIKELY SETTING UP. SUNDAY WILL SEE A BETTER CHANCE FOR
CONVECTION THROUGHOUT THE CWA WITH MORE CLOUDS HELPING TO KEEP
TEMPERATURES ABOUT A CATEGORY COOLER...BUT WITH CONDITIONS EQUAL
OR EVEN MORE HUMID THAN TODAY. AGAIN PATCHY FOG AND A MINOR RIDGE
TO VALLEY TEMP SPLIT CAN BE EXPECTED LATER SUNDAY NIGHT INTO
MONDAY MORNING.
STARTED WITH THE SHORTBLEND FOR TEMPERATURES...DEWPOINTS...AND
WINDS THROUGH THE EVENING BEFORE GOING WITH THE SUPERBLEND FOR
THE REST OF THE PERIOD. DID ADJUST THE MIN TEMPERATURES EACH NIGHT
FOR TERRAIN DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE
DRIER MAV NUMBERS THROUGHOUT THE SHORT TERM PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 330 PM EDT SAT AUG 29 2015
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ACROSS MUCH OF THE EASTERN
CONUS THROUGHOUT THE EXTENDED. MEANWHILE...BOTH THE REMNANTS OF TS
ERIKA AND A WEAK UPPER LEVEL LOW OVER THE MISSISSIPPI RIVER VALLEY
WILL BE THE FEATURES THAT WILL PREVENT US FROM HAVING A COMPLETELY
DRY AND CLEAR WEEK AHEAD. THE UPPER LEVEL RIDGE WILL BE THE MAIN
PLAYER...KEEPING STABLE AIR ACROSS THE REGION DURING THE OVERNIGHT
HOURS AS THE TEMPERATURES COOL. HOWEVER...DURING THE
DAY...INCREASING TEMPERATURES AND THE ABOVE MENTIONED UPPER LEVEL
TRIGGERS WILL RESULT IN SOME ISL TO SCT SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. OUR BEST CHANCES FOR SEEING PRECIP WILL BE DURING
THE DAY MONDAY AS THE LOW THAT WAS TS ERIKA MOVES FAR ENOUGH WEST TO
IMPACT FAR SE KY. IT WILL QUICKLY TRANSITION TO THE NE
HOWEVER...WITH AN APPROACHING SHORTWAVE AND THE DIMINISHING UPPER
LEVEL LOW OVER THE MISSISSIPPI VALLEY SHIFTING EASTWARD ACROSS KY
BY MID WEEK.
MOST OF THE WINDS THROUGH THIS PERIOD WILL BE FROM THE EAST AT THE
SURFACE...AND FROM THE WSW IN THE MID AND UPPER LEVELS. IN OTHER
WORDS...IT IS NOT VERY FAVORABLE FOR SUSTAINABLE THUNDERSTORM
DEVELOPMENT. NOT GOING TO RULE OUT SOME RUMBLES OF THUNDER...SO DID
KEEP MENTION OF TSRA IN FORECAST...BUT DON/T EXPECT STORMS TO BECOME
VERY TALL OR BE FAST MOVERS. NOT TO MENTION LATEST GFS FORECAST
SOUNDINGS DON/T SHOW LI/S BELOW -5C AND CAPE ABOVE 1500 J/KG /WITH
THE EXCEPTION OF MONDAY/...SO NOTHING TOO CONCERNABLE EXPECTED
THROUGH THE WEEK AT THIS POINT.
THE OVERALL RIDGE PATTERN AND LACK OF WIDESPREAD CLOUD COVER WILL
ALLOW TEMPERATURES TO SLOWLY INCREASE EACH DAY THROUGHOUT THE WEEK.
WHILE HIGH TEMPERATURES ON MONDAY WILL STILL BE CONTAINED IN THE LOW
TO MID 80S...WE COULD SEE UPPER 80S BY TUESDAY...AND POSSIBLY EVEN A
90 DEGREE SPOT OR TWO TO ROUND OUT THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 732 PM EDT SAT AUG 29 2015
ISOLATED SHOWERS AND STORMS WILL BE AROUND THROUGH THE FIRST PART
OF THE EVENING...BUT THE TAF SITES SHOULD BE SPARED. THE NIGHT
WILL BE QUIET WITH JUST SOME LIGHT FOG ANTICIPATED IN THE
VALLEYS... POSSIBLY AFFECTING THE LOZ AND SME TAF SITES. EXPECT
MORE CLOUDS WITH A BIT LOWER CIGS DURING THE DAY ON SUNDAY...WITH
SCATTERED SHOWERS AND STORMS ANTICIPATED DURING THE AFTERNOON AND
EVENING HOURS. WINDS WILL LIGHT OVERNIGHT...AND FROM THE SOUTH TO
SOUTHWEST ON SUNDAY GENERALLY AT 5 TO 10 KTS WITH SOME HIGHER
GUSTS POSSIBLE AT SYM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AR
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...AR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT FRI AUG 28 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 411 PM EDT FRI AUG 28 2015
WV IMAGERY AND RAP ANALYSIS INDICATED MAINLY ZONAL MID/UPPER LEVEL
FLOW ALONG THE US/CANADIAN BORDER. A SHORTWAVE TROUGH FROM NW
ONTARIO INTO NRN MN SUPPORTED SCT SHRA/TSRA OVER THE MN ARROWHEAD
INTO NRN ONTARIO WEST OF THUNDER BAY. TO THE SOUTH...ANOTHER SHRTWV
OVER IA BRINGING SHOWERS FROM NE IA THROUGH SW WI WAS SLOWLY LIFTING
TO THE ENE. THE LEADING EDGE OF THE PCPN TO NEAR AUW.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES PREVAILED ACROSS UPPER MI
WITH TEMPS IN THE MID 70S.
TONIGHT...MOST OF THE CWA WILL REMAIN BETWEEN THE INFLUENCE OF THE
NRN AND SRN STREAM SHORTWAVES. RADAR TRENDS AND SHORT RANGE MODELS
SUGGEST THAT THE RAIN OVER WI TO AFFECT MAINLY THE SRN TIER ALONG
AND SOUTH OF US-2 FROM IMT EASTWARD. SHRA/TSRA WITH THE NRN STREAM
SHRTWV MAY BRUSH MAINLY THE KEWEENAW BY LATE THIS EVENING AND
POSSIBLY INTO THE NRN PORTION OF UPPER MI. FCST MUCAPE VALUES INTO
THE 500-1000 J/KG RANGE OVER THE NORTH COULD ALSO SUPPORT ISOLD
TSRA.
SATURDAY...SOME SHOWERS MAY LINGER OVER THE SE PORTION OF THE CWA
ASSOCIATED WITH REMNANTS OF THE WI SHRTWV OR POSSIBLY AIDED BY A
TRAILING SHRTWV DIVING INTO NRN WI. HOWEVER...EXPECT THE PCPN TO
SLIDE OFF TO THE EAST BY AFTERNOON. WITH SOME CLEARING INTO THE WEST
HALF BY AFTERNOON...TEMPS WILL REBOUND INTO THE MID AND UPPER 70.
GREATER CLOUD COVER OVER THE EAST AND WITH SRLY FLOW OFF OF LAKE
MI...TEMPS WILL REMAIN IN UPPER 60S AND LOWER 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM EDT FRI AUG 28 2015
COULD SEE A FEW SHOWERS IN THE FIRST 6 HOURS OF THE FORECAST SAT
NIGHT...BUT THINK VAST MAJORITY OF PRECIP ASSOCIATED WITH A
SHORTWAVE WILL BE OUT OF THE AREA. OTHERWISE...PRECIP CHANCES ARE
LOW IN THE LONG TERM AS A MID-UPPER RIDGE MOVES IN AND SITS OVER THE
CENTRAL TO ERN CONUS. COULD SEE SOME PRECIP MID-LATE NEXT WEEK AS
SHORTWAVES TRY TO TOP THE RIDGE...BUT PREDICTABILITY IS TOO LOW TO
JUSTIFY ANYTHING ABOVE SLIGHT CHANCE POPS.
TEMPS WILL BE ON THE INCREASE AND WILL ALREADY BE ABOVE NORMAL SUN.
HIGHS SUN WILL BE IN THE MID 70S TO LOW 80S AS 850MB TEMPS START OUT
IN THE MID TEENS C. 850MB TEMPS THROUGH THE REST OF THE WEEK WILL BE
AROUND 20C...RESULTING IN HIGH TEMPS 10 OR MORE DEGREES ABOVE
NORMAL.
COULD SEE SOME PATCHY FOG AROUND SAT NIGHT INTO EARLY SUN MORNING
AND AGAIN SUN NIGHT INTO MON MORNING AS HIGH PRESSURE/SUBSIDENCE
MOVES IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 141 PM EDT FRI AUG 28 2015
MVFR CIGS AT CMX ARE EXPECTED TO GIVE WAY TO VFR CONDITIONS BY LATE
THIS AFTERNOON. THERE IS ALSO SLIGHT CHANCE FOR SHOWERS AT CMX...BUT
PROB IS TOO LOW TO INCLUDE IN THE TAF. OTHERWISE...VFR CONDITIONS
WILL CONTINUE THROUGH THIS FCST PERIOD AT KIWD/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT FRI AUG 28 2015
EXPECT A PERIOD OF MODERATE SW WINDS LATE TONIGHT INTO EARLY GUSTING
TO 15-20 KNOTS. OTHERWISE...A GENERALLY WEAK PRES GRADIENT WILL
DOMINATE THE UPPER LAKES INTO EARLY NEXT WEEK. ON MOST DAYS...WINDS
WILL BE UNDER 15KT. LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE
WEEKEND WITH HIGH PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
207 AM EDT FRI AUG 28 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 411 PM EDT THU AUG 27 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW WNW FLOW INTO THE UPPER
GREAT LAKES. RIDGE THAT EXTENDED FROM THE SRN ROCKIES TO SCNTRL
CANADA YESTERDAY IS WEAKENING DUE TO SHORTWAVE ENERGY TRACKING FROM
NRN ALBERTA TO NRN MANITOBA AND ANOTHER SHORTWAVE MOVING FROM WY
INTO THE WRN PLAINS. THAT SHORTWAVE WILL BEGIN TO BECOME A FCST
ISSUE HERE ON FRI. AFTER MORNING FOG...THE DAY HAS TURNED MOSTLY
SUNNY...THOUGH AN ELEVATED SMOKE LAYER HAS LEFT THE SKY WITH A HAZY
APPEARANCE. TEMPS HAVE REBOUNDED INTO THE MID 60S TO LWR 70S.
QUIET WEATHER WILL CONTINUE TONIGHT AS DRY AIR IN A RELATIVE SENSE
DOMINATES MOST OF THE COLUMN. LIGHT SOUTHERLY WINDS AND AN INCREASE
IN PRECIPITABLE WATER WILL RESULT IN A WARMER NIGHT THAN LAST NIGHT.
EXPECT MINS MOSTLY IN THE 50S...THOUGH DOWNSLOPE AREAS NEAR LAKE
SUPERIOR MAY NOT FALL BLO 60F.
ON FRI...THE WRN PLAINS SHORTWAVE WILL MOVE TO WI. BEST
WAA/ISENTROPIC ASCENT ASSOCIATED WITH FEATURE SHIFTS FROM NRN IA/SRN
MN INTO WI...SO BULK OF PCPN WILL PASS BY TO THE S OF HERE. THAT
AREA IS ALSO WHERE MODELS SHOW HEAVIEST PCPN. PCPN CHANCES WILL BE
MUCH MORE LIMITED TO THE N. WHILE HIGH RES WRF-ARW/NMM ARE LIKELY
TOO AGGRESSIVE IN SPREADING PCPN INTO SCNTRL UPPER MI FRI...MOST
MODELS DO BRING SOME PCPN INTO THE SCNTRL IN THE AFTN. WILL PAINT
CHC POPS OVER THE FAR SCNTRL. DEPENDING ON CLOUD COVER/DAYTIME
HEATING...THE GFS AND ESPECIALLY NAM BUILD A LITTLE BIT OF
INSTABILITY PER MLCAPES FARTHER N. HAVE INCLUDED SCHC POPS FOR -SHRA
IN THE EVENT A FEW -SHRA MANAGE TO POP IN THE AFTN.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 301 PM EDT THU AUG 27 2015
PLENTY OF UNCERTAINTY IN THE FIRST 24 HOURS OF THE LONG TERM...FRI
NIGHT AND SAT. A SHORTWAVE IS SET TO MOVE OUT OF THE CENTRAL PLAINS
AND MOVE THROUGH OR NEAR THE REGION DURING THIS TIME. THE 00Z/27
ECMWF IS DEEPEST AND FARTHEST NORTH WITH THE SHORTWAVE...WITH RAIN
OVER MOST OF THE CWA. THE 12Z/27 GFS IS QUITE A BIT WEAKER AND
FARTHER S...KEEPING MOST OF THE CWA DRY. THE 12Z/27 GEM AND 12Z/27
NAM MATCH CLOSER TO THE GFS...BUT DO BRING SOME PRECIP INTO THE SRN
CWA. WILL TEND TO FAVOR A GFS/NAM/GEM CONSENSUS GIVEN HOW MUCH OF AN
OUTLIER THE ECMWF IS. THIS RESULTS IN CHANCE POPS OVER SCENTRAL UPPER
MI FRI NIGHT AND SAT MORNING AND SLIGHT CHANCE POPS ELSEWHERE. DRY
CONDITIONS EXPECTED BY 00Z SUN.
MODELS CONTINUE TO BUILD AN UPPER RIDGE OVER THE REGION FROM SUN
THROUGH THE REST OF NEXT WEEK. RAIN CHANCES WILL BE MINIMAL...BUT
COULD SEE SOME CONVECTION WED OR THU IF SHORTWAVE ENERGY CAN ROUND
THE TOP OF THE RIDGE...BUT CHANCES ARE LOW. THE AIRMASS WILL BE ON
THE RISE...HOVERING AROUND 20C FROM LATE MON THROUGH THE REST OF THE
WEEK. THIS RESULTS IN TEMPS BEING 10 OR MORE DEGREES ABOVE NORMAL
FROM MON ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 207 AM EDT FRI AUG 28 2015
RELATIVELY DRY AIR MASS OVER THE AREA SHOULD ENSURE VFR CONDITIONS
CONTINUE THRU THIS FCST PERIOD AT KIWD/KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT THU AUG 27 2015
A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER LAKES INTO
EARLY NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT...BUT THERE
WILL BE SOME PERIODS WHERE GUSTS WILL GET INTO THE 15-20KT RANGE.
LOOKS LIKE THE LIGHTEST WINDS WILL OCCUR OVER THE WEEKEND WITH HIGH
PRES RIDGE MORE FIRMLY IN CONTROL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
523 PM CDT FRI AUG 28 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 315 PM CDT FRI AUG 28 2015
WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY
EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST
THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH
HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN
MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE
WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW
LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE
AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY
LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING
FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM
REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL.
MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS
AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS.
BRITT
.LONG TERM: (SATURDAY THROUGH NEXT FRIDAY)
ISSUED AT 316 PM CDT FRI AUG 28 2015
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ON
SATURDAY AND SATURDAY EVENING AS AN UPPER LEVEL TROUGH MOVES
SLOWLY SOUTHEASTWARD THROUGH OUR AREA. IT NOW APPEARS THAT THE
COLD FRONT WILL ONLY MAKE IT INTO NORTHEAST MO AND WEST CENTRAL IL
BEFORE GRADUALLY DISSIPATING. ONLY SLIGHT COOLING IS EXPECTED
ACROSS NORTHEAST MO AND WEST CENTRAL IL SATURDAY AND SATURDAY
NIGHT WITH THE REST OF THE AREA SLIGHTLY WARMER AND MORE HUMID
DESPITE THE CLOUD COVER ON SATURDAY WITH MAINLY A WEAK SOUTHERLY
FLOW. ALTHOUGH THE CHANCE OF PRECIPITATION WILL LESSEN BY LATE
SATURDAY NIGHT AND SUNDAY...THERE MAY STILL BE AT LEAST ISOLATED
SHOWERS/STORMS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL AS THE
WEAKENING UPPER LEVEL TROUGH...SHEAR AXIS MOVES ONLY SLOWLY
SOUTHEASTWARD. A WAMER PERIOD OF WEATHER IS FORECAST FOR THE NEXT
WORK WEEK DUE TO PERSISTENT SOUTHERLY SURFACE/LOW LEVEL FLOW WITH
THE SURFACE/850 MB RIDGE EAST/SOUTHEAST OF OUR AREA...AND AT
LEAST UPPER LEVEL RIDGING ACROSS NORTHWEST MO. WILL KEEP THE
REMAINDER OF THE FORECAST DRY FOR NOW...ALTHOUGH COULD NOT RULE
OUT A FEW SHOWERS/STORMS MAINLY DURING THE AFTERNOON AND EARLY
EVENING HOURS AS THE MODELS CONTINUE TO DEPICT SOME WEAK MID-UPPER
LEVEL TROUGHING...SHEAR AXIS ACROSS MAINLY SOUTHEAST MO AND
SOUTHWEST IL.
GKS
&&
.AVIATION: (FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 519 PM CDT FRI AUG 28 2015
SLOW MOVING TROF OF LOW PRESSURE AND SEVERAL UPPER AIR
DISTURBANCES WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO THE
REGION TONIGHT THROUGH SATURDAY NIGHT. EXPECT VFR CONDITIONS
OUTSIDE OF ANY HEAVIER SHOWERS THAT COULD TEMPORARILY REDUCE
THE VISIBILITY AND CEILING AT A TERMINAL. LIGHT SOUTHEAST/SOUTH
WIND EXPECTED TO CONTINUE THROUGH THE PERIOD.
SPECIFICS FOR KSTL:
SCATTERED SHOWERS SHOULD ARRIVE NEAR THE TERMINAL COMPLEX AROUND
12Z WITH THE THREAT OF SCATTERED THUNDERSTORMS DEVELOPING DURING
THE HEAT OF THE DAY...OR AFTERNOON. CONFIDENCE IN COVERAGE OF RAIN
IS NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST OUTSIDE OF VICINITY
AT THIS TIME. LIGHT SOUTHEAST TO SOUTH WIND EXPECTED TO CONTINUE
THROUGH THE PERIOD.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
409 PM CDT FRI AUG 28 2015
.DISCUSSION...
Issued at 409 PM CDT FRI AUG 28 2015
Tonight...
Positive tilted shortwave trough as noted in satellite imagery from
IA through KS will slide east tonight. Scattered convection will
form along an associated cold front within a moderately
unstable airmass....at least it will be into the early evening
hours.
A narrow band of convection has finally formed over east
central KS where MLCAPES between 1500-2000J/kg are noted. Further
northeast VFR ceilings within the warm sector have pretty much
capped intense convection as radar shows sputtering area of low
topped showers. The east central KS activity may be the only region
which develops deep convection, albeit the non-severe variety. Will
hit PoPs highest over northern and west central counties until a few
hours after sunset. Thereafter expect a fairly quick drop off in
intensity and coverage as instability hits the skids. Believe the
trend of the HRRR and 12z NAM looks reasonable. QPF will also be
muted. Could see isolated showers form after the passage of the
frontal convection and last into the pre-dawn hours.
Saturday - Sunday...
The above shortwave is expected to flounder over the Mid MO Valley
over the weekend. The h7 shortwave trough will be slow to exit the
CWA resulting in a general region of uvv over the eastern 1/2 of the
CWA. Thinking there will be sufficient breaks in the overcast such
that isolated instability showers/storms will be possible Saturday
afternoon over parts of northeast and central MO. Current
temperature forecast may be a bit too optimistic should the
afternoon clouds fail to break up.
Sunday looks dry with a slight warm-up as the mid level trough
washes out.
Monday - Friday...
The operational models transition to a broadening southwesterly flow
pattern after the upper level ridge axis leans over into the Central
Plains. This will allow warmer more seasonal temperatures and
humidity back into the region. While the h7 temperatures don`t get
overly hot and cap off the environment a lack of any discernible
mid/upper level wave or surface boundaries will greatly limit the
rain chances. As such will go with a dry forecast until some feature
of significance is picked up by the models.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1253 PM CDT FRI AUG 28 2015
Isolated light afternoon showers east of I-35. VFR conditions through
the afternoon hours. Otherwise, scattered convection expected to form
by late afternoon over northwest MO and northeast KS along or just
ahead of a cold front. Activity expected to advance southeast through
the early evening hours but weaken after sunset. Except for a brief
period of MVFR ceilings with the strongest storms over northwest MO
expect VFR ceilings. Timing remains too uncertain for a 2hr TEMPO
group for the Kansas City terminals.
Should see MVFR ceilings follow with the passage of the cold front.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
344 PM CDT FRI AUG 28 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 315 PM CDT FRI AUG 28 2015
WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY
EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST
THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH
HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN
MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE
WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW
LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE
AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY
LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING
FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM
REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL.
MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS
AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS.
BRITT
.LONG TERM: (SATURDAY THROUGH NEXT FRIDAY)
ISSUED AT 316 PM CDT FRI AUG 28 2015
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED ON
SATURDAY AND SATURDAY EVENING AS AN UPPER LEVEL TROUGH MOVES
SLOWLY SOUTHEASTWARD THROUGH OUR AREA. IT NOW APPEARS THAT THE
COLD FRONT WILL ONLY MAKE IT INTO NORTHEAST MO AND WEST CENTRAL IL
BEFORE GRADUALLY DISSIPATING. ONLY SLIGHT COOLING IS EXPECTED
ACROSS NORTHEAST MO AND WEST CENTRAL IL SATURDAY AND SATURDAY
NIGHT WITH THE REST OF THE AREA SLIGHTLY WARMER AND MORE HUMID
DESPITE THE CLOUD COVER ON SATURDAY WITH MAINLY A WEAK SOUTHERLY
FLOW. ALTHOUGH THE CHANCE OF PRECIPITATION WILL LESSEN BY LATE
SATURDAY NIGHT AND SUNDAY...THERE MAY STILL BE AT LEAST ISOLATED
SHOWERS/STORMS ACROSS MAINLY SOUTHEAST MO AND SOUTHWEST IL AS THE
WEAKENING UPPER LEVEL TROUGH...SHEAR AXIS MOVES ONLY SLOWLY
SOUTHEASTWARD. A WAMER PERIOD OF WEATHER IS FORECAST FOR THE NEXT
WORK WEEK DUE TO PERSISTENT SOUTHERLY SURFACE/LOW LEVEL FLOW WITH
THE SURFACE/850 MB RIDGE EAST/SOUTHEAST OF OUR AREA...AND AT
LEAST UPPER LEVEL RIDGING ACROSS NORTHWEST MO. WILL KEEP THE
REMAINDER OF THE FORECAST DRY FOR NOW...ALTHOUGH COULD NOT RULE
OUT A FEW SHOWERS/STORMS MAINLY DURING THE AFTERNOON AND EARLY
EVENING HOURS AS THE MODELS CONTINUE TO DEPICT SOME WEAK MID-UPPER
LEVEL TROUGHING...SHEAR AXIS ACROSS MAINLY SOUTHEAST MO AND
SOUTHWEST IL.
GKS
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM CDT FRI AUG 28 2015
EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH THIS EVENING. THEN
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS
CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS OVERNIGHT
THAT WILL EVENTUALLY SPREAD INTO THE ST. LOUIS METRO AREA ON
SATURDAY MORNING. SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP
ON SATURDAY AFTERNOON AROUND THE ST. LOUIS METRO TAF SITES.
SPECIFICS FOR KSTL: EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH
TONIGHT. THEN SCATTERED SHOWERS WILL MOVE INTO THE AREA BY LATE
SATURDAY MORNING WITH AN INCREASING CHANCE OF SCATTERED
THUNDERSTORMS AS AN UPPER LEVEL STORM SYSTEM MOVES INTO THE AREA
BY LATE SATURDAY AFTERNOON.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
316 PM CDT FRI AUG 28 2015
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 315 PM CDT FRI AUG 28 2015
WATER VAPOR IMAGERY SHOWS THAT A SHORTWAVE TROUGH IS MOVING SLOWLY
EAST ACROSS MISSOURI AT THIS HOUR. LATEST RUNS OF THE RAP SUGGEST
THAT IT WILL TAKE ALL EVENING FOR THIS FIRST SHORTWAVE TO REACH
HALFWAY ACROSS THE CWA WHILE A SECOND SHORTWAVE WILL ENTER WESTERN
MISSOURI BEHIND IT LATER TONIGHT. LOW LEVEL MOISTURE CONVERGENCE
WILL INCREASE ACROSS EASTERN MISSOURI BY LATER THIS EVENING AS LOW
LEVEL JET VEERS AND INCREASES IN SPEED SLIGHTLY. THIS SHOULD CAUSE
AN INCREASE IN COVERAGE IN SCATTERED SHOWERS AND THUNDERSTORMS BY
LATE EVENING AND OVERNIGHT OVER THE REGION BECAUSE OF THE FORCING
FROM THE SHORTWAVES AND THE MOISTURE CONVERGENCE. THE 1KM
REFLECTIVITY FROM THE CAMS DEPICTS THIS PRETTY WELL.
MOS LOWS TONIGHT LOOK REASONABLE GIVEN THE INCREASING DEWPOINTS
AHEAD OF THE COLD FRONT CURRENTLY OVER THE CENTRAL PLAINS.
BRITT
.LONG TERM: (TONIGHT THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI AUG 28 2015
THERE IS GOOD AGREEMENT IN THE 00Z GUIDANCE THAT FRONTAL
BOUNDARY AND ASSOCIATED SHORTWAVE SHOULD ALLOW THUNDERSTORMS
THREAT TO SLOWLY EXPAND OVER THE NORTHWEST HALF OF THE CWA
TONIGHT...WITH THE STL METRO LIKELY ON THE EASTERN EDGE OF THE
THREAT DURING THE PREDAWN HOURS. DUE TO PROGGED LOW LEVEL
FORCING AHEAD OF THE FRONT, HAVE UPPED POPS INTO LIKELY CATEGORY
OVER OUR EXTREME NORTHWEST COUNTIES.
HOWEVER...FROM SATURDAY MORNING ON FEATURES AND MODEL SPECIFICS
BEGIN TO DIVERGE AND BECOME INCREASING NEBULOUS. WHILE MODELS DO
AGREE THAT NORTHERN PORTION OF THE SHORTWAVE WILL CONTINUE TO PRESS
INTO THE LOWER GREAT LAKES DURING THE DAY...THEY DISAGREE WITH THEIR
HANDLING OF THE SOUTHERN PORTION OF THE SHORTWAVE ENERGY AS IT
STRETCHES SOUTHEAST AND POSSIBLY MERGING WITH ANOTHER WEAK
CIRCULATION ALONG THE GULF COAST (WHICH APPEARS TO ORIGINATE WITH
A BIT OF ENERGY THAT BREAKS OFF FROM THE BASE OF THE CURRENT EAST
COAST TROF). GFS AND NAM SUGGEST SOME TYPE OF REMNANT CIRCULATION
TAKING UP RESIDENCE IN THE VICINITY OF SW MO BY SUNDAY WITH
RESIDUAL SURFACE FRONT BECOMING STATIONARY OVER THE AREA...WHILE
ECMWF WANTS TO PUSH THE INCREASINGLY WEAK SHORTWAVE ENERGY AND
SURFACE BOUNDARY SOUTH WITH TIME.
IF NAM AND GFS SOLUTIONS DO COME TO FRUITION ON SUNDAY...AND IF NAM
LOW LEVEL MOISTURE FORECAST (WHICH IS OFTEN TOO HIGH) ALSO
VERIFIES...THEN THE DRY FORECAST ON SUNDAY WILL BE IN JEOPARDY.
HOWEVER...WOULD LIKE TO SEE ADDITIONAL SUPPORT FOR THESE WEAK
FEATURES AND TRENDS BEFORE REINTRODUCING CONVECTION ON SUNDAY. SO
FOR NOW HAVE CONTINUED TO TREND THE FORECAST TO THE ECMWF
SOLUTION...NAMELY THUNDERSTORM CHANCES EXPANDING SOUTHEAST ACROSS
THE CWA DURING THE DAY ON SATURDAY THEN GRADUALLY DIMINISHING FROM
NW TO SE LATE SATURDAY AFTERNOON AND SATURDAY NIGHT.
DESPITE THE DISCREPANCY IN THE UA PROGS ON SUNDAY...MEDIUM RANGE
SOLUTIONS REMAIN IN GOOD RUN TO RUN AND MODEL TO MODEL AGREEMENT
THAT WESTERN RIDGE WILL BE EXPANDING EAST INTO THE MID
MISSISSIPPI AND OHIO VALLEYS DURING THE UPCOMING WEEK. THIS SHOULD
MEAN DRY WEATHER FOR THE FA...ALONG WITH TEMPERATURES REBOUNDING
TO LATE SUMMER LEVELS WITH HIGHS IN THE UPPER 80S-LOWER 90S.
TRUETT
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM CDT FRI AUG 28 2015
EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH THIS EVENING. THEN
EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS
CENTRAL AND NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS OVERNIGHT
THAT WILL EVENTUALLY SPREAD INTO THE ST. LOUIS METRO AREA ON
SATURDAY MORNING. SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP
ON SATURDAY AFTERNOON AROUND THE ST. LOUIS METRO TAF SITES.
SPECIFICS FOR KSTL: EXPECT MAINLY DRY AND VFR CONDITIONS THROUGH
TONIGHT. THEN SCATTERED SHOWERS WILL MOVE INTO THE AREA BY LATE
SATURDAY MORNING WITH AN INCREASING CHANCE OF SCATTERED
THUNDERSTORMS AS AN UPPER LEVEL STORM SYSTEM MOVES INTO THE AREA
BY LATE SATURDAY AFTERNOON.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1238 PM CDT FRI AUG 28 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 305 AM CDT FRI AUG 28 2015
PCPN CHANCES TODAY AND THEN TEMPERATURES THE NEXT FEW DAYS WILL BE
THE MAIN FORECAST CONCERNS.
FAIRLY WIDESPREAD AREA OF SHRA AND TSRA WILL CONTINUE TO MOVE EAST
THIS MORNING...ASSOCIATED WITH SHORTWAVE TROUGH MOVING THROUGH THE
REGION. WATER VAPOR SATELLITE IMAGERY LOOP IN COMBINATION WITH
RECENT 500 MB RUC MODEL INITIALIZATIONS SHOWED A FAIRLY STRONG
WAVE FOR THIS TIME OF YEAR. 12 HOUR HEIGHT FALLS AT 500 MB WERE UP
TO ABOUT 50 METERS. ATMOSPHERE WAS ALSO QUITE MOIST. 700 MB
DEWPOINTS OF 4-8 DEGREES C WERE NOTED FROM THE DESERT SW UP INTO
WRN KS AND SWRN NE AT 00Z LAST EVENING...AND FORECAST SOUNDINGS
SUGGEST PW VALUES ARE AROUND 2 INCHES OR MORE EARLY THIS MORNING.
ALTHOUGH THE STRONGEST AREA OF LIFT AND HIGHEST MOISTURE WILL BE
SHIFTING EAST OF THE LOCAL AREA...KEPT SOME POPS GOING MUCH OF THE
DAY. A WEAKER AREA OF LIFT SHOULD SPREAD SEWD OVER THE REGION AND
FORECAST SOUNDINGS STILL SHOW SOME INSTABILITY. WILL KEEP RAIN
CHANCES MAINLY AT 20-30 PERCENT AFTER EARLY MORNING ACTIVITY ENDS.
RECENT HRRR RUNS AND EVEN THE 00Z NAM SUGGEST PREVIOUS SCENARIO...
WITH AT LEAST ISOLD SHRA/TSRA POSSIBLE.
LINGERED A SLIGHT CHANCE OF TSRA IN OUR FAR SERN ZONES EARLY THIS
EVENING...THEN IT SHOULD BE MAINLY DRY THROUGH SUNDAY. KEPT SOME
MENTION OF FOG TONIGHT WITH LIGHT WINDS AND BOTH GFS MOS AND NAM
MOS SUGGESTING AT LEAST PATCHY FOG LATE TONIGHT INTO SAT MORNING.
DID NOT MENTION FOG SATURDAY NIGHT...BUT SFC RIDGE AXIS WILL BE
CLOSE TO THE AREA AND WILL NEED TO MONITOR. RETURN FLOW WITH S/SE
SFC WINDS SHOULD THEN STRENGTHEN SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 305 AM CDT FRI AUG 28 2015
MID LEVEL RIDGE EXTENDING FROM NWRN MEXICO UP INTO THE CNTRL
PLAINS AND A TROUGH FROM WRN CANADA INTO THE NWRN UNITED STATES
WILL BE THE MAIN FEATURES AT THE START OF THIS PERIOD. RIDGE WILL
SLIDE SLOWLY SEWD AS THE TROUGH TO THE NORTHWEST DIGS. WEAK RIPPLES
MOVING NEWD THROUGH THE REGION COULD BRING SOME TSRA...WITH BEST
CHANCES BEING TUE NIGHT AND AGAIN THU NIGHT.
TEMPERATURES SHOULD BE AT OR ABOVE NORMAL OVER THE AREA FOR MOST
OR ALL OF NEXT WEEK.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1230 PM CDT FRI AUG 28 2015
CEILINGS HAD TRENDED TO MVFR AT ALL THREE TAF SITES AS OF 17Z.
THOUGH SOME PATCHY IFR CIGS LINGER NORTH OF KOFK IN SOUTH
DAKOTA...LIFTING AND THINNING OF CIGS SHOULD CONTINUE THROUGH 00Z.
THEN AS HIGH PRESSURE SETTLES IN ACROSS THE REGION
OVERNIGHT...WINDS WILL GO LIGHT AND COMBINED WITH RECENT RAIN AND
SURFACE MOISTURE EXPECT IFR VISIBILITIES AND CIGS TO SET IN AFTER
10Z AT ALL THREE TAF SITES. AFTER 16Z CONDITIONS WILL IMPROVE TO
MVFR TO VFR.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
701 AM CDT FRI AUG 28 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 305 AM CDT FRI AUG 28 2015
PCPN CHANCES TODAY AND THEN TEMPERATURES THE NEXT FEW DAYS WILL BE
THE MAIN FORECAST CONCERNS.
FAIRLY WIDESPREAD AREA OF SHRA AND TSRA WILL CONTINUE TO MOVE EAST
THIS MORNING...ASSOCIATED WITH SHORTWAVE TROUGH MOVING THROUGH THE
REGION. WATER VAPOR SATELLITE IMAGERY LOOP IN COMBINATION WITH
RECENT 500 MB RUC MODEL INITIALIZATIONS SHOWED A FAIRLY STRONG
WAVE FOR THIS TIME OF YEAR. 12 HOUR HEIGHT FALLS AT 500 MB WERE UP
TO ABOUT 50 METERS. ATMOSPHERE WAS ALSO QUITE MOIST. 700 MB
DEWPOINTS OF 4-8 DEGREES C WERE NOTED FROM THE DESERT SW UP INTO
WRN KS AND SWRN NE AT 00Z LAST EVENING...AND FORECAST SOUNDINGS
SUGGEST PW VALUES ARE AROUND 2 INCHES OR MORE EARLY THIS MORNING.
ALTHOUGH THE STRONGEST AREA OF LIFT AND HIGHEST MOISTURE WILL BE
SHIFTING EAST OF THE LOCAL AREA...KEPT SOME POPS GOING MUCH OF THE
DAY. A WEAKER AREA OF LIFT SHOULD SPREAD SEWD OVER THE REGION AND
FORECAST SOUNDINGS STILL SHOW SOME INSTABILITY. WILL KEEP RAIN
CHANCES MAINLY AT 20-30 PERCENT AFTER EARLY MORNING ACTIVITY ENDS.
RECENT HRRR RUNS AND EVEN THE 00Z NAM SUGGEST PREVIOUS SCENARIO...
WITH AT LEAST ISOLD SHRA/TSRA POSSIBLE.
LINGERED A SLIGHT CHANCE OF TSRA IN OUR FAR SERN ZONES EARLY THIS
EVENING...THEN IT SHOULD BE MAINLY DRY THROUGH SUNDAY. KEPT SOME
MENTION OF FOG TONIGHT WITH LIGHT WINDS AND BOTH GFS MOS AND NAM
MOS SUGGESTING AT LEAST PATCHY FOG LATE TONIGHT INTO SAT MORNING.
DID NOT MENTION FOG SATURDAY NIGHT...BUT SFC RIDGE AXIS WILL BE
CLOSE TO THE AREA AND WILL NEED TO MONITOR. RETURN FLOW WITH S/SE
SFC WINDS SHOULD THEN STRENGTHEN SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 305 AM CDT FRI AUG 28 2015
MID LEVEL RIDGE EXTENDING FROM NWRN MEXICO UP INTO THE CNTRL
PLAINS AND A TROUGH FROM WRN CANADA INTO THE NWRN UNITED STATES
WILL BE THE MAIN FEATURES AT THE START OF THIS PERIOD. RIDGE WILL
SLIDE SLOWLY SEWD AS THE TROUGH TO THE NORTHWEST DIGS. WEAK RIPPLES
MOVING NEWD THROUGH THE REGION COULD BRING SOME TSRA...WITH BEST
CHANCES BEING TUE NIGHT AND AGAIN THU NIGHT.
TEMPERATURES SHOULD BE AT OR ABOVE NORMAL OVER THE AREA FOR MOST
OR ALL OF NEXT WEEK.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 656 AM CDT FRI AUG 28 2015
VARIABLE CONDITIONS EXPECTED DURING THE PERIOD. IFR CIGS LOCATED
UNDER UPPER LOW OVER NORTHEAST NEBRASKA AND BEHIND COLD FRONT INTO
SOUTH CENTRAL NEBRASKA. LOWER CIGS SHOULD SPREAD EAST BEHIND FRONT
THROUGH 18Z WITH CIGS IMPROVING TO MVFR THROUGH 00Z. VFR
CONDITIONS THEN DEVELOP AFTER 00Z BUT A PERIOD OF LIFR CIGS AND
VSBY POSSIBLE AFTER 09Z AT ALL THREE SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
305 AM CDT FRI AUG 28 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 305 AM CDT FRI AUG 28 2015
PCPN CHANCES TODAY AND THEN TEMPERATURES THE NEXT FEW DAYS WILL BE
THE MAIN FORECAST CONCERNS.
FAIRLY WIDESPREAD AREA OF SHRA AND TSRA WILL CONTINUE TO MOVE EAST
THIS MORNING...ASSOCIATED WITH SHORTWAVE TROUGH MOVING THROUGH THE
REGION. WATER VAPOR SATELLITE IMAGERY LOOP IN COMBINATION WITH
RECENT 500 MB RUC MODEL INITIALIZATIONS SHOWED A FAIRLY STRONG
WAVE FOR THIS TIME OF YEAR. 12 HOUR HEIGHT FALLS AT 500 MB WERE UP
TO ABOUT 50 METERS. ATMOSPHERE WAS ALSO QUITE MOIST. 700 MB
DEWPOINTS OF 4-8 DEGREES C WERE NOTED FROM THE DESERT SW UP INTO
WRN KS AND SWRN NE AT 00Z LAST EVENING...AND FORECAST SOUNDINGS
SUGGEST PW VALUES ARE AROUND 2 INCHES OR MORE EARLY THIS MORNING.
ALTHOUGH THE STRONGEST AREA OF LIFT AND HIGHEST MOISTURE WILL BE
SHIFTING EAST OF THE LOCAL AREA...KEPT SOME POPS GOING MUCH OF THE
DAY. A WEAKER AREA OF LIFT SHOULD SPREAD SEWD OVER THE REGION AND
FORECAST SOUNDINGS STILL SHOW SOME INSTABILITY. WILL KEEP RAIN
CHANCES MAINLY AT 20-30 PERCENT AFTER EARLY MORNING ACTIVITY ENDS.
RECENT HRRR RUNS AND EVEN THE 00Z NAM SUGGEST PREVIOUS SCENARIO...
WITH AT LEAST ISOLD SHRA/TSRA POSSIBLE.
LINGERED A SLIGHT CHANCE OF TSRA IN OUR FAR SERN ZONES EARLY THIS
EVENING...THEN IT SHOULD BE MAINLY DRY THROUGH SUNDAY. KEPT SOME
MENTION OF FOG TONIGHT WITH LIGHT WINDS AND BOTH GFS MOS AND NAM
MOS SUGGESTING AT LEAST PATCHY FOG LATE TONIGHT INTO SAT MORNING.
DID NOT MENTION FOG SATURDAY NIGHT...BUT SFC RIDGE AXIS WILL BE
CLOSE TO THE AREA AND WILL NEED TO MONITOR. RETURN FLOW WITH S/SE
SFC WINDS SHOULD THEN STRENGTHEN SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 305 AM CDT FRI AUG 28 2015
MID LEVEL RIDGE EXTENDING FROM NWRN MEXICO UP INTO THE CNTRL
PLAINS AND A TROUGH FROM WRN CANADA INTO THE NWRN UNITED STATES
WILL BE THE MAIN FEATURES AT THE START OF THIS PERIOD. RIDGE WILL
SLIDE SLOWLY SEWD AS THE TROUGH TO THE NORTHWEST DIGS. WEAK RIPPLES
MOVING NEWD THROUGH THE REGION COULD BRING SOME TSRA...WITH BEST
CHANCES BEING TUE NIGHT AND AGAIN THU NIGHT.
TEMPERATURES SHOULD BE AT OR ABOVE NORMAL OVER THE AREA FOR MOST
OR ALL OF NEXT WEEK.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1127 PM CDT THU AUG 27 2015
RADAR MOSAIC TREND THE LAST FEW HOURS REVEALING THAT AREAL COVERAGE
INCREASE MAINLY OVER NERN AND EAST-CENTRAL NEB THIS MORNING REVOLVING
AROUND SFC LOW SITUATED IN SERN NEB. AT THIS POINT EXPECT ACTIVITY
TO CONTINUE AT ALL TERMINALS THRU AT LEAST 10Z THIS MORNING. AFT
10Z...CONDITIONS AT KOFK DETERIORATE TO MVFR/IFR TERRITORY THRU ABOUT
MID MORNING. AS FOR KOMA/KLNK...HAVE TEMPO GROUPS IN PLACE TO TSRA
ACTIVITY BTWN 06Z-10Z. THEREAFTER...VFR CONDITIONS SHOULD PREVAIL
AT BOTH TAF SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 PM EDT FRI AUG 28 2015
.SYNOPSIS...
A WEAK FRONT WILL MEANDER OFF THE THE COAST AS HIGH PRESSURE
SLOWLY BUILDS INTO THE CAROLINAS OVER THE WEEKEND. ERIKA IS
EXPECTED TO APPROACH THE BAHAMAS AND SOUTH FLORIDA LATE IN THE
WEEKEND TRACKING THROUGH FLORIDA INTO EARLY NEXT WEEK...AND
POSSIBLY REMAINING ON A MORE WESTWARD TRACK CLOSER TO THE GULF
COAST.
&&
.NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...HAVE SLIGHTLY
CONTINUED THE DOWNWARD TREND IN SKY COVER AND TEMPTED TO DO THE SAME
WITH RAIN CHANCES. NEITHER THE 12KM WRF, HRRR, OR RUC BRING ANYTHING
MEASURABLE ONSHORE. WILL WAIT ONE MORE CYCLE TO MONITOR CU
DEVELOPMENT AS WELL AS FORMATION OF NE RESULTANT SEABREEZE THAT MAY
GRAB AN OFFSHORE SHOWER AND FLING IT ASHORE. BEST CHANCE WOULD BE
BALD HEAD ISLAND/SOUTHPORT AREAS. PREVIOUS DISCUSSION FOLLOWS:
AS OF 650 AM FRIDAY...HAVE STAYED WITH A DRIER BIAS FOR THIS NEAR
TERM FORECAST...AND KEPT THE THREAT FOR LOW CHANCE POPS ACROSS THE
COASTAL COUNTIES WITH DIURNALLY DRIVEN CONVECTION THE MAIN
EMPHASIS FROM LATE THIS MORNING THRU EARLY THIS EVENING.
LATEST WATER VAPOR IMAGERY INDICATES A MUCH DRIER PICTURE COMPARED
THIS TIME YESTERDAY MORNING. PROGGED MODEL SOUNDINGS INDICATE DRY
AIR BETWEEN 350 MB AND 900 MB BECOMING MORE DOMINANT ACROSS THE FA
LATER THIS MORNING THRU TONIGHT AND INTO THE SHORT TERM PERIOD.
THE SOMEWHAT STALLED SFC BOUNDARY ORIENTED NE-SW AND PARALLEL TO
THE ILM CWA COASTLINE...WILL DRIFT SLIGHTLY FURTHER OFFSHORE THIS
PERIOD. THIS HAS ALREADY ALLOWED THE MODEST 1020+ SFC HIGH
BROADLY CENTERED OVER THE NE STATES AND MID-ATLANTIC TO RIDGE OR
NOSE SOUTH-SOUTHWESTWARD PUSHING DRIER AIR AND LOWER SFC DEWPOINTS
TO AND ACROSS THE ILM CWA. ALREADY OBSERVING WIDESPREAD 60S
DEWPOINTS ACROSS THE FA...ALL THE WAY TO THE IMMEDIATE COAST.
MODELS INDICATE POSSIBLY AROUND 60 THIS AFTN ACROSS THE
NORTHERNMOST PORTIONS OF THE FA THIS AFTN WHERE MIXING OF DRIER
AIR ALOFT TO THE SFC MAY OCCUR. WITH ALL THIS SAID...THE BEST
FORCING/LIFT FOR CONVECTION WILL INITIALLY START JUST ALONG AND
OFF THE IMMEDIATE COAST...AND SWITCH FURTHER EAST AND FURTHER OFF
THE MAINLAND AS THE BOUNDARY LAYER ASSOCIATED WITH THE STALLED SFC
FRONT DRIFTS EASTWARD.
HAVE ALSO GONE WITH OVERALL LESS CLOUD COVERAGE...ESPECIALLY
TONIGHT WHERE ANY DEBRIS CONVECTIVE CLOUDS WILL EITHER STAY
WITHIN THE MEAN FLOW OVER THE ATL WATERS...OR THE DEBRIS CLOUDS
THAT PUSH N-NE FROM GA WILL SCOUR OUT A GOOD DEAL PRIOR TO PUSHING
ACROSS THE FA.
AS FOR TEMPS...LOOKING AT WIDESPREAD 80S FOR MAX TEMPS
TODAY...AND WIDESPREAD 60S FOR MINS EXCEPT NEAR 70 ALONG THE
IMMEDIATE COAST AND EXTREME SOUTHERN PORTIONS OF THE FA. STAYED
WITH A SLIGHTLY COOLER BIAS FOR TONIGHTS MINS USING THE LATEST
AVBL MODEL MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...DRY AIR CONTINUES TO FUNNEL INTO THE AREA
IN NORTHERLY FLOW ON BACK END OF LINGERING FRONT/TROUGH/OFF SHORE
ON SAT. A WAVE OF LOW PRESSURE DEVELOPS ALONG THE FRONT AND LIFTS
OFF TO THE NORTHEAST THROUGH LATE SAT INTO SUN LEAVING WEAK HIGH
PRESSURE OVER THE AREA THROUGH SUN NIGHT. THE NORTHERLY FLOW
BETWEEN HIGH PRESSURE INLAND AND LOW OFF SHORE ON SAT WILL BEGIN
TO VEER AROUND BECOMING MORE ON SHORE THROUGH SUNDAY. ABOVE THE
SURFACE...LOW PRESSURE ALOFT OVER THE CENTRAL GULF COAST WILL
BEGIN TO MOVE SLOWLY NORTHEAST AND WEAKEN PROVIDING A STEADY
SOUTHERLY FLOW OF MOISTURE INTO THE CAROLINAS IN THE LOW TO MID
LEVELS SAT NIGHT INTO SUNDAY. THIS IS DEPICTED WELL BY THE
MOISTURE PROFILES AND GUIDANCE SHOWING A DEEPENING OF MOISTURE
THROUGH THE COLUMN AND AN INCREASE IN CLOUD COVER ON SUNDAY. WITH
SUCH DRY AIR IN PLACE IN THE BEGINNING OF PERIOD...EXPECT LIMITED
TO NO SHWR ACTIVITY WITH A FEW SHWRS/TSTMS POSSIBLE IN LOCALIZED
CONVERGENCE MAINLY ASSOCIATED WITH THE SEA BREEZE OVER THE
WEEKEND...WITH MAINLY SOME HIGHER LEVEL CLOUDS AROUND. PCP WATER
VALUES DOWN LESS THAN AN INCH OVER INLAND NORTH CAROLINA INCREASE
UP TO 1.25 INCHES BY SAT EVE AND UP CLOSE TO 1.5 TO 1.75 INCHES
BY SUN AFTN IN A SLOW INCREASE IN MAINLY UPPER LEVEL MOISTURE.
THEREFORE EXPECT BETTER CHC OF CONVECTION ON SUNDAY BUT
GFS AND ECMWF BOTH SHOWING A WEAKENED ERIKA REACHING OVER SOUTHEAST
FLORIDA COAST SUN NIGHT INTO MON WITH EASTERLY FETCH OF MOISTURE
REACHING AS FAR NORTH AS SOUTH CAROLINA. OVERALL WESTWARD
ADJUSTMENT BY NHC AND GUIDANCE IS EVEN FARTHER WEST. MUCH
UNCERTAINTY STILL EXISTS WITH TRACK AND INTENSITY AND THEREFORE
WILL NEED TO ADJUST IN FUTURE FORECASTS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM FRIDAY...TRENDING DRIER IN OVERALL FORECAST AS LATEST
MODEL RUNS SHOW ERIKA OVER FLORIDA ON MONDAY AND THEN TAKING A
TURN IN GEORGIA OR POSSIBLY TRACKING ACROSS FLORIDA TOWARD THE
GULF COAST. THIS WOULD PRODUCE A GREATER EXTENDED EAST TO
NORTHEASTERLY FETCH OVER THE CAROLINAS. FOR NOW KEPT WITH LOWER
END CHC POPS AND WITH GREATEST IMPACTS FROM ERIKA STILL EXPECTED
MID WEEK...WED INTO THURS. IF ERIKA DOES TAKE A TRACK TO OUR SOUTH
MAY END UP WITH MORE IN THE WAY OF SOME GUSTY ON SHORE WINDS AND
EXTENDED SWELL ENERGY PRODUCING SOME COASTAL IMPACTS BUT WITH SUCH
UNCERTAINTY IN THE MODELS IT IS STILL DIFFICULT TO SAY WITH ANY
CERTAINTY. LATEST GFS KEEPS PCP WATER VALUES LOWER THAN 1.5 INCHES
THROUGH MOST OF PERIOD OVER NC WITH VALUES REACHING UP CLOSE TO 2
INCHES ON NORTHERN STRETCH OF ERIKA INTO SOUTH CAROLINA. UPPER
RIDGE BUILDING OVER THE EASTERN CONUS WILL LEAVE A WEAKNESS BUT
TRACK WILL ALSO BE DEPENDENT ON STRENGTH OF ERIKA AS SHE MAKES HER
WEST NORTHWEST. THE GFS WANTS TO PULL ERIKA TOWARD THE WEST
GETTING PULLED BY THE MID TO UPPER LOW OVER THE WESTERN GULF.
OVERALL WENT A BIT MORE OPTIMISTIC FOR OUR AREA WITH A BIT LESS
CLOUD COVER AND LESS WIDESPREAD CONVECTION. RAISED MAX TEMPS A
BIT...EXPECTING MID TO UPPER 80S MOST PLACES WITH LOWS IN THE LOW
TO MID 70S.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
AS OF 18Z...A FRONTAL SYSTEM IS LOCATED JUST OFF THE COAST THIS
AFTERNOON WITH ISOLATED SHOWERS ALONG IT. AN AREA OF HIGH PRESSURE
IS TO THE N OF THE TERMINALS AND IS SHOWING SIGNS OF BUILDING SOUTH.
WINDS WILL BE NE-ENE THIS AFTERNOON AT 10-15 KTS AT ALL TERMINALS.
TEMPO MVFR CIGS WILL BE POSSIBLE EARLY THIS AFTERNOON AT THE COASTAL
TERMINALS...BUT GENERALLY SCT/BKN LOW VFR CIGS EXPECTED THROUGH
MIDNIGHT Z. SCT SKIES EXPECTED AT KFLO/KLBT.
WINDS DECREASE THIS EVENING TO NE AT 5 KT OR LESS. GUIDANCE IS
SUGGESTING FOG DEVELOPMENT OVERNIGHT WITH BEST CHANCE AT KLBT WHERE
WINDS ARE LIGHTEST. SINCE DEWPOINTS ARE RELATIVELY LOW AND GROUND
TEMPS WARM THINK CHANCES ARE LOW ATTM. VFR AFTER SUNRISE WITH NE
WINDS.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING
FOG/STRATUS IS ALSO EXPECTED EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...MODERATE NE
SURGE OF DRY AIR CONTINUES...POSSIBLY STEADY STATE FOR THE NEXT
HANDFUL OF HOURS BUT STARTING TO ABATE AROUND MIDDAY. THIS HAS
GOTTEN WAVE FACES RATHER STEEP BUT NOT QUITE SCEC-WORTHY IN HEIGHT.
THERE ARE NO CHANGES TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS:
AS OF 650 AM FRIDAY...THE ENTIRE ILM COASTAL WATERS SHOULD NOW BE
ENCOMPASSED WITH A STEADY AND MODEST NE WIND. THE SFC PG FROM THE
RIDGING FROM THE 1020+ HIGH FROM THE NORTH WILL BE TIGHT ENOUGH TO
PRODUCE A SOLID 15 KT SUSTAINED WIND...EXCEPT INITIALLY 15 TO 20
KT ACROSS THE ILM NC WATERS. LOOKING AT KLTX VWP AND ADJACENT 88D
VWPS...WINDS 1K TO 2K FT OFF THE DECK ARE RUNNING NE-ENE AT 15 TO
30 KT. WITH SOME OF THIS MIXING DOWN TO THE OCEAN SFC AS 20+ WIND
GUSTS. LOOK FOR A SOLID 15 KT NE WIND SPEED TONIGHT FOR ALL
WATERS...WIND DIRECTIONS MAY BRIEFLY VEER TO THE ENE-E NEAR SHORE
THIS AFTN/EARLY EVENING DUE TO A RESULTANT WIND BOUNDARY.
SIGNIFICANT SEAS WILL RUN A SOLID 4 FT FOR THE ILM NC WATERS FROM
CAPE FEAR NORTHWARD THRU THE PERIOD...AND 2 TO 4 FT SOUTH OF THE
CAPE. THE 4 TO 6 SECOND PERIOD WIND WAVES WILL DOMINATE THE
SIGNIFICANT SEAS...WITH THE UNDERLYING 1 TO 1.5 FOOT ESE GROUND
SWELL AT 11-12 SECOND PERIODS REMAINING VISUALLY PRESENT. THE
SCATTERED CONVECTION COVERAGE ASSOCIATED WITH THE SOMEWHAT STALLED
SFC FRONT...WILL SWITCH TO THE ADJACENT OFFSHORE WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...NORTHEAST WINDS ON SATURDAY BETWEEN HIGH
PRESSURE EXTENDING DOWN OVER THE CAROLINAS AND WEAK LOW PRESSURE
DEVELOPING ALONG LINGERING BOUNDARY OFF SHORE. AS THIS LOW PULLS
AWAY THROUGH SUNDAY...WINDS MAY COME AROUND TO A MORE EASTERLY ON
SHORE DIRECTION AROUND HIGH PRESSURE. EXPECT DEEPEST MOISTURE AND
CONVECTION MAINLY EAST OF WATERS ASSOCIATED WITH LINGERING
BOUNDARY AND WAVE OF LOW PRESSURE ALONG IT. LATEST FORECAST TRACKS
WEAKENED ERIKA OVER FLORIDA BY SUNDAY NIGHT INTO EARLY MONDAY.
THIS WOULD MAINLY PRODUCE EASTERLY SWELL ENERGY REACHING INTO THE
LOCAL WATERS OVER THE WEEKEND WITH SEAS BASICALLY REMAINING 2 TO 4
FT MOST WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...LATEST FORECAST TRACKS ERIKA OVER FLORIDA
AND KEEPS TRENDING WESTWARD WITH TIME GETTING PULLED BY MID TO
UPPER LOW IN THE WESTERN GULF. MAY SEE WINDS REMAIN E-NE ONLY
RISING UP TO 15 KTS. WITH SO MUCH UNCERTAINTY IN MODEL RUNS...WILL
NEED TO KEEP AN EYE ON EVOLUTION OF ERIKA. FOR NOW WILL KEEP
MAINLY EAST WINDS LESS THAN 15 KTS AND SEAS BASICALLY 2 TO 4 FT
WITH A DIMINISHING LONGER PERIOD SWELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...MBB/DCH
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1015 AM EDT FRI AUG 28 2015
.SYNOPSIS...
A WEAK FRONT WILL MEANDER OFF THE THE COAST AS HIGH PRESSURE
SLOWLY BUILDS INTO THE CAROLINAS OVER THE WEEKEND. ERIKA IS
EXPECTED TO APPROACH THE BAHAMAS AND SOUTH FLORIDA LATE IN THE
WEEKEND TRACKING THROUGH FLORIDA INTO EARLY NEXT WEEK...AND
POSSIBLY REMAINING ON A MORE WESTWARD TRACK CLOSER TO THE GULF
COAST.
&&
.NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...HAVE SLIGHTLY
CONTINUED THE DOWNWARD TREND IN SKY COVER AND TEMPTED TO DO THE SAME
WITH RAIN CHANCES. NEITHER THE 12KM WRF, HRRR, OR RUC BRING ANYTHING
MEASUREABLE ONSHORE. WILL WAIT ONE MORE CYCLE TO MONITOR CU
DEVELOPMENT AS WELL AS FORMATION OF NE RESULTANT SEABREEZE THAT MAY
GRAB AN OFFSHORE SHOWER AND FLING IT ASHORE. BEST CHANCE WOULD BE
BALD HEAD ISLAND/SOUTHPORT AREAS. PREVIOUS DISCUSSION FOLLOWS:
AS OF 650 AM FRIDAY...HAVE STAYED WITH A DRIER BIAS FOR THIS NEAR
TERM FORECAST...AND KEPT THE THREAT FOR LOW CHANCE POPS ACROSS THE
COASTAL COUNTIES WITH DIURNALLY DRIVEN CONVECTION THE MAIN
EMPHASIS FROM LATE THIS MORNING THRU EARLY THIS EVENING.
LATEST WATER VAPOR IMAGERY INDICATES A MUCH DRIER PICTURE COMPARED
THIS TIME YESTERDAY MORNING. PROGGED MODEL SOUNDINGS INDICATE DRY
AIR BETWEEN 350 MB AND 900 MB BECOMING MORE DOMINANT ACROSS THE FA
LATER THIS MORNING THRU TONIGHT AND INTO THE SHORT TERM PERIOD.
THE SOMEWHAT STALLED SFC BOUNDARY ORIENTED NE-SW AND PARALLEL TO
THE ILM CWA COASTLINE...WILL DRIFT SLIGHTLY FURTHER OFFSHORE THIS
PERIOD. THIS HAS ALREADY ALLOWED THE MODEST 1020+ SFC HIGH
BROADLY CENTERED OVER THE NE STATES AND MID-ATLANTIC TO RIDGE OR
NOSE SOUTH-SOUTHWESTWARD PUSHING DRIER AIR AND LOWER SFC DEWPOINTS
TO AND ACROSS THE ILM CWA. ALREADY OBSERVING WIDESPREAD 60S
DEWPOINTS ACROSS THE FA...ALL THE WAY TO THE IMMEDIATE COAST.
MODELS INDICATE POSSIBLY AROUND 60 THIS AFTN ACROSS THE
NORTHERNMOST PORTIONS OF THE FA THIS AFTN WHERE MIXING OF DRIER
AIR ALOFT TO THE SFC MAY OCCUR. WITH ALL THIS SAID...THE BEST
FORCING/LIFT FOR CONVECTION WILL INITIALLY START JUST ALONG AND
OFF THE IMMEDIATE COAST...AND SWITCH FURTHER EAST AND FURTHER OFF
THE MAINLAND AS THE BOUNDARY LAYER ASSOCIATED WITH THE STALLED SFC
FRONT DRIFTS EASTWARD.
HAVE ALSO GONE WITH OVERALL LESS CLOUD COVERAGE...ESPECIALLY
TONIGHT WHERE ANY DEBRIS CONVECTIVE CLOUDS WILL EITHER STAY
WITHIN THE MEAN FLOW OVER THE ATL WATERS...OR THE DEBRIS CLOUDS
THAT PUSH N-NE FROM GA WILL SCOUR OUT A GOOD DEAL PRIOR TO PUSHING
ACROSS THE FA.
AS FOR TEMPS...LOOKING AT WIDESPREAD 80S FOR MAX TEMPS
TODAY...AND WIDESPREAD 60S FOR MINS EXCEPT NEAR 70 ALONG THE
IMMEDIATE COAST AND EXTREME SOUTHERN PORTIONS OF THE FA. STAYED
WITH A SLIGHTLY COOLER BIAS FOR TONIGHTS MINS USING THE LATEST
AVBL MODEL MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...DRY AIR CONTINUES TO FUNNEL INTO THE AREA
IN NORTHERLY FLOW ON BACK END OF LINGERING FRONT/TROUGH/OFF SHORE
ON SAT. A WAVE OF LOW PRESSURE DEVELOPS ALONG THE FRONT AND LIFTS
OFF TO THE NORTHEAST THROUGH LATE SAT INTO SUN LEAVING WEAK HIGH
PRESSURE OVER THE AREA THROUGH SUN NIGHT. THE NORTHERLY FLOW
BETWEEN HIGH PRESSURE INLAND AND LOW OFF SHORE ON SAT WILL BEGIN
TO VEER AROUND BECOMING MORE ON SHORE THROUGH SUNDAY. ABOVE THE
SURFACE...LOW PRESSURE ALOFT OVER THE CENTRAL GULF COAST WILL
BEGIN TO MOVE SLOWLY NORTHEAST AND WEAKEN PROVIDING A STEADY
SOUTHERLY FLOW OF MOISTURE INTO THE CAROLINAS IN THE LOW TO MID
LEVELS SAT NIGHT INTO SUNDAY. THIS IS DEPICTED WELL BY THE
MOISTURE PROFILES AND GUIDANCE SHOWING A DEEPENING OF MOISTURE
THROUGH THE COLUMN AND AN INCREASE IN CLOUD COVER ON SUNDAY. WITH
SUCH DRY AIR IN PLACE IN THE BEGINNING OF PERIOD...EXPECT LIMITED
TO NO SHWR ACTIVITY WITH A FEW SHWRS/TSTMS POSSIBLE IN LOCALIZED
CONVERGENCE MAINLY ASSOCIATED WITH THE SEA BREEZE OVER THE
WEEKEND...WITH MAINLY SOME HIGHER LEVEL CLOUDS AROUND. PCP WATER
VALUES DOWN LESS THAN AN INCH OVER INLAND NORTH CAROLINA INCREASE
UP TO 1.25 INCHES BY SAT EVE AND UP CLOSE TO 1.5 TO 1.75 INCHES
BY SUN AFTN IN A SLOW INCREASE IN MAINLY UPPER LEVEL MOISTURE.
THEREFORE EXPECT BETTER CHC OF CONVECTION ON SUNDAY BUT
GFS AND ECMWF BOTH SHOWING A WEAKENED ERIKA REACHING OVER SOUTHEAST
FLORIDA COAST SUN NIGHT INTO MON WITH EASTERLY FETCH OF MOISTURE
REACHING AS FAR NORTH AS SOUTH CAROLINA. OVERALL WESTWARD
ADJUSTMENT BY NHC AND GUIDANCE IS EVEN FARTHER WEST. MUCH
UNCERTAINTY STILL EXISTS WITH TRACK AND INTENSITY AND THEREFORE
WILL NEED TO ADJUST IN FUTURE FORECASTS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 330 AM FRIDAY...TRENDING DRIER IN OVERALL FORECAST AS LATEST
MODEL RUNS SHOW ERIKA OVER FLORIDA ON MONDAY AND THEN TAKING A
TURN IN GEORGIA OR POSSIBLY TRACKING ACROSS FLORIDA TOWARD THE
GULF COAST. THIS WOULD PRODUCE A GREATER EXTENDED EAST TO
NORTHEASTERLY FETCH OVER THE CAROLINAS. FOR NOW KEPT WITH LOWER
END CHC POPS AND WITH GREATEST IMPACTS FROM ERIKA STILL EXPECTED
MID WEEK...WED INTO THURS. IF ERIKA DOES TAKE A TRACK TO OUR SOUTH
MAY END UP WITH MORE IN THE WAY OF SOME GUSTY ON SHORE WINDS AND
EXTENDED SWELL ENERGY PRODUCING SOME COASTAL IMPACTS BUT WITH SUCH
UNCERTAINTY IN THE MODELS IT IS STILL DIFFICULT TO SAY WITH ANY
CERTAINTY. LATEST GFS KEEPS PCP WATER VALUES LOWER THAN 1.5 INCHES
THROUGH MOST OF PERIOD OVER NC WITH VALUES REACHING UP CLOSE TO 2
INCHES ON NORTHERN STRETCH OF ERIKA INTO SOUTH CAROLINA. UPPER
RIDGE BUILDING OVER THE EASTERN CONUS WILL LEAVE A WEAKNESS BUT
TRACK WILL ALSO BE DEPENDENT ON STRENGTH OF ERIKA AS SHE MAKES HER
WEST NORTHWEST. THE GFS WANTS TO PULL ERIKA TOWARD THE WEST
GETTING PULLED BY THE MID TO UPPER LOW OVER THE WESTERN GULF.
OVERALL WENT A BIT MORE OPTIMISTIC FOR OUR AREA WITH A BIT LESS
CLOUD COVER AND LESS WIDESPREAD CONVECTION. RAISED MAX TEMPS A
BIT...EXPECTING MID TO UPPER 80S MOST PLACES WITH LOWS IN THE LOW
TO MID 70S.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...A FRONTAL SYSTEM IS LOCATED JUST OFF THE COAST THIS
MORNING WITH ISOLATED SHOWERS ALONG IT. AN AREA OF HIGH PRESSURE IS
TO THE N OF THE TERMINALS. AS A RESULT WINDS WILL BE NE-ENE TODAY AT
10-15 KTS AT ALL TERMINALS. DESPITE SOME IFR CIGS SOUTH OF KMYR VFR
WILL BE LIKELY TODAY. THERE IS ENOUGH MOISTURE TO HAVE SCT/BKN VFR
CIGS THROUGH MIDNIGHT Z AT THE COASTAL TERMINALS. SCT SKIES EXPECTED
AT KFLO/KLBT THROUGH THE TAF VALID PERIOD.
A LOW PRESSURE AREA WILL DEVELOP ALONG THE FRONT TODAY AND MOVE NE.
THERE IS A CHANCE SHOWERS OFFSHORE COULD MOVE TO NEAR THE COASTAL
TERMINALS...BUT ALL OF THE LATEST GUIDANCE SUGGEST THE CHANCE IS
VERY SMALL. THE BEST CHANCE HOWEVER...WOULD BE KMYR IN THE LATE
EVENING OR EARLY MORNING HOURS. WINDS DECREASE THIS EVENING TO 5 KT
OR LESS. GUIDANCE IS SUGGESTING FOG DEVELOPMENT OVERNIGHT WITH BEST
CHANCE AT KLBT. WILL NOT ADDRESS THIS IN TAFS ATTM.
EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING
FOG/STRATUS IS ALSO EXPECTED EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM FRIDAY...MODERATE NE
SURGE OF DRY AIR CONTINUES...POSSIBLY STEADY STATE FOR THE NEXT
HANDFUL OF HOURS BUT STARTING TO ABATE AROUND MIDDAY. THIS HAS
GOTTEN WAVE FACES RATHER STEEP BUT NOT QUITE SCEC-WORTHY IN HEIGHT.
THERE ARE NO CHANGES TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS:
AS OF 650 AM FRIDAY...THE ENTIRE ILM COASTAL WATERS SHOULD NOW BE
ENCOMPASSED WITH A STEADY AND MODEST NE WIND. THE SFC PG FROM THE
RIDGING FROM THE 1020+ HIGH FROM THE NORTH WILL BE TIGHT ENOUGH TO
PRODUCE A SOLID 15 KT SUSTAINED WIND...EXCEPT INITIALLY 15 TO 20
KT ACROSS THE ILM NC WATERS. LOOKING AT KLTX VWP AND ADJACENT 88D
VWPS...WINDS 1K TO 2K FT OFF THE DECK ARE RUNNING NE-ENE AT 15 TO
30 KT. WITH SOME OF THIS MIXING DOWN TO THE OCEAN SFC AS 20+ WIND
GUSTS. LOOK FOR A SOLID 15 KT NE WIND SPEED TONIGHT FOR ALL
WATERS...WIND DIRECTIONS MAY BRIEFLY VEER TO THE ENE-E NEAR SHORE
THIS AFTN/EARLY EVENING DUE TO A RESULTANT WIND BOUNDARY.
SIGNIFICANT SEAS WILL RUN A SOLID 4 FT FOR THE ILM NC WATERS FROM
CAPE FEAR NORTHWARD THRU THE PERIOD...AND 2 TO 4 FT SOUTH OF THE
CAPE. THE 4 TO 6 SECOND PERIOD WIND WAVES WILL DOMINATE THE
SIGNIFICANT SEAS...WITH THE UNDERLYING 1 TO 1.5 FOOT ESE GROUND
SWELL AT 11-12 SECOND PERIODS REMAINING VISUALLY PRESENT. THE
SCATTERED CONVECTION COVERAGE ASSOCIATED WITH THE SOMEWHAT STALLED
SFC FRONT...WILL SWITCH TO THE ADJACENT OFFSHORE WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 AM FRIDAY...NORTHEAST WINDS ON SATURDAY BETWEEN HIGH
PRESSURE EXTENDING DOWN OVER THE CAROLINAS AND WEAK LOW PRESSURE
DEVELOPING ALONG LINGERING BOUNDARY OFF SHORE. AS THIS LOW PULLS
AWAY THROUGH SUNDAY...WINDS MAY COME AROUND TO A MORE EASTERLY ON
SHORE DIRECTION AROUND HIGH PRESSURE. EXPECT DEEPEST MOISTURE AND
CONVECTION MAINLY EAST OF WATERS ASSOCIATED WITH LINGERING
BOUNDARY AND WAVE OF LOW PRESSURE ALONG IT. LATEST FORECAST TRACKS
WEAKENED ERIKA OVER FLORIDA BY SUNDAY NIGHT INTO EARLY MONDAY.
THIS WOULD MAINLY PRODUCE EASTERLY SWELL ENERGY REACHING INTO THE
LOCAL WATERS OVER THE WEEKEND WITH SEAS BASICALLY REMAINING 2 TO 4
FT MOST WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 330 AM FRIDAY...LATEST FORECAST TRACKS ERIKA OVER FLORIDA
AND KEEPS TRENDING WESTWARD WITH TIME GETTING PULLED BY MID TO
UPPER LOW IN THE WESTERN GULF. MAY SEE WINDS REMAIN E-NE ONLY
RISING UP TO 15 KTS. WITH SO MUCH UNCERTAINTY IN MODEL RUNS...WILL
NEED TO KEEP AN EYE ON EVOLUTION OF ERIKA. FOR NOW WILL KEEP
MAINLY EAST WINDS LESS THAN 15 KTS AND SEAS BASICALLY 2 TO 4 FT
WITH A DIMINISHING LONGER PERIOD SWELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...MBB/DCH
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
.
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1249 AM EDT FRI AUG 28 2015
.SYNOPSIS...
A STATIONARY FRONT OFF THE COAST WILL DRIFT SLOWLY EAST THROUGH
THE WEEKEND AS WEAK HIGH PRESSURE BUILDS INTO THE AREA FROM THE
NORTH. TROPICAL CYCLONE ERIKA IS FORECAST TO BE IN THE VICINITY OF
THE SOUTHEAST COAST EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM FRIDAY...HAVE ADJUSTED POPS DOWN AS MOST OF THE
ACTIVITY IS NOW OFFSHORE. WILL KEEP JUST A SLIGHT CHANCE OF
PRECIPITATION ALONG THE COAST OVERNIGHT. REST OF FORECAST IN
PRETTY GOOD SHAPE. MID/HIGH CLOUDS WILL CONTINUE TO PREVAIL
OVERNIGHT WITH LOW TEMPERATURE FORECAST IN THE MID 60S INLAND TO
AROUND 70 LOOKING GOOD.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SATURDAY/...
AS OF 240 PM THURSDAY...DEEPER MOISTURE WILL GRAD MOVE FURTHER E
FRI AS HIGH PRES BUILDS CLOSER AND THE FRONT/LOW OFFSHORE MOVES
FURTHER E. EXPECT DRY CONDITIONS INLAND WITH A SLIGHT CHC TO CHC
POP IMD CST...ESPCLY EARLY. WITH MORE SUN INLAND SHLD SEE HIGHS
AROUND 85 WITH LOWER 80S CST.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
AS OF 335 PM THURSDAY...WEAK ZONAL FLOW DEVELOPS FRIDAY WITH THE
UPPER RIDGE OVER BERMUDA BUILDING WEST TOWARDS THE SOUTHEASTERN
STATES. AT THE SURFACE, A WEAK FRONT WILL REMAIN STALL OFF THE NC
COAST THROUGH SATURDAY.
LITTLE CHANGE IN FORECAST REASONING BASED ON 12Z GUIDANCE THROUGH
THE PERIOD. THE FRONTAL BOUNDARY AND DEEPEST MOISTURE REMAINS
STALLED OFFSHORE THROUGH FRIDAY NIGHT AND WILL MAINTAIN DRY
CONDITIONS INLAND TO SLIGHT CHANCE POPS FOR COASTAL SECTIONS.
THE UPPER RIDGE ACROSS THE WESTERN ATLANTIC BUILDS WEST INTO THE
SOUTHEAST FRIDAY THROUGH EARLY NEXT WEEK WHILE A ROBUST NORTHERN
STREAM SHORTWAVE MOVES ACROSS THE MIDWEST INTO THE WEEKEND. A BROAD
SHORTWAVE WILL LIFT NORTHEAST AROUND THE WESTERN PERIPHERY OF THE
UPPER RIDGE SATURDAY NIGHT THROUGH SUNDAY, THOUGH WILL REMAIN FAR
ENOUGH NORTH AND WEST OF THE REGION TO HAVE LITTLE IMPACT. AT THE
SURFACE, HIGH PRESSURE WILL SHIFT OFF THE MID-ATLANTIC COAST LATE
FRIDAY AND RIDGE SOUTHWEST INTO EASTERN NC FRIDAY NIGHT INTO
SATURDAY, THEN TRANSITION OFFSHORE WITH THE PIEDMONT TROUGH
DEVELOPING SUNDAY THROUGH TUESDAY. WILL MAINTAIN SLIGHT CHANCE
POPS FOR DIURNALLY DRIVEN, MAINLY ISOLATED, SHOWER/THUNDERSTORM
PATTERN THROUGH THE WEEKEND AND INTO TUESDAY. TEMPERATURES WILL
BE NEAR OR A FEW DEGREES ABOVE CLIMATOLOGY FOR LATE AUGUST.
THE FORECAST FOR WEDNESDAY AND THURSDAY, DAY 7/8, IS PARTICULARLY
TRICKY DUE TO THE UNCERTAINTY IN ANY TROPICAL IMPACTS FROM
TROPICAL STORM ERIKA, CURRENTLY SOUTHEAST OF PUERTO RICO. WILL
HEDGE TOWARDS A MODEL BLEND FOR THIS PERIOD WITH SLIGHT CHANCE
POPS WEDNESDAY INCREASING TO CHANCE POPS THURSDAY, AS SURFACE FLOW
SHIFTS SOUTHEASTERLY AND ABUNDANT MOISTURE OVERSPREADS EASTERN NC.
THE FOCUS WILL BE ON THE TROPICS THIS WEEKEND AS THE NATIONAL
HURRICANE CENTER HAS TROPICAL STORM ERIKA FORECAST TO MOVE INTO
THE BAHAMAS. SIGNIFICANT UNCERTAINTY CONTINUES WITH REGARDS TO
THE STRENGTH AND TRACK OF THE SYSTEM BEYOND DAY 3 WITH POOR RUN TO
RUN CONSISTENCY IN THE MODELS, THUS IT IS TOO SOON TO SPECULATE AT
THIS TIME WHAT IMPACTS MAY BE FELT ACROSS THE REGION NEXT WEEK.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 06Z SATURDAY/...
AS OF 1245 AM FRIDAY...HAVE CONTINUED TREND OF VFR FORECAST
THROUGH THE PERIOD. MID TO HIGH CLOUDS WILL PREVAIL OVERNIGHT AND
WITH WEAK BOUNDARY LAYER MIXING DO NOT EXPECT MUCH IN THE WAY OF
FOG OR STRATUS FORMATION OVERNIGHT. DRIER AIR ADVECTS INTO THE
REGION FOR FRIDAY INTO FRIDAY NIGHT WITH VFR CONDITIONS
PREVAILING.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 340 PM THURSDAY...PREDOMINANT VFR CONDITIONS EXPECTED
THROUGH TUESDAY WITH ONLY ISOLATED, MAINLY DIURNALLY DRIVEN
SHRA/TSRA.
&&
.MARINE...
SHORT TERM /THROUGH FRI/...
AS OF 1245 AM FRIDAY...GUSTY NORTHEAST WINDS OVER THE PAMLICO
SOUND AND SOME OF THE CENTRAL AND NORTHERN WATERS. THE HRRR AND
RUC ARE PICKING UP WELL ON THESE WINDS AND HAVE USED A BLEND OF
THESE WIND FIELDS FOR THE VERY NEAR TERM. SEAS CONTINUE IN THE 3
TO 5 FEET RANGE AND THIS SHOULD PERSIST OVERNIGHT. ON FRI THE
HIGH BUILDS JUST TO THE N AS THE LOW/FRONT DRIFTS FURTHER E. THIS
SHLD LEAD TO NE WINDS DIMINISHING TO 10 TO 15 KTS. THE PERSISTENT
FETCH WILL KEEP SEAS 3 TO 5 FEET...HIGHEST OUTER WATERS.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 340 PM THURSDAY...THE HIGH WILL SHIFT OFF THE MID-ATLANTIC
COAST FRIDAY NIGHT INTO SATURDAY WITH WINDS AROUND 15 KT OR LESS
SATURDAY, DIMINISHING TO 10 KT OR LESS BY SUNDAY. WIND DIRECTION
WILL GENERALLY BE NORTHEAST SATURDAY AND SUNDAY, VEERING SOUTHEAST
SUNDAY NIGHT THEN SOUTH MONDAY INTO TUESDAY. WIND SPEEDS WILL
BECOME LESS THAN 10 KT SUNDAY NIGHT THROUGH MONDAY NIGHT DUE TO
WEAK PRESSURE GRADIENT ACROSS THE EASTERN NC COASTAL WATERS. SEAS
WILL RANGE 2-3 FT THROUGH THE LONG TERM WITH SOME 4 FT SEAS FOR
THE OUTER CENTRAL WATERS. LOCAL SWAN/NWPS PERFORMING BETTER IN
NORTHEAST WIND/SWELL CONDITIONS SATURDAY, THEN A GENERAL BLEND
WITH WAVEWATCH FOR THE MEDIUM RANGE. MARINE INTERESTS SHOULD
CONTINUE TO MONITOR THE DEVELOPMENT OF TROPICAL STORM ERIKA OVER
THE WEEKEND, CURRENTLY LOCATED SOUTHEAST OF PUERTO RICO.
SIGNIFICANT UNCERTAINTY REMAINS WITH REGARDS TO FORECAST TRACK AND
INTENSITY BEYOND DAY 3.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...DAG
AVIATION...CTC/DAG
MARINE...CTC/JBM/DAG/LEP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
311 PM CDT FRI AUG 28 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 304 PM CDT FRI AUG 28 2015
WATER VAPOR SHOWS THE MAIN SHORT WAVE OVER NW ONTARIO MOVING
TOWARD LAKE SUPERIOR. UPSTREAM IN SOUTHERN MANITOBA ARE SOME OTHER
WEAKER SHORT WAVES. A FEW OTHER WEAKER SHORT WAVES ALSO INTO SOUTH
CENTRAL NORTH DAKOTA. SO PATTERN IS PRETTY MUDDLED ALOFT. AT THE
SFC NOT MUCH BETTER. SHORT RANGE MODELS KEEP INDICATING A SFC
TROUGH ADVANCING INTO THE NRN RRV THIS AFTN AND THEN SINKING SOUTH
THIS LATE AFTN/EVE. SO FAR REAL HARD TO PICK ONE OUT. WINDS ARE
SOUTH-SOUTHWEST TO 25 KTS GRAND FORKS-GRAFTON AND DO SHIFT A TAD
MORE WEST LANGDON-DEVILS LAKE REGION AND THEN IN SOUTHERN MANITOBA
PRETTY LIGHT AND VARIABLE. SO AT THIS POINT HARD TO TELL IF INDEED
A WIND SHIFT LINE WILL ADVANCE SOUTH AS HRRR/RAP/NAM AND NCEP
MODELS SAY. PRETTY UNSTABLE IN NRN ERN ND/NW MN WITH MAX MU CAPES
IN THE 4000 J/KG RANGE NR ROSEAU-HALLOCK...LIKELY IMPACTED BY
HIGHER DEW PTS NOTED BY AWOS`S. THAT SAID CONVECTIVE MODELS
CONTINUE TO INDICATE SOME DEVELOPMENT ALONG A WEAK BOUNDARY
JAMESTOWN-FARGO-BEMIDJI-PARK RAPIDS AREA 00Z-03Z PERIOD. ALSO
DEVELOPMENT WILL CONTINUE OVER LAKE OF THE WOODS. MORE UNCERTAIN
IN THE NRN VALLEY AND FAR NW MN WHERE INSTABILITY MAX IS AS
CONVECTIVE SHORT RANGE MODELS SHOW NOTHING TO DEVELOP BUT OBS MAY
INDICATE ATMOSPHERE PRIMED. SO WILL CONTINUE TO WATCH AND HAVE
POPS IN AREAS AS SHORT RANGE MODELS INDICATE BUT ALBEIT A BIT
WIDER AREA. INTO SATURDAY THE HEAT AND HUMIDITY IS ON AS UPPER
RIDGE BUILDS IN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 304 PM CDT FRI AUG 28 2015
HOT AND HUMID AND A BIT BREEZY ON SUNDAY. NEXT FRONT DUE TO MOVE
THRU LATE SUN NIGHT INTO MONDAY WITH A RISK OF A FEW
SHOWERS/STORMS.
FOR MONDAY NIGHT THROUGH FRIDAY...
THE TREND FOR THIS PERIOD IS GENERALLY WARM AND UNSETTLED. THE
PERIOD STARTS OFF WITH SOUTHWEST FLOW ALOFT OVER THE REGION AND A
WEAK SHORT WAVE MOVING THROUGH THE AREA MONDAY NIGHT. WEAK WAVES
WILL CONTINUE TO AFFECT THE AREA THROUGH MUCH OF THE WEEK...WITH A
WARM/HOT AIR MASS IN PLACE AND OCCASIONAL THUNDERSTORM CHANCES.
MID 80S TO LOW 90S WILL BE COMMON...WITH SOME MID 90S POSSIBLE AS
WELL. TOWARD THE END OF THE WEEK...AN UPPER LEVEL TROUGH/LOW WILL
DEEPEN OVER THE WESTERN STATES...WITH A SURFACE LOW LIKELY
DEVELOPING IN THE NORTHERN PLAINS. THE GFS AND ECMWF DIFFER ON
DETAILS...INCLUDING THE LOCATION OF THE COOLER AIR...BUT BOTH HAVE
A SFC LOW IN THE GENERAL REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 102 PM CDT FRI AUG 28 2015
MODELS ARE STILL HINTING AT THUNDERSTORM DEVELOPMENT POTENTIALLY
THIS AFTERNOON. NAM AND SREF STILL POINT TOWARD ACTIVITY NEAR
TVF/GFK BY MID AFTERNOON. HOWEVER...THE LATEST HRRR KEEPS ACTIVITY
FURTHER EAST AND SOUTH...MORE IN THE KBJI TO KFAR AREAS AROUND 00Z.
REGARDING TS...HAVE MADE ONLY MINOR CHANGES COMPARED TO PREVIOUS
FORECAST. NAM AND SREF ARE SHOWING SIGNS OF BR DEVELOPMENT LATE
TONIGHT. HAVE KEPT IT AT 5SM AROUND SUNRISE AT GFK/BJI/TVF.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...RIDDLE
LONG TERM...KNUTSVIG/RIDDLE
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
107 PM CDT FRI AUG 28 2015
.UPDATE...
ISSUED AT 102 PM CDT FRI AUG 28 2015
BIGGEST QUESTION IS WHERE/IF T-STORMS WILL RE-DEVELOP. SFC OBS
SHOW A SOUTH-SOUTHWEST WIND TO 25 KTS IN THE NRN VALLEY WITH TEMPS
NR 80 AND DEW PTS 65-70 IN MUCH OF THE RRV AND E ND AND FAR NW MN.
A WEAK WIND SHIFT IS NOTED BUT MORE IN CNTRL ND ROLLA-CANDO AREA
AND INTO SW MANITOBA. CONVECTIVE SHORT RANGE MODELS INDICATE A
WEAK WIND SHIFT DROPPING SOUTH THIS AFTN AND SOME STORMS FIRING
FARGO-DETROIT LAKES AREA 00Z OR SO. THAT HAS BEEN A CONSISTENT
SIGNAL BUT YET TROUGH/WIND SHIFT LINE AS DEPICTED BY HRRR STILL AM
NOT SURE WILL OCCUR. TRENDED POPS THE WAY OF THE HRRR AND HOP WRF
MODELS WHICH SO THE FARGO-DTL CONVECTION.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI AUG 28 2015
VISIBILITY ACROSS NORTHWEST MINNESOTA WILL CONTINUE TO BE VARIABLE
IN PATCHY FOG THROUGH THE PREDAWN HOURS... THOUGH ANY FOG SHOULD
DISSIPATE SHORTLY AFTER SUNRISE.
A STRONG THUNDERSTORM COMPLEX IN SOUTHERN MANITOBA THIS HOUR IS
EXPECTED TO DIMINISH IN INTENSITY AS IT BRUSHES THE U.S. BORDER
ACROSS NORTHERN CAVALIER AND KITTSON COUNTIES AROUND 12Z. ISOLATED
SHOWER AND THUNDERSTORM ACTIVITY IS THEN POSSIBLE THROUGH THE
FORENOON THROUGHOUT THE NORTH BORDER COUNTIES... SPREADING ACROSS
FAR NORTHCENTRAL MINNESOTA THROUGH THE EARLY AFTERNOON.
A SECOND ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE...STARTING IN EAST CENTRAL ND FROM MID AFTERNOON AND
SPREADING EASTWARD ALONG AN EAST-WEST ORIENTED TROF AXIS INTO
NORTHWEST MINNESOTA INTO THE EARLY EVENING. EXTENT AND SEVERITY
OF THESE STORMS WILL DEPEND ON AFTERNOON HEATING... WITH AFTERNOON
TEMPERATURES REACHING INTO THE MID 80S IN SPOTS... THUS SOME
STORMS COULD PRODUCE SMALL HAIL AND GUSTY WINDS.
LATER TONIGHT AND SATURDAY WILL SEE A RETURN TO LIGHT SOUTHERLY
FLOW AND A DRIER...MORE STABLE H5 RIDGE BUILDING IN ALOFT.
TEMPERATURES OVERALL WILL BE A BIT WARMER THAN SEASONAL NORMALS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI AUG 28 2015
SATURDAY NIGHT AND SUUNDAY...EXPECT MORE OF THE SAME. WITH A WARM
H5 RIDGE ALOFT AND LIGHT SOUTHERLY WINDS AT THE SURFACE...EXPECT
SEASONABLY WARM AND DRY CONDITIONS WITH HIGH TEMPERATURES RANGING
FRM THEMID 80S IN CENTRAL MINNESOTA LAKES COUNTRY TO THE LOWER 90S
IN THE DEVILS LAKE BASIN.
MONDAY-THURSDAY...A VERY SUMMER-LIKE WEATHER PATTERN WILL CONTINUE
HEADING INTO THE START OF SEPTEMBER. THE UPPER RIDGE WILL FLATTEN
EARLY ON WITH SHORTWAVE ENERGY PASSING NORTH ACROSS CANADA. AN
ASSOCIATED WEAK SFC BOUNDARY COULD FIRE A FEW STORMS OFF ON
MONDAY...ALTHOUGH THE BEST UPPER SUPPORT WILL BE WELL NORTH OVER
CANADA. THIS BOUNDARY SHOULD THEN WASH OUT WITHIN PERSISTENT
SOUTHWESTERLY FLOW ALOFT. NOT VERY OPTIMISTIC ABOUT PRECIP CHANCES
LATER IN THE PERIOD...ALTHOUGH A STORM COULD NOT BE RULED OUT GIVEN
THE SOUTHWEST FLOW PATTERN/RATHER MOIST ENVIRONMENT. WARMER MID-
LEVEL TEMPS MAY ACT TO SUPPRESS CONVECTION BY WED INTO THUR AS THE
PATTERN AMPLIFIES AHEAD OF AN APPROACHING FRONT. DETAILS OUT AT THIS
RANGE ARE STILL QUITE UNCERTAIN THOUGH.
AVE HIGHS/LOWS FALL INTO THE MID TO UPPER 70S/LOW 50S DURING EARLY
SEPT...BUT HIGHS SHOULD SHOULD REACH THE 80S WITH LOWS MAINLY IN THE
60S THROUGH THUR. WED AND POSSIBLY THUR LOOK TO BE WARMEST AS 850 MB
TEMPS RISE TO NEAR 25C. SO SOME HIGHS AT OR ABOVE 90 ARE POSSIBLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 102 PM CDT FRI AUG 28 2015
MODELS ARE STILL HINTING AT THUNDERSTORM DEVELOPMENT POTENTIALLY
THIS AFTERNOON. NAM AND SREF STILL POINT TOWARD ACTIVITY NEAR
TVF/GFK BY MID AFTERNOON. HOWEVER...THE LATEST HRRR KEEPS ACTIVITY
FURTHER EAST AND SOUTH...MORE IN THE KBJI TO KFAR AREAS AROUND 00Z.
REGARDING TS...HAVE MADE ONLY MINOR CHANGES COMPARED TO PREVIOUS
FORECAST. NAM AND SREF ARE SHOWING SIGNS OF BR DEVELOPMENT LATE
TONIGHT. HAVE KEPT IT AT 5SM AROUND SUNRISE AT GFK/BJI/TVF.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...GUST
LONG TERM...GUST/MAKOWSKI
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1023 AM CDT FRI AUG 28 2015
.UPDATE...
ISSUED AT 1019 AM CDT FRI AUG 28 2015
INITIAL BAND OF STORMS DROPPING SOUTHEAST FROM MANITOBA WAS SEVERE
WITH LARGE HAIL WINKLER MB TO PEMBINA ND REGION. THESE ARE
WEAKENING. QUESTION WILL BE RE-DEVELOPMENT. UPSTREAM WIND FIELD IS
QUITE CHAOTIC AND HARD TO TELL WHERE ANY TROUGH IS LOCATED. THAT
SAID SOME LOW LEVEL BOUNDARIES PRESENT WITH THE REMAINING SHOWERS
DROPPING SOUTH COULD HELP RE-FIRE ACTIVITY THIS AFTN. HRRR AND RAP
INDICATE THAT TO OCCUR POSSIBLY JMS-FAR-BJI AREA 21Z-00Z PERIOD.
DID ADJUST POPS A BIT TO INCREASE THEM THIS MORNING AND ADJUST A
TAD FARTHER WEST AND SOUTH TODAY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT FRI AUG 28 2015
VISIBILITY ACROSS NORTHWEST MINNESOTA WILL CONTINUE TO BE VARIABLE
IN PATCHY FOG THROUGH THE PREDAWN HOURS... THOUGH ANY FOG SHOULD
DISSIPATE SHORTLY AFTER SUNRISE.
A STRONG THUNDERSTORM COMPLEX IN SOUTHERN MANITOBA THIS HOUR IS
EXPECTED TO DIMINISH IN INTENSITY AS IT BRUSHES THE U.S. BORDER
ACROSS NORTHERN CAVALIER AND KITTSON COUNTIES AROUND 12Z. ISOLATED
SHOWER AND THUNDERSTORM ACTIVITY IS THEN POSSIBLE THROUGH THE
FORENOON THROUGHOUT THE NORTH BORDER COUNTIES... SPREADING ACROSS
FAR NORTHCENTRAL MINNESOTA THROUGH THE EARLY AFTERNOON.
A SECOND ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE...STARTING IN EAST CENTRAL ND FROM MID AFTERNOON AND
SPREADING EASTWARD ALONG AN EAST-WEST ORIENTED TROF AXIS INTO
NORTHWEST MINNESOTA INTO THE EARLY EVENING. EXTENT AND SEVERITY
OF THESE STORMS WILL DEPEND ON AFTERNOON HEATING... WITH AFTERNOON
TEMPERATURES REACHING INTO THE MID 80S IN SPOTS... THUS SOME
STORMS COULD PRODUCE SMALL HAIL AND GUSTY WINDS.
LATER TONIGHT AND SATURDAY WILL SEE A RETURN TO LIGHT SOUTHERLY
FLOW AND A DRIER...MORE STABLE H5 RIDGE BUILDING IN ALOFT.
TEMPERATURES OVERALL WILL BE A BIT WARMER THAN SEASONAL NORMALS.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 AM CDT FRI AUG 28 2015
SATURDAY NIGHT AND SUUNDAY...EXPECT MORE OF THE SAME. WITH A WARM
H5 RIDGE ALOFT AND LIGHT SOUTHERLY WINDS AT THE SURFACE...EXPECT
SEASONABLY WARM AND DRY CONDITIONS WITH HIGH TEMPERATURES RANGING
FRM THEMID 80S IN CENTRAL MINNESOTA LAKES COUNTRY TO THE LOWER 90S
IN THE DEVILS LAKE BASIN.
MONDAY-THURSDAY...A VERY SUMMER-LIKE WEATHER PATTERN WILL CONTINUE
HEADING INTO THE START OF SEPTEMBER. THE UPPER RIDGE WILL FLATTEN
EARLY ON WITH SHORTWAVE ENERGY PASSING NORTH ACROSS CANADA. AN
ASSOCIATED WEAK SFC BOUNDARY COULD FIRE A FEW STORMS OFF ON
MONDAY...ALTHOUGH THE BEST UPPER SUPPORT WILL BE WELL NORTH OVER
CANADA. THIS BOUNDARY SHOULD THEN WASH OUT WITHIN PERSISTENT
SOUTHWESTERLY FLOW ALOFT. NOT VERY OPTIMISTIC ABOUT PRECIP CHANCES
LATER IN THE PERIOD...ALTHOUGH A STORM COULD NOT BE RULED OUT GIVEN
THE SOUTHWEST FLOW PATTERN/RATHER MOIST ENVIRONMENT. WARMER MID-
LEVEL TEMPS MAY ACT TO SUPPRESS CONVECTION BY WED INTO THUR AS THE
PATTERN AMPLIFIES AHEAD OF AN APPROACHING FRONT. DETAILS OUT AT THIS
RANGE ARE STILL QUITE UNCERTAIN THOUGH.
AVE HIGHS/LOWS FALL INTO THE MID TO UPPER 70S/LOW 50S DURING EARLY
SEPT...BUT HIGHS SHOULD SHOULD REACH THE 80S WITH LOWS MAINLY IN THE
60S THROUGH THUR. WED AND POSSIBLY THUR LOOK TO BE WARMEST AS 850 MB
TEMPS RISE TO NEAR 25C. SO SOME HIGHS AT OR ABOVE 90 ARE POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
UPDATED AT 355 PM CDT THU AUG 27 2015
PATCHY FOG STILL POSSIBLE IN NORTHWEST AND WEST CENTAL MINESOTA
THROUGH THE EARLY MORNING...LARGELY DISSIPATING WITH SUNRISE.
ISOLD SHOWERS AND TSTMS EXPECTED ALONG THE NORTH BORDER COUNTIES
THIS FORENOON... WITH SCT TSTMS REDEVELOPING IN THE MID AFTERNOON
ACROSS EAST CENTRAL ND AND SPREADING INTO NORTHWEST MN FROM LATE
AFTERNONN INTO EARLY EVENING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...GUST
LONG TERM...GUST/MAKOWSKI
AVIATION...JR/GUST
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
215 PM EDT FRI AUG 28 2015
.SYNOPSIS...
WARMING TREND INTO WEEKEND. ISOLATED SHOWER POSSIBLE IN
MOUNTAINS. MORE HUMID SUNDAY INTO NEXT WEEK...WITH A BETTER
CHANCE OF SHOWERS...ESPECIALLY MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
ANOTHER QUIET WEATHER DAY WITH CU FORMING OVER THE HIGHER
TERRAIN...AND ALSO IN SE OHIO. NAM CONTINUES TO SHOW SHOWERS
DEVELOPING OVER THE MOUNTAINS TODAY. DID LEAVE AN ISOLATED SHOWER
IN...BUT THINK THE HRRR HAS A BETTER SOLUTION KEEPING SHOWERS EAST
OF CWA WHERE BETTER DEVELOPED CU ARE SHOWING ON SATELLITE.
HIGH PRESSURE DRIFTS NORTHEAST TONIGHT...AND MODELS TRYING TO
SHOW SOME CLOUDS MOVING IN ACROSS THE SOUTH LATE TONIGHT AND
DRIFTING NORTH THROUGH THE DAY. ANTICIPATE VALLEY FOG BEGINNING TO
FORM...BUT MAY BE TEMPERED BY CLOUDS...ESPECIALLY ACROSS THE
SOUTH.
WITH A BIT MORE MOISTURE COMING IN SATURDAY...THINK UPSLOPE FLOW
SHOULD LEAD TO AN ISOLATED SHOWER OR TSTORM ACROSS THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
THE TRANSITION FROM WEAK UPPER RIDGING TO WEAK UPPER TROUGHING
OVER THE EASTERN U.S...WHICH WILL ALLOW AN UPPER DISTURBANCE TO
EJECT NORTHEASTWARD OUT OF THE NORTHERN GULF OF MEXICO...LOOKS TO
BE DELAYED BY ABOUT 24 HOURS. THUS...SUNDAY AFTERNOON CONVECTION
LOOKS TO BE MAINLY WIDELY SCATTERED AND OVER THE MOUNTAINS.
LOOK FOR TEMPERATURES IN THE UPPER 80S WITH MORE HUMID
CONDITIONS SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
WITH VERY WARM AND MOIST AIR IN PLACE...THE AFOREMENTIONED UPPER
DISTURBANCE LIFTING NORTHEAST ACROSS THE AREA MONDAY INTO
TUESDAY WILL BRING A BETTER CHANCE OF SHOWERS AND A STORM...ESPECIALLY
OVER THE MOUNTAINS. UPPER RIDGING WILL AGAIN BUILD OVER THE AREA
FOR THE MIDDLE AND LATER PART OF NEXT WEEK...WITH VERY WARM AND
HUMID CONDITIONS PREVAILING...BUT LITTLE RAINFALL. TEMPERATURES
WILL GENERALLY BE NEAR 90 DEGREES EACH DAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR EXPECTED TODAY WITH A 3-4KFT CU DECK AND LIGHT FLOW. RIVER
VALLEY FOG EXPECTED AGAIN TONIGHT...HOWEVER SOME UNCERTAINTY ON
JUST HOW DENSE IT WILL BECOME ACROSS THE SOUTH AS CLOUDS INCREASE
DURING THE PRE-DAWN HOURS. HAVE MVFR FOG DEVELOPING HTS-CRW THEN
DISSIPATING SHORTLY BEFORE SUNRISE. WHILE FARTHER NORTH HAVE IFR
RIVER VALLEY FOG...WITH CLOUDS FILLING IN AFTER SUNRISE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING/INTENSITY OF DENSE RIVER VALLEY FOG COULD
VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SATURDAY...
SPOTTY IFR IN RIVER VALLEY FOG POSSIBLE LATE SATURDAY INTO EARLY
SUNDAY DEPENDING ON CLOUDS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/MZ
NEAR TERM...MZ
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
133 PM EDT FRI AUG 28 2015
.SYNOPSIS...
WARMING TREND INTO WEEKEND. ISOLATED SHOWER POSSIBLE IN
MOUNTAINS. MORE HUMID SUNDAY INTO EARLY NEXT WEEK...WITH BETTER
CHANCE OF SHOWERS...ESPECIALLY LATER SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
ANOTHER QUIET WEATHER DAY WITH CU FORMING OVER THE HIGHER
TERRAIN...AND ALSO IN SE OHIO. NAM CONTINUES TO SHOW SHOWERS
DEVELOPING OVER THE MOUNTAINS TODAY. DID LEAVE AN ISOLATED SHOWER
IN...BUT THINK THE HRRR HAS A BETTER SOLUTION KEEPING SHOWERS EAST
OF CWA WHERE BETTER DEVELOPED CU ARE SHOWING ON SATELLITE.
HIGH PRESSURE DRIFTS NORTHEAST TONIGHT...AND MODELS TRYING TO
SHOW SOME CLOUDS MOVING IN ACROSS THE SOUTH LATE TONIGHT AND
DRIFTING NORTH THROUGH THE DAY. ANTICIPATE VALLEY FOG BEGINNING TO
FORM...BUT MAY BE TEMPERED BY CLOUDS...ESPECIALLY ACROSS THE
SOUTH.
WITH A BIT MORE MOISTURE COMING IN SATURDAY...THINK UPSLOPE FLOW
SHOULD LEAD TO AN ISOLATED SHOWER OR TSTORM ACROSS THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
HIGH PRESSURE AT THE SFC AND ALOFT WILL CONTINUE TO PRODUCE
SUBSIDENCE WITH DRY AIR AND FAIR WEATHER CONDITIONS. THE SFC HIGH
PRESSURE WILL MOVE EAST ALLOWING SOUTH TO SOUTHWEST FLOW INTO THE
AREA...TO INCREASE TEMPERATURES AND HUMIDITY THROUGH THE WEEKEND.
THIS SCENARIO COULD PRODUCE CONVECTION ALONG THE ELEVATED HEAT
SOURCES IN THE MOUNTAINS.
WENT CLOSER TO THE SUPER BLEND GUIDANCE FOR TEMPERATURES THROUGH
THE PERIOD. GENERALLY...EXPECT THE HOTTEST DAY ON SATURDAY WITH
TEMPERATURES REACHING THE UPPER 80S LOWLANDS RANGING INTO THE MID
70S HIGHEST ELEVATIONS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE MAIN CHANGE TO THIS PERIOD WILL BE A STRONGER UPPER
DISTURBANCE FROM THE LOWER MISSISSIPPI VALLEY LIFTING NORTHEAST
ACROSS THE AREA SUNDAY AND SUNDAY NIGHT...ENHANCING THE POTENTIAL
FOR SHOWERS AREA WIDE IN THE VERY WARM AND HUMID AIRMASS IN PLACE.
THIS PERIOD STILL SHOWS A BERMUDA HIGH OVER THE WESTERN ATLANTIC
EXPANDING WESTWARD. THIS EVOLVES INTO A WELL DEFINED UPPER RIDGE
HOLDING OVER THE WESTERN U.S. AND A BUILDING UPPER RIDGE OVER THE
WESTERN ATLANTIC...LEAVING A WEAK UPPER TROUGH BETWEEN THESE UPPER
RIDGES OVER THE EASTERN U.S.. WITH THE SURFACE HIGH CENTER ALSO
BUILDING OFF THE SOUTHEAST COAST...MOISTURE AND HEAT WILL CONTINUE
TO INCREASE ON A SOUTHERLY FLOW REGIME THIS WEEKEND INTO EARLY
NEXT WEEK. THIS WILL GIVE RISE TO A CHANCE OF MAINLY A DIURNAL
SHOWER OR THUNDERSTORM...ESPECIALLY IN THE MOUNTAINS...AND
ESPECIALLY SUNDAY AS A VERY WEAK UPPER DISTURBANCE LIFTS NORTHEAST
FROM THE GULF STATES. TEMPERATURES WILL GENERALLY APPROACH 90
DEGREES EACH DAY WITH RATHER HUMID CONDITIONS.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
VFR EXPECTED TODAY WITH A 3-4KFT CU DECK AND LIGHT FLOW. RIVER
VALLEY FOG EXPECTED AGAIN TONIGHT...HOWEVER SOME UNCERTAINTY ON
JUST HOW DENSE IT WILL BECOME ACROSS THE SOUTH AS CLOUDS INCREASE
DURING THE PRE-DAWN HOURS. HAVE MVFR FOG DEVELOPING HTS-CRW THEN
DISSIPATING SHORTLY BEFORE SUNRISE. WHILE FARTHER NORTH HAVE IFR
RIVER VALLEY FOG...WITH CLOUDS FILLING IN AFTER SUNRISE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING/INTENSITY OF DENSE RIVER VALLEY FOG COULD
VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
EDT 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M H H H H H H H M M M
EKN CONSISTENCY M H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SATURDAY...
SPOTTY IFR IN RIVER VALLEY FOG POSSIBLE LATE SATURDAY INTO EARLY
SUNDAY DEPENDING ON CLOUDS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JMV/MZ
NEAR TERM...MZ
SHORT TERM...ARJ
LONG TERM...JMV
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS NORMAN OK
309 PM CDT FRI AUG 28 2015
.DISCUSSION...
DETERMINING RAIN CHANCES TONIGHT IS THE PRIMARY FORECAST CHALLENGE
OF THE DAY.
OVERALL...SLIGHTLY LOWERED RAIN CHANCES THROUGH TONIGHT DUE TO
WEAK FORCING FOR PRODUCING RAINFALL. DID NOT GO ABOVE 20 PERCENT
IN ANY GIVEN LOCATION.
THROUGH MIDNIGHT TONIGHT...THINK A FEW LIGHT SHOWERS AND
SPRINKLES WILL CONTINUE WHERE THERE IS SOME MID LEVEL MOISTURE
CONVERGENCE...GENERALLY NEAR AN ALTUS TO NORMAN TO CHANDLER LINE.
A FEW THUNDERSTORMS ARE POSSIBLE AS WELL MAINLY NEAR AN HIGHER
INSTABILITY AXIS EXISTS FROM HOLLIS TO CLINTON TO CHEROKEE. ANY
STORM IS EXPECTED TO BE SUBSEVERE WITH PERHAPS A FEW STRONG WIND
GUSTS UP TO 50 MPH AND SOME LOCALIZED DOWNPOURS. PRECIPITATION
COVERAGE MAY DIMINISH AFTER SUNSET DUE TO THE LOSS OF DAYTIME
HEATING. RAINFALL SHOULD RAIN SPARSE AND UNDER 0.10 INCH IN MOST
LOCATIONS.
AFTER MIDNIGHT TONIGHT...A FEW SHOWERS AND PERHAPS A FEW
THUNDERSTORMS MAY CONTINUE ACROSS THE AREA...MAINLY SOUTH OF A ELK
CITY TO PONCA CITY LINE. LATEST RUC13 SUGGESTED THAT THE 850 MB
JET MAY INCREASE OVER WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA
WHICH MAY ALLOW FOR INCREASED COVERAGE OF RAIN. HOWEVER...
INSTABILITY MAY BE LACKING. THUS...KEPT 20 PERCENT CHANCES IN
THESE AREAS.
SATURDAY...OVERALL...PARTLY TO MOSTLY SUNNY AND DRY WEATHER CAN BE
EXPECTED. WOULD NOT BE COMPLETELY SURPRISED IF A STRAY SHOWER OR STORM
OCCURRED SOUTH OF A QUANAH TEXAS TO OKLAHOMA CITY TO CHANDLER
LINE...BUT DID NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
HIGHS WILL BE NEAR TO SLIGHTLY ABOVE AVERAGE...MAINLY IN THE 90S.
SATURDAY NIGHT THROUGH FRIDAY...A DRY WEATHER PATTERN IS FORECAST
WITH NEAR OR ABOVE AVERAGE TEMPERATURES. THERE ARE SOME MODEL
DIFFERENCES MAINLY IN REGARDS TO THE LOCATION AND PROGRESSION A
MID/UPPER TROUGH SOMEWHERE OVER THE SOUTHERN PLAINS OR
SOUTHEASTERN U.S. AT THIS TIME...THINK THE DEEPEST MOISTURE AND
HIGHER RAIN CHANCES WILL STAY EAST OF OKLAHOMA AND NORTH
TEXAS...BUT CONFIDENCE IS RATHER LOW.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 92 67 92 / 20 10 0 0
HOBART OK 68 96 66 96 / 20 10 10 0
WICHITA FALLS TX 74 98 68 98 / 20 10 10 10
GAGE OK 63 92 60 93 / 10 0 0 0
PONCA CITY OK 67 89 64 91 / 20 10 10 0
DURANT OK 72 94 70 95 / 20 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1113 PM EDT SAT AUG 29 2015
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL SLOWLY DRIFT TO THE EAST OVER THE
WEEKEND. MUCH WARMER WEATHER WILL MOVE INTO REGION. VERY WARM AND
INCREASINGLY HUMID WEATHER WILL CONTINUE INTO THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
STABLE STRATIFICATION HAS TAKEN PLACE ACROSS CENTRAL AND SOUTHERN
PA THIS EVENING. MEANWHILE...SLOW MOVING 5H SHEAR AXIS
ACCOMPANYING DEEP LAYER MOISTURE INCREASE AND WEAK BOUNDARY LAYER
CONVERGENCE ACROSS NORTHEAST OHIO AND NORTHWEST PA IS MAINTAINING
LIGHT SHOWER ACTIVITY LATE THIS EVENING. HRRR INDICATES SCATTERED
SHOWERS WILL MOVE OVER THE NORTHWEST MOUNTAINS FOR MUCH OF THE
OVERNIGHT WHILE MOST OF THE REST OF MY FORECAST AREA REMAINS DRY.
INCREASED POPS SLIGHTLY OVER MY NORTHWEST ZONES AS A RESULT...AND
INCLUDED SLGT CHC MENTIONS OVER NORTH CENTRAL AND NORTHEAST AS
WELL OVERNIGHT. PATCHY LIGHT RIVER VALLEY FOG EXPECTED ELSEWHERE
AS SFC DEWPOINTS SLOWLY RISE. MINS SHOULD RANGE FROM THE MID 50S
NORTH TO THE LOWER 60S SOUTHEAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SOME EARLY MORNING FOG IN THE VALLEYS - WHICH SHOULD BE OF LESSER
COVERAGE THAN SAT MORNING. THEN...THE TEMPS RISE EVEN
BETTER...ADDING ANOTHER 3-4F ONTO SAT/S MAXES.
RIDGE AT THE SFC AND ALOFT IS STARTING TO GET PRESSED A LITTLE TO
THE EAST BY AN ADVANCING UPPER TROUGH AND SLIGHT FEED OF GULF
MOISTURE. THUS...SUPPORT IN THE FORMS OF INSTABILITY AND MOISTURE
WILL BE AVAILABLE ON SUNDAY. WILL INCREASE POPS SLIGHTLY BUT KEEP
THEM MAINLY OVER THE NWRN HALF OF THE AREA AS AXIS OF THE DYING
TROUGH. SREF POPS WAY TOO AMBITIOUS. POPS FROM MOS ARE CLOSER TO
BUT STILL A LITTLE HIGHER THAN WHAT THE EXPECTED COVERAGE WILL
ALLOW FOR. WILL KEEP THEM 50 OR LESS NW AND CLOSE TO OR BELOW 20
IN THE SE HALF.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH 850HPA
TEMPS RUNNING 16-18C WHICH WILL TRANSLATE TO WELL ABOVE-NORMAL
SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR
AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT THE
PROBABILITY OF WIDESPREAD RAINFALL IS LOW.
THERE ARE A COUPLE OF INTERESTING FEATURES THAT BEAR WATCHING FOR
LATE IN THE LONG TERM PERIOD. THE FIRST IS THE REMNANTS OF
ERIKA...WHICH ARE FCST TO BE IN THE VICINITY OF THE FL/GA COAST BY
THE MIDDLE OF NEXT WEEK. AS THIS MOISTURE DIFFUSES OVER THE
SOUTHEAST U.S....SOME OF IT WILL GRADUALLY CRAWL INTO THE MID
ATLANTIC REGION. THE OTHER INTERESTING FEATURE IS A BACKDOOR COLD
FRONT THAT SOME MODELS BRING INTO THE MID-ATLANTIC STATES NEXT
THURS/FRI. THESE FEATURES COMBINED WITH THE WARM AND INCREASINGLY
HUMID AIR THAT WILL ALREADY BE IN PLACE WILL KEEP MENTION OF AT
LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY. THE LATTER
FEATURE COULD HAVE AN IMPACT ON TEMPS LATE NEXT WEEK...TAPERING
BACK TEMPS A BIT.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
SOME WEAK SHOWERS WILL MOVE ACROSS NORTHWESTERN PA BETWEEN 03 AND
06Z. VCTS IN KBFD. OTHERWISE PATCHY AREAS OF FOG MAINLY MVFR SOME
ISOLATED ARE IFR. MODELS SHOWS COULD BE SOME ISOLATED SHOWERS
BEFORE SUNRISE IN FAR WEST.
MOST MODELS SHOW HIGHEST CHANCE OF SHOWER ACROSS NORTHERN
PENNSYLVANIA SUNDAY IN THE MORNING. BY 16Z SHOWERS MOVE INTO
SOUTHWEST MOUNTAINS. USED MAINLY VCSH/VCTS TO HANDLE SHOWERS AS
THE PROBABILITIES ARE GENERALLY 20 TO 40 PERCENT. HIGHEST
PROBABILITIES OF SHOWERS/THUNDER IN NORTHWEST. KBFD WILL LIKELY
SEE A SHOWER SUNDAY.
OUTLOOK...
MON...STILL SOME SHRA/TSRA POSS.
TUE-THU...NO SIG WX EXPECTED AREAS MVFR OVERNIGHT PATCHY FOG.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
922 PM EDT SAT AUG 29 2015
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL SLOWLY DRIFT TO THE EAST OVER THE
WEEKEND. MUCH WARMER WEATHER WILL MOVE INTO REGION. VERY WARM AND
INCREASINGLY HUMID WEATHER WILL CONTINUE INTO THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
STABLE STRATIFICATION HAS TAKEN PLACE ACROSS CENTRAL AND SOUTHERN
PA THIS EVENING. MEANWHILE...SLOW MOVING 5H SHEAR AXIS
ACCOMPANYING DEEP LAYER MOISTURE INCREASE AND WEAK BOUNDARY LAYER
CONVERGENCE ACROSS NORTHEAST OHIO AND NORTHWEST PA IS MAINTAINING
LIGHT SHOWER ACTIVITY LATE THIS EVENING. HRRR INDICATES SCATTERED
SHOWERS WILL MOVE OVER THE NORTHWEST MOUNTAINS FOR MUCH OF THE
OVERNIGHT WHILE MOST OF THE REST OF MY FORECAST AREA REMAINS DRY.
INCREASED POPS SLIGHTLY OVER MY NORTHWEST ZONES AS A RESULT...AND
INCLUDED SLGT CHC MENTIONS OVER NORTH CENTRAL AND NORTHEAST AS
WELL OVERNIGHT. PATCHY LIGHT RIVER VALLEY FOG EXPECTED ELSEWHERE
AS SFC DEWPOINTS SLOWLY RISE. MINS SHOULD RANGE FROM THE MID 50S
NORTH TO THE LOWER 60S SOUTHEAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SOME EARLY MORNING FOG IN THE VALLEYS - WHICH SHOULD BE OF LESSER
COVERAGE THAN SAT MORNING. THEN...THE TEMPS RISE EVEN
BETTER...ADDING ANOTHER 3-4F ONTO SAT/S MAXES.
RIDGE AT THE SFC AND ALOFT IS STARTING TO GET PRESSED A LITTLE TO
THE EAST BY AN ADVANCING UPPER TROUGH AND SLIGHT FEED OF GULF
MOISTURE. THUS...SUPPORT IN THE FORMS OF INSTABILITY AND MOISTURE
WILL BE AVAILABLE ON SUNDAY. WILL INCREASE POPS SLIGHTLY BUT KEEP
THEM MAINLY OVER THE NWRN HALF OF THE AREA AS AXIS OF THE DYING
TROUGH. SREF POPS WAY TOO AMBITIOUS. POPS FROM MOS ARE CLOSER TO
BUT STILL A LITTLE HIGHER THAN WHAT THE EXPECTED COVERAGE WILL
ALLOW FOR. WILL KEEP THEM 50 OR LESS NW AND CLOSE TO OR BELOW 20
IN THE SE HALF.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH 850HPA
TEMPS RUNNING 16-18C WHICH WILL TRANSLATE TO WELL ABOVE-NORMAL
SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR
AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT THE
PROBABILITY OF WIDESPREAD RAINFALL IS LOW.
THERE ARE A COUPLE OF INTERESTING FEATURES THAT BEAR WATCHING FOR
LATE IN THE LONG TERM PERIOD. THE FIRST IS THE REMNANTS OF
ERIKA...WHICH ARE FCST TO BE IN THE VICINITY OF THE FL/GA COAST BY
THE MIDDLE OF NEXT WEEK. AS THIS MOISTURE DIFFUSES OVER THE
SOUTHEAST U.S....SOME OF IT WILL GRADUALLY CRAWL INTO THE MID
ATLANTIC REGION. THE OTHER INTERESTING FEATURE IS A BACKDOOR COLD
FRONT THAT SOME MODELS BRING INTO THE MID-ATLANTIC STATES NEXT
THURS/FRI. THESE FEATURES COMBINED WITH THE WARM AND INCREASINGLY
HUMID AIR THAT WILL ALREADY BE IN PLACE WILL KEEP MENTION OF AT
LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY. THE LATTER
FEATURE COULD HAVE AN IMPACT ON TEMPS LATE NEXT WEEK...TAPERING
BACK TEMPS A BIT.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
MINOR UPDATES WITH SOME SCALING BACK OF THE OVERNIGHT RAIN BASED
ON THE RADAR AND THE 3KM HRRR. SOME WEAK SHOWERS COULD REACH INTO
THE NORTHWESTERN AREAS OVERNIGHT. BUT VERY WEAK SO DID NOT PUT IN
THE TAFS. AT THIS TIME NO VCSH IN KBFD...CURRENT BEST PLACE FOR
SHOWERS AT THIS TIME.
OVERNIGHT MOSTLY PATCH GROUND FOG AND MIST....MAINLY MVFR ISOLATED
IFR.
MOST AREAS FOG BURNS OF TO HAZE AND GENERALLY ANOTHER RELATIVELY
GOOD IN SOUTH. GUIDANCE IMPLIES CHANCE SHOWERS AND THUNDERSTORMS
HIGHER ACROSS NORTHERN AND NORTHWESTERN PA. SHOWERS AND VCTS IN
KBFD MOST OF THE DAY...MENTIONED LATER 18-20Z IN SOUTH MOUNTAINS
AND CENTRAL AREAS...KJST...KAOO...KUNV AND KIPT.
KEPT RAIN OUT OF FORECAST AS LOWER PROBABILITY IN SOUTH....KMDT
AND KLNS.
OUTLOOK...
MON...MAINLY PM SHRA/TSRA POSS.
TUE-THU...NO SIG WX EXPECTED. AREAS MVFR OVERNIGHT PATCHY FOG.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DEVOIR
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...GRUMM/DANGELO
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1041 PM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 854 PM CDT SAT AUG 29 2015
INCREASED THE SKY COVER TONIGHT WHERE WE HAVE THE FOG ALREADY
MENTIONED. IN FACT THE CURRENT STRATUS IS BEING ADVECTED BACK INTO
OUR FORECAST AREA ALREADY AROUND THE STORM LAKE AND CHEROKEE IOWA
AREAS...USHERED IN BY THE SOUTH TO SOUTHEAST WINDS OFF THE
SURFACE. THEREFORE BY LATE TONIGHT AND EARLY SUNDAY...WOULD NOT BE
SURPRISED TO SEE A MESS OF FOG AND STRATUS FOR MANY AREAS ALONG
AND EAST OF THE I 29 CORRIDOR. THIS IS ALSO STRONGLY SUGGESTED BY
THE LATEST SREF LOW CLOUD PROBABILITIES...AS WELL AS THE RAP AND
HRRR.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 405 PM CDT SAT AUG 29 2015
SHOULD BE A QUIET NIGHT ACROSS THE AREA AS A SURFACE RIDGE OF HIGH
PRESSURE GRADUALLY SHIFTS SOUTHEAST. THIS WILL BRING AN INCREASING
SOUTHERLY FLOW TO THE AREA...BUT STILL REMAINING FAIRLY LIGHT
OVERNIGHT...ESPECIALLY IN NORTHWEST IOWA. WITH THE WET
GROUND...LIGHT WINDS AND MAINLY CLEAR SKIES SUSPECT THAT FOG AND
THIN LOW STRATUS WILL AGAIN DEVELOP ACROSS NORTHWEST IOWA SO WILL
INCLUDE THE THREAT FOR SHORT LIVED AND SPOTTY DENSE FOG. THE BEST
CHANCE FOR THIS WILL BE FROM ABOUT 9Z THROUGH 15Z AND SHOULD QUICKLY
ERODE MID TO LATE MORNING SIMILAR TO THIS MORNING. LOWS SHOULD
MAINLY BE FROM THE UPPER 50S TO LOWER 60S...WITH A FEW MID 60S IN
CENTRAL SD.
SOUTHERLY FLOW WILL INCREASE SUNDAY...BECOMING FAIRLY WINDY IN
CENTRAL SD DURING THE AFTERNOON. HIGHS WILL RANGE FROM THE LOWER 90S
IN CENTRAL SD TO NEAR 80 AROUND STORM LAKE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 405 PM CDT SAT AUG 29 2015
FORECAST APPEARS TO BE OVERALL FAIRLY WARM AND DRY THROUGH THE
EXTENDED AS ELONGATED UPPER LEVEL RIDGE EXTENDS FROM THE DESERT
SOUTHWEST INTO THE NORTHERN PLAINS.
ON SUNDAY NIGHT INTO MONDAY MORNING...COULD SEE SOME SHALLOW FOG
DEVELOP IN THE VALLEYS OVERNIGHT...BUT SHOULD BURN OFF FAIRLY
QUICKLY LEADING TO MOSTLY SUNNY CONDITIONS.
THERE IS A WEAK BOUNDARY THAT APPROACHES THE FORECAST AREA MONDAY
AFTERNOON INTO MONDAY NIGHT...BUT FAIRLY STRONG CAPPING INVERSION
SHOULD LIMIT SURFACE BASED CONVECTION. ELEVATED CONVECTION REMAINS
A POSSIBILITY AS THE CAPPING INVERSION IS LESS. GFS SHOWS WEAK
SHORTWAVES TRACKING ACROSS THE AREA ON TUESDAY...BUT THE ECMWF IS
SLOWER WITH THE UPPER LEVEL WAVES. FOR NOW...LEFT POPS FOCUSED
TUESDAY NIGHT.
HAVE INCREASED TEMPERATURES THROUGH MUCH OF THE WEEK WITH UPPER
LEVEL RIDGE IN PLACE. HAVE THROWN OUT GFS SOLUTION...AS IT IS WAY
TO WARM ALOFT COMPARED TO OTHER SOLUTIONS. HAVE RAISED FORECAST
HIGHS INTO THE UPPER 80S TO LOWER 90S THROUGH MUCH OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1038 PM CDT SAT AUG 29 2015
MVFR STRATUS IS BEGINNING TO STREAM NORTH TO NORTHWESTWARD ACROSS
NORTHWEST IA ALONG THE LOW LEVEL FLOW. THIS TREND WILL CONTINUE
ALL NIGHT. THEREFORE AM EXPECTING IFR TO MVFR CONDITIONS TO
PREVAIL FOR MANY AREAS GENERALLY ALONG AND EAST OF THE INTERSTATE
29 CORRIDOR. THE STRATUS COULD FIRST AFFECT KSUX SHORTLY AFTER
06Z. KFSD IS QUITE A CHALLENGE...IN THAT THEY COULD BE ON THE
EDGE OF THE NORTHWARD BUILDING STRATUS LATE TONIGHT. FOR THAT
REASON...WILL INCLUDE A TEMPO IFR GROUP FOR VISIBILITY AROUND
SUNRISE SUNDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...08
LONG TERM...
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
854 PM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 854 PM CDT SAT AUG 29 2015
INCREASED THE SKY COVER TONIGHT WHERE WE HAVE THE FOG ALREADY
MENTIONED. IN FACT THE CURRENT STRATUS IS BEING ADVECTED BACK INTO
OUR FORECAST AREA ALREADY AROUND THE STORM LAKE AND CHEROKEE IOWA
AREAS...USHERED IN BY THE SOUTH TO SOUTHEAST WINDS OFF THE
SURFACE. THEREFORE BY LATE TONIGHT AND EARLY SUNDAY...WOULD NOT BE
SURPRISED TO SEE A MESS OF FOG AND STRATUS FOR MANY AREAS ALONG
AND EAST OF THE I 29 CORRIDOR. THIS IS ALSO STRONGLY SUGGESTED BY
THE LATEST SREF LOW CLOUD PROBABILITIES...AS WELL AS THE RAP AND
HRRR.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 405 PM CDT SAT AUG 29 2015
SHOULD BE A QUIET NIGHT ACROSS THE AREA AS A SURFACE RIDGE OF HIGH
PRESSURE GRADUALLY SHIFTS SOUTHEAST. THIS WILL BRING AN INCREASING
SOUTHERLY FLOW TO THE AREA...BUT STILL REMAINING FAIRLY LIGHT
OVERNIGHT...ESPECIALLY IN NORTHWEST IOWA. WITH THE WET
GROUND...LIGHT WINDS AND MAINLY CLEAR SKIES SUSPECT THAT FOG AND
THIN LOW STRATUS WILL AGAIN DEVELOP ACROSS NORTHWEST IOWA SO WILL
INCLUDE THE THREAT FOR SHORT LIVED AND SPOTTY DENSE FOG. THE BEST
CHANCE FOR THIS WILL BE FROM ABOUT 9Z THROUGH 15Z AND SHOULD QUICKLY
ERODE MID TO LATE MORNING SIMILAR TO THIS MORNING. LOWS SHOULD
MAINLY BE FROM THE UPPER 50S TO LOWER 60S...WITH A FEW MID 60S IN
CENTRAL SD.
SOUTHERLY FLOW WILL INCREASE SUNDAY...BECOMING FAIRLY WINDY IN
CENTRAL SD DURING THE AFTERNOON. HIGHS WILL RANGE FROM THE LOWER 90S
IN CENTRAL SD TO NEAR 80 AROUND STORM LAKE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 405 PM CDT SAT AUG 29 2015
FORECAST APPEARS TO BE OVERALL FAIRLY WARM AND DRY THROUGH THE
EXTENDED AS ELONGATED UPPER LEVEL RIDGE EXTENDS FROM THE DESERT
SOUTHWEST INTO THE NORTHERN PLAINS.
ON SUNDAY NIGHT INTO MONDAY MORNING...COULD SEE SOME SHALLOW FOG
DEVELOP IN THE VALLEYS OVERNIGHT...BUT SHOULD BURN OFF FAIRLY
QUICKLY LEADING TO MOSTLY SUNNY CONDITIONS.
THERE IS A WEAK BOUNDARY THAT APPROACHES THE FORECAST AREA MONDAY
AFTERNOON INTO MONDAY NIGHT...BUT FAIRLY STRONG CAPPING INVERSION
SHOULD LIMIT SURFACE BASED CONVECTION. ELEVATED CONVECTION REMAINS
A POSSIBILITY AS THE CAPPING INVERSION IS LESS. GFS SHOWS WEAK
SHORTWAVES TRACKING ACROSS THE AREA ON TUESDAY...BUT THE ECMWF IS
SLOWER WITH THE UPPER LEVEL WAVES. FOR NOW...LEFT POPS FOCUSED
TUESDAY NIGHT.
HAVE INCREASED TEMPERATURES THROUGH MUCH OF THE WEEK WITH UPPER
LEVEL RIDGE IN PLACE. HAVE THROWN OUT GFS SOLUTION...AS IT IS WAY
TO WARM ALOFT COMPARED TO OTHER SOLUTIONS. HAVE RAISED FORECAST
HIGHS INTO THE UPPER 80S TO LOWER 90S THROUGH MUCH OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1249 PM CDT SAT AUG 29 2015
IFR CONDITIONS RAPIDLY IMPROVING ACROSS NORTHWEST IOWA WHICH
SHOULD BE THE TREND THROUGH 20Z. SURFACE RIDGE GRADUALLY PUSHES
EAST TODAY WITH SOUTHERLY FLOW DEVELOPING...BECOMING A BIT BREEZY
IN CENTRAL SD SHORTLY AFTER SUNRISE ON SUNDAY MORNING. NORTHWEST
IOWA WILL STILL SEE SOME WEAK FLOW AND A DECENT INVERSION
OVERNIGHT SO ANOTHER THREAT FOR FOG AND STRATUS LATE TONIGHT AND
IN THE MORNING...ESPECIALLY AT KSUX FROM ABOUT 8Z THROUGH 15Z.
KFSD WILL ALSO SEE THE THREAT BUT WILL BE ON THE EDGE AND HAVE NOT
INCLUDED ANY IFR CONDITIONS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...08
LONG TERM...
AVIATION...08
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1227 PM CDT FRI AUG 28 2015
.AVIATION...
SCATTERED THUNDERSTORMS WILL BE POSSIBLE AT ALL TAF SITES THIS
AFTERNOON AND EARLY EVENING BUT CONFIDENCE IN COVERAGE IS TOO LOW
TO MENTION IN THE TAF AT THE MOMENT. THESE STORMS WILL RESULT FROM
A COLD FRONT TO MOVE THROUGH THIS EVENING. ALTHOUGH WINDS WILL
SHIFT TO THE NORTH...SPEEDS ARE EXPECTED TO REMAIN LIGHT.
&&
PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 28 2015/
SHORT TERM...
UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING
IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE-
AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS
TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS
EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD
ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z.
ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION...
SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE
FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL
FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING
CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN
ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE
SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON
ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF
THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL
MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED
AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING
THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE
LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE
SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE
EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL
EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING
SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING
PLAINS THROUGHOUT THE SHORT TERM PERIOD.
STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION
MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE
POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE
REGION.
BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO
NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN
YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX
PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE
LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S.
LONG TERM...
A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN
OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK
WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE
NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS
AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP
TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER
ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE
NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS.
MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM
AND HAVE KEPT MENTION OUT ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 89 61 91 / 20 10 0 0
TULIA 62 91 61 91 / 20 10 0 0
PLAINVIEW 63 91 63 91 / 30 10 0 0
LEVELLAND 64 91 64 92 / 30 10 10 0
LUBBOCK 65 92 65 93 / 30 10 0 0
DENVER CITY 63 91 63 92 / 30 10 0 0
BROWNFIELD 65 92 65 93 / 30 10 0 0
CHILDRESS 69 96 68 97 / 20 10 0 0
SPUR 69 94 67 96 / 20 10 10 0
ASPERMONT 72 97 70 99 / 10 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01/99/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
712 AM CDT FRI AUG 28 2015
.UPDATE...
LATEST RADAR TRENDS SHOWED THE DEVELOPMENT OF ISOLATED TO
SCATTERED LIGHT SHOWERS ACROSS THE ROLLING PLAINS THIS
MORNING..AHEAD OF THE COLD FRONT. HAVE ADDED CHANCE POPS ACROSS
THE AFOREMENTIONED AREA.
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT FRI AUG 28 2015/
AVIATION...
ISOLATED TO SCATTERED -SHRA AND -TSRA HAVE DEVELOPED NORTH OF
KCDS...WITH ISOLATED -SHRA DEVELOP CLOSE TO KCDS EARLY THIS
MORNING ALONG A COLD FRONT HAVE THEREFORE INSERTED A TEMPO FOR
-TSRA FOR A FEW HOURS THIS MORNING. ADDITIONAL DEVELOPMENT IS
POSSIBLE AT KLBB AND KPVW LATER THIS AFTERNOON AND
EVENING...THOUGH CONFIDENCE IS NOT HIGH ENOUGH TO INSERT A MENTION
AT THIS TIME. WILL OF COURSE AMEND AS NECESSARY. OTHERWISE OUTSIDE
OF ANY -SHRA/-TSRA...VFR CONDITIONS ARE EXPECTED AS SCT-BKN CLOUD
DECKS PASS OVERHEAD.
PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 28 2015/
SHORT TERM...
UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING
IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE-
AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS
TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS
EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD
ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z.
ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION...
SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE
FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL
FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING
CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN
ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE
SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON
ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF
THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL
MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED
AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING
THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE
LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE
SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE
EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL
EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING
SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING
PLAINS THROUGHOUT THE SHORT TERM PERIOD.
STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION
MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE
POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE
REGION.
BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO
NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN
YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX
PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE
LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S.
LONG TERM...
A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN
OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK
WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE
NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS
AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP
TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER
ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE
NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS.
MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM
AND HAVE KEPT MENTION OUT ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 87 61 89 61 / 20 20 10 0
TULIA 90 62 91 61 / 30 20 10 0
PLAINVIEW 89 63 91 63 / 30 30 10 0
LEVELLAND 93 64 91 64 / 30 30 10 10
LUBBOCK 94 65 92 65 / 30 30 10 0
DENVER CITY 93 63 91 63 / 20 30 10 0
BROWNFIELD 94 65 92 65 / 20 30 10 0
CHILDRESS 96 69 96 68 / 30 20 10 0
SPUR 98 69 94 67 / 20 20 10 10
ASPERMONT 100 72 97 70 / 20 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
629 AM CDT FRI AUG 28 2015
.AVIATION...
ISOLATED TO SCATTERED -SHRA AND -TSRA HAVE DEVELOPED NORTH OF
KCDS...WITH ISOLATED -SHRA DEVELOP CLOSE TO KCDS EARLY THIS
MORNING ALONG A COLD FRONT HAVE THEREFORE INSERTED A TEMPO FOR
-TSRA FOR A FEW HOURS THIS MORNING. ADDITIONAL DEVELOPMENT IS
POSSIBLE AT KLBB AND KPVW LATER THIS AFTERNOON AND
EVENING...THOUGH CONFIDENCE IS NOT HIGH ENOUGH TO INSERT A MENTION
AT THIS TIME. WILL OF COURSE AMEND AS NECESSARY. OTHERWISE OUTSIDE
OF ANY -SHRA/-TSRA...VFR CONDITIONS ARE EXPECTED AS SCT-BKN CLOUD
DECKS PASS OVERHEAD.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 28 2015/
SHORT TERM...
UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING
IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE-
AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS
TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS
EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD
ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z.
ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION...
SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE
FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL
FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING
CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN
ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE
SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON
ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF
THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL
MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED
AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING
THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE
LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE
SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE
EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL
EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING
SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING
PLAINS THROUGHOUT THE SHORT TERM PERIOD.
STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION
MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE
POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE
REGION.
BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO
NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN
YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX
PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE
LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S.
LONG TERM...
A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN
OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK
WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE
NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS
AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP
TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER
ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE
NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS.
MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM
AND HAVE KEPT MENTION OUT ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 87 61 89 61 / 20 20 10 0
TULIA 90 62 91 61 / 30 20 10 0
PLAINVIEW 89 63 91 63 / 30 30 10 0
LEVELLAND 93 64 91 64 / 30 30 10 10
LUBBOCK 94 65 92 65 / 30 30 10 0
DENVER CITY 93 63 91 63 / 20 30 10 0
BROWNFIELD 94 65 92 65 / 20 30 10 0
CHILDRESS 96 69 96 68 / 30 20 10 0
SPUR 98 69 94 67 / 20 20 10 10
ASPERMONT 100 72 97 70 / 10 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
331 AM CDT FRI AUG 28 2015
.SHORT TERM...
UA RIDGE CENTERED TO OUR WEST HAS FLATTENED OUT A BIT THUS RESULTING
IN WNW FLOW ALOFT PREVAILING ACROSS THE SOUTHERN PLAINS. THIS DE-
AMPLIFICATION OF THE UA RIDGE IS DUE TO AN UA SHORTWAVE THAT HAS
TRACKED ENE FROM THE ROCKIES TO ACROSS THE CENTRAL/NORTHERN PLAINS
EARLY THIS MORNING. ITS ASSOCIATED COLD FRONT HAS BEEN SAGGING SWRD
ACROSS THE TX PANHANDLE AND HAS MOVED SOUTH OF KAMA AS OF 08Z.
ALTHOUGH THE BEST LARGE SCALE ASCENT IS WELL NORTH OF THE REGION...
SCATTERED CONVECTION HAS MANAGED TO DEVELOP IN THE WAKE OF THE
FRONT ACROSS THE TX PANHANDLE...COURTESY OF ADEQUATE FRONTOGENETICAL
FORCING. NOT ONLY ARE MODEL SOLUTIONS HAVING DIFFICULTY IN SHOWING
CONSENSUS WRT TO THE TIMING OF THE FRONT /IMPINGING ON THE NRN
ZONES ANYWHERE FROM 12-18Z/ BUT ARE ALSO HAVING DIFFICULTY IN THE
SPATIAL EXTENT OF PRECIP...THUS MAKING IT HARD TO HANG YOUR HAT ON
ANY ONE PARTICULAR SOLUTION. NONETHELESS...IF THE CURRENT SPEED OF
THE FRONT DOES NOT SLOW DOWN MUCH...IT APPEARS THAT THE FRONT WILL
MOVE ACROSS THE NRN ZONES AN HOUR OR SO BEFORE SUNRISE /AS HINTED
AT BY THE RAP SOLUTION/ AND THEREFORE PROGGED TO GET HUNG UP DURING
THE DAYTIME /ORIENTED FROM SW TO NE/...HENCE NOT QUITE CLEARING THE
LOW ROLLING PLAINS. SOLUTIONS DO EXHIBIT PRECIP ORIENTED FROM THE
SWRN ZONES TO THE NERN ZONES ALONG THE FRONT...THOUGH AS STATE
EARLIER...SOME SOLUTIONS ARE A BIT MORE BULLISH IN ITS SPATIAL
EXTENT AND QPF AMOUNTS. WILL THEREFORE HOLD ON TO BEST POPS BEING
SHOWN FROM SW TO NE...WITH LOWEST POPS ACROSS THE LOW ROLLING
PLAINS THROUGHOUT THE SHORT TERM PERIOD.
STEEPENING LAPSE RATES THIS AFTN COUPLED WITH DAYTIME DESTABILIZATION
MAY RESULT IN A FEW STORMS GENERATING BRIEF WIND GUSTS...BUT SEVERE
POTENTIAL APPEARS LOW GIVEN BEST UL SUPPORT WILL BE NORTH OF THE
REGION.
BEING THAT THE COLD FRONT IS NOT TERRIBLY STRONG /AS 850 MB TEMPS DO
NOT DROP TERRIBLY LOW/ IT WILL STILL BE A FEW DEGREES COOLER THAN
YESTERDAY WITH HIGHS RANGING FROM THE UPPER 80S ACROSS THE FAR SW TX
PANHANDLE TO THE UPPER 90S TO LOWER 100 DEGREE READINGS ACROSS THE
LOW ROLLING PLAINS. OVERNIGHT LOWS WILL BE IN THE 60S AND 70S.
.LONG TERM...
A FAIRLY QUIET PERIOD COMING UP. THE LONG WAVE UPPER AIR PATTERN
OVER THE CONUS WILL REMAIN GENERALLY THE SAME THROUGH NEXT WEEK
WITH A TROUGH OVER THE WEST AND RIDGING FROM THE SRN PLAINS TO THE
NORTHEAST. HOWEVER...WEAKNESSES IN THE RIDGE WILL LEAVE HEIGHTS
AND THICKNESSES OVER THE AREA OF A MAGNITUDE THAT SHOULD KEEP
TEMPERATURES FROM GETTING TOO FAR OVER SEASONAL NORMS. ONLY OTHER
ISSUE IS POTENTIAL FOR GENERALLY AFTN AND EVENING PRECIP IN THE
NWRN COUNTIES VCNTY OF SFC TROUGH AND LOW LEVEL INSTABILITY AXIS.
MONDAY AND TUESDAY WOULD BE FAVORED. CONFIDENCE REMAINS LOW ATTM
AND HAVE KEPT MENTION OUT ATTM.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 87 61 89 61 / 20 20 10 0
TULIA 90 62 91 61 / 30 20 10 0
PLAINVIEW 89 63 91 63 / 30 30 10 0
LEVELLAND 93 64 91 64 / 30 30 10 10
LUBBOCK 94 65 92 65 / 30 30 10 0
DENVER CITY 93 63 91 63 / 20 30 10 0
BROWNFIELD 94 65 92 65 / 20 30 10 0
CHILDRESS 96 69 96 68 / 30 20 10 0
SPUR 98 69 94 67 / 20 20 10 10
ASPERMONT 100 72 97 70 / 10 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/07
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
845 PM CDT SAT AUG 29 2015
.UPDATE...
CLOUDS WILL REMAIN LOCKED IN OVERNIGHT UNDER VERY WEAK FLOW AND
VERY MOIST BOUNDARY LAYER CONDITIONS. THE MAIN QUESTION IS WHETHER
WE/LL SEE DENSE FOG DEVELOP. GUIDANCE SUGGEST THE BEST CHANCE FOR
DENSE FOG WILL BE THROUGHOUT THE COUNTIES BORDERING LAKE MICHIGAN.
THE NEARSHORE WATERS ARE QUITE COOL DUE TO SOME UPWELLING THAT
OCCURRED EARLIER IN THE WEEK AND THIS IS LIKELY RESULTING IN THE
VERY LOW CLOUD DECKS AND REDUCED VSBYS THERE. THE ATWATER BUOY OFF
OF MILWAUKEE IS REPORTING A 49F WATER TEMP. THE PERSISTENT STRATUS
MAY KEEP THE FOG FROM GETTING DENSE...BUT WILL KEEP AN EYE ON IT
AND POST A DENSE FOG ADVISORY LATER IF NEEDED.
OTHERWISE...TEMPS WON/T FALL TOO HARD TONIGHT WITH THE CLOUDS AND
ELEVATED DEW POINTS. WE SHOULD SEE SOME CLEARING LATER IN THE
MORNING ON SUNDAY AS THE SUN HELPS TO MIX OUT THE LOW LEVEL
MOISTURE.
&&
.AVIATION/06Z TAFS/...
WE SHOULD SEE IFR AND LIFR CONDITIONS EXPAND THROUGH THE NIGHT
DUE TO WEAK LOW LEVEL FLOW AND VERY HIGH BOUNDARY LAYER MOISTURE.
KMKE COULD SEE LIFR CIGS/VSBYS DUE TO THE PROXIMITY OF THE LAKE
AND ITS INFLUENCE WITHIN THE LIGHT FLOW REGIME. CONDITIONS SHOULD
QUICKLY IMPROVE BY 14-16Z SUNDAY MORNING. WINDS WILL BE LIGHT
THROUGH THE TAF PERIOD.
&&
.MARINE...
WILL CONTINUE THE MARINE DENSE FOG ADVISORY DUE TO THE COOL WATERS
WITHIN THE NEARSHORE WATERS COMBINING WITH THE ELEVATED DEW
POINTS. CONDITIONS SHOULD IMPROVE BY MID TO LATE MORNING ON
SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 316 PM CDT SAT AUG 29 2015/
SHORT TERM...
TONIGHT - CONFIDENCE...MEDIUM
MID LEVEL TROUGH AXIS SHIFTING SOUTHEAST OF WI. MEANWHILE THE LOW
LEVELS REMAIN MOIST WITH LITTLE STIRRING OR CHANGE OF AIRMASS. A
WEAK INVERTED TROUGH EXTENDS INTO WI. WIDESPREAD STRATUS HAS A
PRETTY FIRM GRIP ON CENTRAL AND SOUTHERN WI. SOME BREAKS AND THIN
SPOTS HAVE TRIED TO TAKE SHAPE WITHIN SUBSIDENCE REGION OF EXITING
SHORTWAVE HOWEVER THIS HAS BEEN SLOW TO EVOLVE WITH OVC CONDITIONS
BEING PREVALENT. EXPECTING THIS REGIME TO CHANGE LITTLE INTO THE
OVERNIGHT HOURS AS THE COLUMN REMAINS FREE OF WIND IN THE SURFACE-
850 MILLIBAR LAYER. EXPECT FOG TO BECOME A BIT THICKER AS THE NIGHT
WEARS ON BUT CONFIDENCE NOT GREAT THAT WIDESPREAD DENSE FOG WILL
BECOME AN ISSUE DUE TO THE ONGOING STRATUS FIELD. ANY BREAKS THAT
EVOLVE WOULD EXPECT STRATUS/FOG TO FILL RIGHT BACK IN. WITH THE
CLOUD COVER LITTLE TEMP DROPOFF EXPECTED.
SUNDAY - CONFIDENCE...MEDIUM
MID LEVEL RIDGING TAKES HOLD WITH SURFACE HIGH DOMINATING IN THE LOW
LEVELS. AGAIN NOT MUCH STIRRING SO EROSION OF MORNING FOG/STRATUS MAY
BE A SLOW PROCESS. 925 THERMAL TROUGH EASES A BIT WITH WINDS TURNING
MORE SW AND 850 SHOWS SOME WARMING AS WELL. SO ONCE THE SUN BREAKS
THROUGH EXPECT TEMPS TO GET BACK INTO THE 70S WITH PERHAPS AN 80 OR
TWO IN WESTERN CWA WHERE LINGERING STRATUS LIKELY TO ERODE SOONEST.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE HIGH.
THE UPPER RIDGE OVER THE PLAINS WILL ROLL OVER INTO THE GREAT
LAKES FOR SUN NT AND MON. THE SFC HIGH WILL MOVE SLIGHTLY TO THE
EAST OF THE REGION WITH A SLY FLOW DEVELOPING. 925 MB TEMPS WILL
RISE TO 23-24C BY LATE AFTERNOON ON MON WHICH YIELDS HIGHS IN THE
MID TO UPPER 80S AWAY FROM THE LAKE BREEZE. THE UPPER RIDGE WILL
FLATTEN AND MOVE TO THE MID ATLANTIC STATES FOR TUE WITH A SWLY
FLOW ALOFT FROM THE WRN USA INTO THE NRN GREAT LAKES. IT APPEARS
ANY EMBEDDED WEAK SHORTWAVE TROUGHS WILL REMAIN TO THE WEST SO THE
DRY FCST CONTINUES. HIGH TEMPS MID TO UPPER 80S WILL CONTINUE
EXCEPT NEAR LAKE MI.
LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE
MEDIUM.
THE MEAN UPPER TROUGH WILL REMAIN OVER WRN CANADA AND THE PACIFIC
NW WITH A BROAD RIDGE OVER MUCH OF THE CENTRAL AND ERN USA. WEAK
SHORTWAVE TROUGHS HOWEVER WILL FLATTEN THE RIDGE AT TIMES AND
BRING SLIGHT CHANCES OF TSTORMS TO THE REGION FROM WED-SAT. VERY
WARM AND HUMID CONDITIONS WILL CONTINUE.
AVIATION/00Z TAFS/...VERY WEAK 925/850 FLOW THROUGH TONIGHT AND
INTO EARLY SUNDAY AS WELL. SUBSIDENCE WITH PASSING SHORTWAVE NOT
DOING MUCH TO ERODE THE CLOUD COVER. RAP SOUNDINGS LOOK TO DRY
THINGS OUT LATER TODAY AND THIS EVENING BUT THAT CONTINUES TO LOOK
OPTIMISTIC. LEANING MORE TOWARDS THE METMOS GUID GIVEN PRESENT VSBL
IMAGERY/SFC OBS. STRATUS LIKELY TO KEEP VSBYS FROM GETTING
WIDESPREAD DENSE THOUGH LOW LEVELS ARE MORE MOIST DUE TO THE RECENT
RAINS. BUT STILL EXPECTING A GOOD DEAL OF LIFR CONDITIONS. THE
WIDESPREAD STRATUS/FOG IS LIKELY TO PERSIST INTO SUNDAY MORNING.
THEN AS SOME WEAK WAA TAKES HOLD EXPECTING SOME EROSION TO TAKE
PLACE WITH GRADUALLY IMPROVING CIGS/VSBYS AS THE DAY WEARS ON.
MARINE...WITH A LIGHT WIND REGIME AND A MOIST AIRMASS REMAINING IN
PLACE HAVE HOISTED A DENSE FOG ADVISORY UNTIL 10 AM SUNDAY. FOG
WILL BE REMAIN POSSIBLE AT TIMES OVER LAKE MI FOR THE NEW WEEK
DUE TO A HUMID AND STAGNANT AIRMASS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 10 AM CDT SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...DAVIS
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
457 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL LIFT NORTH THROUGH GEORGIA
AND THE CAROLINAS THROUGH TONIGHT. ON THE PERIPHERY OF ATLANTIC HIGH
PRESSURE...A WEAK TROUGH OF LOW PRESSURE WILL MEANDER OVER THE
SOUTHEAST MOST OF THIS WEEK. LATE THIS WEEK INTO NEXT WEEKEND...LOW
PRESSURE WILL DEVELOP OVER THE ATLANTIC WHILE WEAK INLAND HIGH
PRESSURE EXPANDS SOUTH AND EAST INTO THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...QUITE A SURGE OF DEEP MOISTURE HAS BEEN ONGOING ACROSS SE
GEORGIA OVERNIGHT AS LOW LEVEL FLOW HAS VEERED TO SE OFF THE GEORGIA
COASTAL ENHANCING STRONG CONVERGENCE ALONG THE SAVANNAH RIVER AND
PUSHING SHOWERS AND TSTMS NORTH INTO SOUTHERN AND COASTAL SOUTH
CAROLINA. A CLUSTER OF INTENSE RAINFALL PASSING THROUGH EASTERN
CHATHAM COUNTY BUT IT SHOULD MOVE ALONG AND PERHAPS WEAKENING
JUST A BIT AS IT SHIFTS INTO JASPER AND BEAUFORT COUNTIES. BY
DAWN...CHANCE POPS REACHING INTO OUR FAR NW ZONES WHILE LIKELY OR
EVEN HIGHER CHANCES SOUTH OF I-16 INTO COASTAL SOUTH CAROLINA.
THROUGH TONIGHT...AN ANOMALOUS MID AND UPPER LOW OVER THE WESTERN
FLORIDA PANHANDLE AT DAYBREAK WILL LIFT NE AND GRADUALLY OPEN
INTO A WAVE AS IT HEADS TOWARD THE SOUTHERN APPALACHIANS. THIS
FEATURE WILL RESULT IN AN STEADY INFLUX OF DEEP MOISTURE WITH
PWATS ABOVE 2 INCHES INTO SOUTHERN SC AND SE GA. IT ALSO ARRIVES
WITH DECENT FORCING FOR ASCENT IN RESPONSE TO A 40-45 JET MAX AT
500 MB AND STEADY UPPER DIVERGENCE AS IT PASSES OVERHEAD. THIS
WILL CAUSE AT LEAST SCATTERED TO NUMEROUS COVERAGE OF RAINFALL
WITH POCKETS OF DEEP CONVECTION LIKELY ALONG WITH OCCASIONAL
DOWNPOURS.
A COMPLEX MESOSCALE WITH UNSEASONABLY STRONG LOW LEVEL MOISTURE
GRADIENTS LAST NIGHT HAS GIVEN WAY TO RAINS MARCHING NORTH WITH SOME
THUNDER ALONG COASTAL AND SOUTHERN ZONES. THERE SHOULD BE A GOOD
POTENTIAL FOR LOCALLY HEAVY RAINFALL TODAY...THE GFS AND RECENTLY
HIGH RESOLUTION OUTPUTS FROM BOTH THE HRRR AND NSSL ARW MODELS
SUGGEST THERE COULD ALSO BE A LULL IN HEAVY RAIN POTENTIAL NORTH
OF THE SAVANNAH RIVER THIS AFTERNOON BETWEEN TSTMS DEVELOPING
AHEAD OF THE EJECTING LOW ACROSS EAST CENTRAL GEORGIA/CSRA AND
COASTAL CONVERGENCE CONTINUING TO THE SOUTH OF THE SAVANNAH
RIVER. MODELS SUGGEST STEEPENING INLAND LAPSE RATES ALONG WITH AT
LEAST 25 KT OF 0-6 KM BULK SHEAR ACROSS OUR INLAND ZONES THIS
AFTERNOON AND EVENING. INLAND AREAS TO WEST OF I-95 COULD SEE A
WINDOW FOR ISOLATED STRONG TO SEVERE TSTMS AS UPPER LEVEL FORCING
INCREASES AHEAD OF VERY WELL DEFINED DRIER SLOT BETWEEN 850 MB AND
500 MB. WOULD NOT BE SURPRISED TO SEE CONVECTION ORGANIZE LATER
TODAY TO THE WEST OF I-95 AND WE WILL HAVE TO MONITOR FOR ISOLATED
SEVERE WEATHER POTENTIAL.
TONIGHT...CONTINUED COMPLEXITIES AS THE UPPER LOW EJECTS BY AND
DRYING MID LEVELS EVENTUALLY SHUT DOWN RAINS ALONG AND WEST OF
I-95 BUT ATTENTION TURNS TO HEAVY RAIN POTENTIAL ALONG COASTAL
SOUTH CAROLINA AFTER MIDNIGHT AS STRONG UPPER DIVERGENCE WILL
ENHANCE LIFT WHILE DEEP LAYERED MOISTURE AND SIGNIFICANT LOW LEVEL
MOISTURE CONVERGENCE ENHANCES CONVECTIVE RAINS. WE RAMP POPS UP
TO CATEGORICAL ALONG THE CENTRAL SOUTH CAROLINA COAST LATE.
LOCALLY HEAVY RAINS...PERHAPS ISOLATED EXCESSIVE RAINFALL MAY
OCCUR ALONG CHARLESTON COUNTY IF THE LATEST MODEL GUIDANCE PANS
OUT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY MORNING...THE UPPER TROUGH AND ASSOCIATED FORCING FOR ASCENT
WILL HAVE ADVANCED NORTH/NORTHEAST OF THE REGION. HOWEVER...FOCUSED
LOW/MID LEVEL MOISTURE TRANSPORT AND AN ASSOCIATED PLUME OF PWATS 2
TO 2.25 INCHES WILL CONTINUE TO PUSH ONSHORE ESPECIALLY INTO SOUTH
CAROLINA COUNTIES. GIVEN ABOVE-AVERAGE MODEL AGREEMENT REGARDING
THIS SCENARIO...MONDAY MORNING FEATURES LIKELY/CATEGORICAL POPS
ALONG/EAST OF I-95...HIGHEST INTO SC COUNTIES INCLUDING THE
CHARLESTON TRI-COUNTY REGION. GIVEN ELEVATED PWATS AND HIGH
PRECIPITATION EFFICIENCY...INTRODUCED A MENTION OF HEAVY RAIN INTO
AREAS ALONG/EAST OF I-95. ALSO...AN ELEVATED HIGH TIDE WILL OCCUR
BETWEEN 900 AND 1100 AM...AND IF/WHERE HEAVY RAIN IS FALLING WITHIN
COASTAL COUNTIES LOCALIZED FLOODING WILL BE POSSIBLE. THIS POTENTIAL
INCLUDED DOWNTOWN CHARLESTON.
MONDAY AFTERNOON...POPS BECOME LESS WELL DEFINED DUE TO THE UNKNOWN
IMPACT OF MORNING SHOWERS/THUNDERSTORMS AND DUE TO THE POTENTIAL FOR
SUBTLE DRYING TO OCCUR ACROSS NORTHERN/INLAND COUNTIES. EARLY
AFTERNOON POPS ARE TAPERED FROM LIKELY NEAR THE COAST TO CHANCE
INLAND.
OTHERWISE...DUE TO CLOUDS AND PRECIPITATION...MONDAY HIGH TEMPS IN
THE LOWER/MID 80S SHOULD BE COMMON...SLIGHTLY BELOW NORMAL FOR LATE
AUGUST.
MONDAY NIGHT...A POOL OF DEEP MOISTURE WILL REMAIN FOCUSED NEAR THE
COAST AND OVER COASTAL WATERS. INLAND POPS DECREASE FROM CHANCE TO
SLIGHT CHANCE WITH TIME INLAND...WHILE POPS NEAR THE COAST REMAIN IN
THE 50-60 PERCENT RANGE...HIGHEST OVER CENTRAL/SOUTHERN COASTAL
COUNTIES. LOCALLY EXCESSIVE RAINFALL WILL REMAIN POSSIBLE NEAR THE
COAST.
THE SCENARIO APPEARS SIMILAR TUESDAY THROUGH WEDNESDAY. WHILE
SLIGHTLY DRIER AIR COULD INFILTRATE NORTHERN/INLAND COUNTIES...A
POOL OF ENHANCED MOISTURE WILL REMAIN TRAPPED BENEATH A BUILDING
UPPER RIDGE...ESPECIALLY OVER SOUTHERN COUNTIES AND ACROSS ADJACENT
COASTAL WATERS. POPS ARE DISTRIBUTED ACCORDINGLY...WITH
HIGHEST/LIKELY POPS ACROSS SOUTHERN COUNTIES. HIGH PWATS AND WEAK
STEERING FLOW WILL CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY
HEAVY RAINFALL. TEMPS WILL DEPEND ON CLOUD/PRECIPITATION COVERAGE.
HIGHS IN THE MID 80S WILL REMAIN COMMON BOTH DAYS. HOWEVER...
TEMPERATURES COULD REMAIN IN THE LOWER 80S IF/WHERE CLOUDS/SHOWERS
PERSIST...WHILE TEMPERATURES COULD RECOVER INTO THE UPPER 80S WHERE
PRECIPITATION COVERAGE IS REDUCED...ESPECIALLY INLAND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
UNTIL LATE WEEK...SUFFICIENT MOISTURE WILL PERSIST BENEATH AN UPPER
RIDGE TO SUPPORT AT LEAST SCATTERED SHOWERS/THUNDERSTORMS ESPECIALLY
DURING THE MIDDAY/EVENING HOURS AND ALONG THE COAST/OVER ADJACENT
COASTAL WATERS DURING THE LATE NIGHT/EARLY MORNING HOURS. LATE THIS
WEEK INTO NEXT WEEKEND OFF THE MID ATLANTIC COAST NEAR 37N/70W...AN
AMPLIFYING UPPER TROUGH WILL PROMOTE SURFACE CYCLOGENESIS...AND THIS
SYSTEM WILL EVOLVE INTO DEEP LAYERED/CUT-OFF LOW PRESSURE. THIS
SYSTEM WILL DRIVE THE UPPER RIDGE WELL SOUTH OF THE REGION...BUT THE
IMPACTS ON SENSIBLE WEATHER REMAIN UNCERTAIN. IF THE ATLANTIC TROUGH
PHASES WITH THE UPPER LOW ALONG THE GULF COAST...AN UNSETTLED
PATTERN COULD DEVELOP OVER THE REGION. HOWEVER...IF THE SYSTEMS
REMAIN SEPARATE...SOMEWHAT DRIER AIR COULD SPREAD INTO THE REGION
FROM THE NORTH/NORTHWEST. THUS...POPS REMAIN PRETTY CLOSE TO
NORMAL. TEMPERATURES SHOULD REMAIN CLOSE TO NORMAL THROUGH THE
PERIOD...AND FORECAST TEMPERATURES REMAIN BELOW 90F THROUGH NEXT
WEEKEND. HOWEVER...THE PROBABILITY FOR WARMER TEMPS INTO THE LOWER
90S COULD INCREASE LATE WEEK INTO NEXT WEEKEND ESPECIALLY IF DRIER
AIR CIRCULATES INTO THE REGION.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THE OVERALL PICTURE IS A SWING TO GRADUALLY DETERIORATING
CONDITIONS WITH ARRIVAL OF SHOWERS AND STORMS BEFORE DAWN AT
BOTH KSAV AND KCHS. SHOWERS AND A FEW STORMS NUMEROUS THROUGH THE
AFTERNOON HOURS AS DEEP MOISTURE AND DYNAMIC LIFTING PROCESSES
RESULTING IN WIDESPREAD COVERAGE. PERIODS OF IFR CONDITIONS ARE
POSSIBLE DURING BOUTS OF HEAVIER RAINS AND/OR TSTMS TODAY...
ESPECIALLY FROM AROUND MIDDAY TO EARLY EVENING.
EXTENDED AVIATION OUTLOOK THROUGH THURSDAY...PERIODS OF FLIGHT
RESTRICTIONS APPEAR LIKELY THROUGH EARLY WEEK...ESPECIALLY IN
SHOWERS/THUNDERSTORMS. VFR SHOULD BECOME MORE COMMON MID TO LATE
WEEK.
&&
.MARINE...
ONSHORE FLOW WILL INCREASE ACROSS GEORGIA WATERS LATER TODAY AND
TONIGHT...PERHAPS 15-20 KT WITH SOME HIGHER GUSTS POSSIBLE FROM
GRAYS REEF AND BEYOND. THIS COULD ASSIST SEAS BUILDING TO SMALL
CRAFT ADVISORY LEVELS OVER GEORGIA WATERS FROM 20-60 NM LATER
TONIGHT. WIDESPREAD RAINS AND OCCASIONAL TSTMS OVER THE WATERS
THROUGH TONIGHT WILL LOWER VSBYS BELOW 3 NM AT TIMES AND PRODUCE
LOCALLY GUSTY WINDS...ESPECIALLY TONIGHT. WE HAVE HELD OFF ON
ISSUING AN SCA FOR OUTER WATERS JUST YET UNTIL WE GET A BETTER
HANDLE ON CONVECTION PATTERNS WHICH MAY DISRUPT WINDS BUT
LOCALLY ENHANCE WAVES.
PERSISTENT SE WINDS COULD USHER A 6 FT SWELL INTO GA COASTAL WATERS
BEYOND 20-40 NM MONDAY. THIS SCENARIO REMAINS UNCERTAIN...THUS WILL
NOT YET RAISE A SMALL CRAFT ADVISORY. OTHERWISE...SOUTHEAST WINDS
SHOULD REMAIN CAPPED AT 15-20 KT AND SEAS SHOULD REMAIN 3-5 FT
THROUGH TUESDAY. MID TO LATE WEEK...A WEAKENING ONSHORE PRESSURE
GRADIENT WILL TRANSLATE TO LIGHTER WINDS...FREQUENTLY 10 KT OR
LESS...AND SEAS SHOULD SUBSIDE TO 1-3 FT...HIGHEST BEYOND 20 NM.
MEANWHILE...SHOWERS/THUNDERSTORMS WILL REMAIN COMMON OVER COASTAL
WATERS THROUGH THIS WEEK. STRONGER THUNDERSTORMS COULD PRODUCE GUSTY
WINDS...FREQUENT LIGHTNING AND POOR VISIBILITY IN VERY HEAVY
RAINFALL. MARINERS SHOULD REMAIN ALERT FOR SPECIAL MARINE WARNINGS
AND MARINE WEATHER STATEMENTS.
MARINERS ARE ADVISED THAT SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL OCCUR EACH OF THE NEXT SEVERAL DAYS AND NIGHTS.
SOME OF THESE STORMS WILL PRODUCE FREQUENT LIGHTNING...HEAVY RAINS
REDUCING VISIBILITIES TO NEAR ZERO AT TIMES AND WIND GUSTS UP TO
AT LEAST 30 KT WITH BRIEFLY HIGHER SEAS. REMEMBER TO MONITOR OUR
FORECASTS AND YOUR NOAA WEATHER RADIO.
CONDITIONS WON/T BE MUCH DIFFERENT SUNDAY WITH ONSHORE
WINDS...SMALL SWELLS AND ASTRONOMICAL INFLUENCES FROM THE PERIGEE
AND FULL MOON. THIS WILL RESULT IN AT LEAST A MODERATE RISK OF RIP
CURRENTS AT AREA BEACHES.
WHILE WE START TO LOSE THE ASTRONOMICAL INFLUENCES AS WE GO THROUGH
THE WEEK...THERE IS STILL AN ONSHORE WIND COMPONENT AND POSSIBLE
SMALL SWELLS TO GENERATE A POSSIBLE ELEVATED RISK DURING AT LEAST THE
EARLY PART OF THE WEEK.
RIP CURRENTS...A MODERATE RISK OF RIP CURRENTS MAY BE UPGRADED TO
HIGH RISK AT TYBEE ISLAND LATER THIS MORNING...OTHERWISE AN
ELEVATED RISK FOR RIP CURRENTS COULD PERSIST INTO EARLY THIS WEEK.
&&
.TIDES/COASTAL FLOODING...
THROUGH TONIGHT...ASTRONOMICAL INFLUENCES DUE TO THE PERIGEAN
SPRING TIDE PLUS ONSHORE WINDS WILL MAINTAIN ELEVATED HIGH TIDE
LEVELS ALONG THE COAST. WHILE WE WILL BE CLOSE TO POSSIBLE
SHALLOW COASTAL FLOODING IN CHARLESTON HARBOR WITH THE MORNING
HIGH TIDE TODAY...A BETTER CHANCE FOR SHALLOW SALT WATER FLOODING
EXISTS WITH THE EVENING HIGH TIDE. COASTAL FLOOD ADVISORIES WILL
LIKELY BE REQUIRED FOR AT LEAST PARTS OF THE SC COAST...AND WE/LL
BE CLOSE TO THE ADVISORY CRITERIA FURTHER SOUTH...INCLUDING THE
SAVANNAH AREA. ALSO OF NOTE...PERIODS OF SHOWERS/THUNDERSTORMS
WITH HEAVY RAIN ARE EXPECTED. IF HEAVY RAIN FALLS IN COASTAL
COMMUNITIES...INCLUDING DOWNTOWN CHARLESTON AND/OR DOWNTOWN
SAVANNAH AROUND THE TIMES OF HIGH TIDE...MORE SIGNIFICANT FLOODING
IS POSSIBLE.
MONDAY AND TUESDAY...LINGERING ASTRONOMICAL INFLUENCES AND
PERSISTENT ONSHORE FLOW COULD PRODUCE A COUPLE OF ADDITIONAL CYCLES
OF SHALLOW SALT WATER FLOODING WITH THE NIGHTTIME HIGH
TIDE...ESPECIALLY ALONG THE SOUTH CAROLINA COAST. ALSO OF CONCERN...
PERIODS OF HEAVY RAIN ARE POSSIBLE ALONG THE COAST EARLY THIS
WEEK...AND LOCALIZED FLOODING IS POSSIBLE ESPECIALLY IF HEAVY RAIN
FALLS AROUND THE TIMES OF HIGH TIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...SPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
110 AM EDT SUN AUG 30 2015
.PREV DISCUSSION... /ISSUED 901 PM EDT SAT AUG 29 2015/
UPDATE...
UPDATED FORECAST IN GOOD SHAPE. SHRA STILL ACTIVE IN NW
CORNER...MIDDLE GA EAST OF KCSG AND FAR SE. LITTLE IF ANY
CONVECTION SEEN THIS AFTERNOON AND NONE EXPECTED OVERNIGHT.
ANOTHER ROUND OF SHRA LIKELY EARLY SUN MORNING BASED ON HRRR AND
SOME HIRES MODELS. NOT A SLAM DUNK BUT ENOUGH TO KEEP POPS FAIRLY
HIGH FOR THAT TIME OF NIGHT.
SNELSON
PREV DISCUSSION... /ISSUED 333 PM EDT SAT AUG 29 2015/
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
THE SHORT TERM MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD
KEEPING A MOIST AIRMASS IN PLACE. THE UPPER LEVEL LOW OVER THE
NORTHERN GULF WILL CONTINUE TO LIFT ACROSS SOUTH ALABAMA INTO
NORTHWEST GA BY SUNDAY EVENING AND NORTH OF THE FORECAST AREA
SUNDAY NIGHT. WEAK IMPULSES WILL CONTINUE TO LIFT ACROSS THE
FORECAST AREA AHEAD OF THE LOW. HIGH PRESSURE OVER THE CAROLINAS
WILL KEEP EASTERLY FLOW AT THE SURFACE. THIS WILL REINFORCE SOME
LOWER CLOUDS BY MORNING ACROSS THE AREA WITH MID LEVEL CEILINGS
EXPECTED ACROSS THE REGION. ALTHOUGH INSTABILITY WILL BE
MINIMAL...ISOLATED THUNDER WILL BE POSSIBLE AS THE IMPULSES LIFT
NORTH THROUGH TOMORROW. THE AREAS OF SHOWERS WILL CONTINUE
OVERNIGHT...WITH BEST CHANCES OVER WEST GA...BUT DO EXPECT SOME
LULLS. GUIDANCE TEMPERATURES ARE IN LINE AND HAVE TAKEN A BLEND OF
MAV/MET.
ATWELL
LONG TERM /MONDAY THROUGH SATURDAY/...
NO MAJOR CHANGES TO THE ONGOING LONG TERM FORECAST.
THE REMNANTS OF ERIKA STILL EXPECTED TO IMPACT THE CWFA NEXT WEEK.
FOR NOW...THE SYSTEM WILL REMAIN A LOW PRESSURE TROUGH AS IT COMES
ONSHORE ACROSS THE FLORIDA PANHANDLE EARLY NEXT WEEK.
THE PERSISTENT SOUTHERLY FLOW ALOFT WILL BRING ABUNDANT MOISTURE
NORTHWARD FROM THE GULF OF MEXICO FOR MUCH OF NEXT WEEK...SO CHANCE
POPS STILL NEEDED EVERY DAY. IN ADDITION...AN UPPER TROUGH ACROSS
THE EASTERN HALF OF THE COUNTRY WILL HELP KEEP TEMPERATURES MOSTLY
IN THE 80S THROUGH THE PERIOD.
WIND SHEAR IN THE GULF IS A LITTLE WEAKER...SO SOME REGENERATION OF
ERIKA IS POSSIBLE.
NLISTEMAA
&&
.AVIATION...
06Z UPDATE...
MAIN CONCERN IS POTENTIAL FOR ANY IFR/MVFR CEILINGS...PRECIP
TIMING...AND CHANCES FOR AFTERNOON THUNDERSTORMS. LOW CONFIDENCE
FORECAST FOR MOST ELEMENTS AND CONDITIONS WILL JUST HAVE TO BE
CLOSELY MONITORED FOR TRENDS. SURFACE WINDS ESE 10 KTS OR LESS.
//ATL CONFIDENCE...06Z UPDATE...
LOW CONFIDENCE ON PRECIP TIMING...CEILINGS...VSBYS...IMPACTS FROM
ANY AFTERNOON THUNDERSTORMS.
HIGH CONFIDENCE ON WINDS.
BDL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 81 67 85 69 / 50 20 30 20
ATLANTA 82 69 85 70 / 50 20 20 10
BLAIRSVILLE 76 62 82 63 / 40 20 30 20
CARTERSVILLE 81 66 87 68 / 40 20 20 10
COLUMBUS 87 69 89 72 / 50 20 20 10
GAINESVILLE 78 67 83 69 / 50 20 30 20
MACON 84 69 87 70 / 50 30 30 20
ROME 82 66 87 68 / 40 20 20 10
PEACHTREE CITY 83 68 86 69 / 50 20 20 10
VIDALIA 86 70 85 72 / 50 40 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BDL
LONG TERM....DEESE
AVIATION...BDL
AREA FORECAST DISCUSSION
NWS LINCOLN IL
324 AM CDT SUN AUG 30 2015
.SHORT TERM...(TODAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
08Z/3AM SURFACE ANALYSIS SHOWS A STATIONARY FRONTAL BOUNDARY
EXTENDING FROM JUST SOUTH OF CHICAGO TO NEAR KIRKSVILLE, MISSOURI.
WHILE CURRENT KILX RADAR IMAGERY INDICATES DRY CONDITIONS ACROSS THE
BOARD...A FEW SHOWERS ARE NOTED FURTHER SOUTHWEST FROM THE OZARKS
INTO THE OHIO RIVER VALLEY. MEANWHILE...LIGHT/VARIABLE WINDS AND
INCREASED LOW-LEVEL MOISTURE NEAR THE BOUNDARY HAVE LED TO THE
DEVELOPMENT OF FOG MAINLY ALONG/NORTHWEST OF A PITTSFIELD TO
BLOOMINGTON-NORMAL LINE. HRRR CONTINUES TO FOCUS MUCH OF THE
WIDESPREAD FOG ACROSS THIS AREA THROUGH MID-MORNING...SO WILL NEED
TO MONITOR VISBY TRENDS FOR A POSSIBLE DENSE FOG ADVISORY. FURTHER
EAST AND SOUTH ACROSS THE REMAINDER OF THE CWA...WILL ONLY MENTION
PATCHY FOG EARLY THIS MORNING. AFTER THE MORNING FOG
DISSIPATES...WIDELY SCATTERED SHOWERS/THUNDER WILL DEVELOP AHEAD OF
THE DECAYING FRONTAL BOUNDARY...PRIMARILY EAST OF THE ILLINOIS
RIVER. AFTERNOON HIGH TEMPERATURES WILL BE SIMILAR TO
YESTERDAY...PERHAPS A DEGREE OR TWO WARMER IN THE MIDDLE 80S.
&&
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
THE EXTENDED LOOKS WARM AND DRY AS UPPER-LEVEL RIDGING DOMINATES THE
EASTERN CONUS THROUGH THE END OF THE WEEK. A SLIGHT WEAKNESS IN THE
RIDGE APPEARS TO DEVELOP ACROSS ILLINOIS INTO THE OHIO RIVER
VALLEY...POTENTIALLY TRIGGERING ISOLATED AFTERNOON/EVENING
CONVECTION TUESDAY THROUGH FRIDAY. HOWEVER...MID-LEVEL WARMING
BENEATH THE RIDGE WILL LIKELY LEAD TO CAPPING AND AN OVERALL
SUPPRESSION OF CONVECTION. AS A RESULT...WILL MAINTAIN A DRY
FORECAST WITH HIGH TEMPERATURES CLIMBING INTO THE UPPER 80S AND
LOWER 90S EACH DAY. THE NEXT SIGNIFICANT CHANCE FOR PRECIPITATION
WILL LIKELY HOLD OFF UNTIL EARLY NEXT WEEK WHEN A SHORT-WAVE TROUGH
GRADUALLY FLATTENS THE PREVAILING RIDGE AND PUSHES A COLD FRONT INTO
THE REGION. MODELS ARE NOT IN AGREEMENT CONCERNING TIMING THIS FAR
OUT...BUT TYPICAL TREND IN THIS TYPE OF SCENARIO IS USUALLY SLOWER.
AS A RESULT...WILL MAINTAIN DRY WEATHER THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1154 PM CDT SAT AUG 29 2015
FOG FORMATION AND LOW CLOUDS ARE THE PRIMARY CONCERNS OVER THE
FIRST 6-9 HOURS OF THE TAF PERIOD. THE WEAKENING COLD FRONT HAS
BASICALLY STALLED OUT FROM NE TO SW ROUGHLY ALONG I-55 AS A
STATIONARY FRONT. AS A RESULT OF THE WEAK PRESSURE GRADIENT IN THE
VICINITY OF THE FRONT, THE WINDS WILL REMAIN LIGHT AND VARIABLE
OVERNIGHT. THAT WILL LEAD TO THE POTENTIAL FOR AREAS OF DENSE FOG
TO FORM, ESPECIALLY N-NW OF THE FRONT AROUND PIA AND BMI. FOG FOR
THE OTHER TERMINAL SITES COULD REMAIN MVFR, BUT HRRR AND RAP
OUTPUT CONTINUE TO SHOW AREAS OF DENSE FOG FARTHER SOUTH FROM SPI
TO CMI, SO WILL MONITOR DENSE FOG CLOSELY FOR POSSIBLE SIGNIFICANT
VIS REDUCTION FOR THE OTHER TERMINALS.
TOMORROW MORNING WINDS ARE FORECAST TO RETURN TO THE SOUTH-
SOUTHWEST AND REMAINING LESS THAN 10 KT THROUGH THE DAY.
CLOUDS WILL POSSIBLE DIP TO LIFR AT PIA AND BMI (OR ANY SITE THAT
EXPERIENCES DENSE FOG), WITH MVFR CLOUDS AT THE OTHER TAF SITES
FOR A FEW HOURS AFTER SUNRISE. BY MID MORNING, LOW CLOUDS SHOULD
LIFT TO VFR LEVELS AS DIURNAL MIXING INCREASES AND RAISES THE LCL.
CLOUDS ARE FORECAST TO PERSIST UNTIL LATER AFTERNOON, AS A LOBE OF
THE UPPER TROUGH RETROGRADES INTO IL FROM THE E-SE. SHOWER CHANCES
WILL INCREASE EAST OF CMI AND DEC, BUT WE KEPT THE TAF DRY FOR
NOW.
SKIES SHOULD BEGIN TO CLEAR OUT BY SUNDAY EVENING, WITH LIGHT
SOUTH WINDS THROUGH 31/06Z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1154 PM CDT SAT AUG 29 2015
.UPDATE...
ISSUED AT 900 PM CDT SAT AUG 29 2015
A LINGERING BAND OF SHOWERS WILL CONTINUE ACROSS CENTRAL AND
EASTERN ILLINOIS THIS EVENING, THEN BEGIN TO PROGRESS EAST AFTER
MIDNIGHT. THE UPPER LEVEL TROUGH AXIS EXTENDS ACROSS IL FROM NE TO
SW, AND WILL BE THE FOCUS FOR THE CONTINUED CHANCES OF PRECIP
OVERNIGHT. CLOUDS WILL PRIMARILY DOMINATE THE SKIES OVERNIGHT, BUT
PATCHES OF CLEARING ARE SHOWING UP IN EASTERN IOWA AND FAR WESTERN
IL ON THE LATEST SATELLITE IMAGES. ANY CLEARING NW OF THE IL RIVER
WILL LIKELY RESULT IN FOG FORMATION, WITH SOME AREAS SEEING DENSE
FOG. HAVE LEFT A MENTION OF FOG FOR NW OF THE IL RIVER, BUT THERE
IS SOME INDICATIONS IN THE HRRR AND RAP THAT THE FOG COULD AFFECT
SPOTTY AREAS IN THE REMAINDER OF OUR FORECAST AREA. FOR NOW, WILL
NOT INCLUDE FOG EVERYWHERE, BUT WILL WATCH CLOSELY FOR ANY
CLEARING IN THE CLOUDS EAST OF THE IL RIVER, WHICH WOULD INCREASE
FOG POTENTIAL THERE.
LOW TEMPS WILL BE MAINLY HELD IN THE MID 60S DUE TO CLOUD COVER
AND MINIMAL AIRMASS CHANGE OVERNIGHT UNDER LIGHT AND VARIABLE
WINDS. UPDATED THE WEATHER/POP/SKY GRIDS TO MATCH EXPECTED TRENDS.
THE REMAINDER OF THE FORECAST INFO APPEARS ON TRACK.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 228 PM CDT SAT AUG 29 2015
LATEST SURFACE MAP SHOWING FRONTAL BOUNDARY ARCING FROM THE
NORTHEAST TIP OF ILLINOIS TO EAST CENTRAL IOWA...BEFORE EXTENDING
SOUTHWEST INTO SOUTHEAST KANSAS. PRECIPITATION HAS LARGELY REMAINED
LIGHT AND SCATTERED...AND HAS BEEN MOSTLY EAST OF I-55 THE LAST
SEVERAL HOURS. DECENT SLUG OF DRY AIR ALOFT SEEN ON WATER VAPOR
IMAGERY SOUTH OF A SHORTWAVE...WHICH IS CURRENTLY DROPPING INTO
SOUTHERN IOWA. SHORT-RANGE MODEL GUIDANCE IS HAVING A BIT OF
DIFFICULTY AS TO THE AMOUNT OF REDEVELOPMENT...BUT THE HRRR IS
PERFORMING HALFWAY DECENTLY AND CONTINUES TO SUGGEST MAINLY SCATTERED
SHOWERS. THUNDER HAS BEEN STAYING AWAY FROM OUR AREA SO FAR...AND
WHILE MESOANALYSIS SHOWS RESPECTABLE CAPE VALUES OF 1000-1500 J/KG
THIS AFTERNOON...MID LEVEL LAPSE RATES ARE FAIRLY MODEST. THEREFORE
WILL CONTINUE MENTION WITH ONLY ISOLATED THUNDERSTORMS THROUGH
TONIGHT...WITH THE THREAT DIMINISHING FROM NORTHWEST TO SOUTHEAST.
SOME CONCERNS LATER IN THE NIGHT WITH POTENTIAL FOR SOME FOG...
MAINLY ACROSS THE NORTHWEST CWA. STILL QUITE A BIT OF LOWER
STRATOCUMULUS ACROSS MOST OF IOWA AND WISCONSIN. LATEST RAP MODEL
GUIDANCE SUGGESTS THIS CONTRACTING SOME MORE OVER THE NEXT SEVERAL
HOURS...BEFORE SIGNIFICANTLY EXPANDING AGAIN THIS EVENING WITH HIGH
PRESSURE EXPANDING OVER THE MIDWEST. MUCH OF THE AREA UNDERNEATH
THIS HIGH SAW FROM 1 TO SEVERAL INCHES OF RAIN IN THE LAST COUPLE
DAYS...AND IS MOST FAVORED FOR DENSE FOG POTENTIAL. HOWEVER...THE
RAP SHOWS THE FOG FIELD OOZING SOUTHWARD AFTER MIDNIGHT...PERHAPS AS
FAR AS PEORIA. THAT AREA ALREADY HAD PATCHY FOG IN THE GRIDS...BUT
AM THINKING IT WILL BE A BIT MORE WIDESPREAD AND WILL GO WITH AREAS
OF FOG INSTEAD.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 228 PM CDT SAT AUG 29 2015
SHOWERS AND ISOLATED THUNDERSTORMS COULD LINGER IN THE SOUTHEASTERN
PART OF THE CWA SUNDAY MORNING BUT THEN SPREAD BACK WEST
SOME...COVERING THE EASTERN HALF OF THE CWA...MAINLY EAST OF I-55.
THIS SHOULD BE THE END OF THE PCPN AS THE FRONTAL SYSTEM DIMINISHES
OVER THE AREA REMAINDER OF THE WEEKEND. FOG AND LOWER CLOUDS WILL
SEEN THIS MORNING ALONG AND BEHIND THE FRONT...SO THINKING IS THAT
THE FOG WILL CONTINUE INTO THE FIRST FEW HOURS OF SUNDAY MORNING.
HAVE INCLUDED A SLIGHT CHANCE OF SHOWERS FOR SUNDAY NIGHT...AGAIN
MAINLY EAST OF I-55 TIL MIDNIGHT...AND THEN IN THE EXTREME SOUTHEAST
AFTER MIDNIGHT.
BEYOND THIS UPPER LEVEL RIDGING WILL BUILD INTO THE NORTHERN PLAINS
AND NORTHERN MISS VALLEY. ON THE SFC...HIGH PRESSURE RIDGING WILL
BUILD BACK TOWARD THE AREA FROM THE SOUTHEAST. THE COMBINATION OF
THE TWO SHOULD HELP TO KEEP THE AREA DRY THROUGH THE BEGINNING OF
THE WEEK. TEMPS WILL BE IN THE LOWER TO MIDDLE 80S TOMORROW...BUT
THEN WARM INTO THE MIDDLE TO UPPER 80S FOR MONDAY INTO TUESDAY.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY...THOUGH SOME OF THE
MODELS CONTINUE TO BRING SOME SPOTTY POPS IN THE AREA DUE TO
SOUTHERLY FLOW ON THE SFC. FOR NOW...WILL ONLY HAVE SLIGHT CHC POPS
FOR WED ACROSS AREAS ALONG AND NORTH OF I-74 AND EAST OF I-57.
REMAINDER OF THE WEEK WITH BE DRY...EVEN INTO THE BEGINNING OF THE
LABOR DAY WEEKEND. TEMPS WILL REMAIN WELL ABOVE NORMAL IN THE
EXTENDED PERIOD SO HEAT COULD BE AN ISSUE LATER...BUT DEWPOINTS WILL
REMAIN LOW SO HEAT INDEX VALUES ARE NOT EXPECTED TO GET OVER 100
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1154 PM CDT SAT AUG 29 2015
FOG FORMATION AND LOW CLOUDS ARE THE PRIMARY CONCERNS OVER THE
FIRST 6-9 HOURS OF THE TAF PERIOD. THE WEAKENING COLD FRONT HAS
BASICALLY STALLED OUT FROM NE TO SW ROUGHLY ALONG I-55 AS A
STATIONARY FRONT. AS A RESULT OF THE WEAK PRESSURE GRADIENT IN THE
VICINITY OF THE FRONT, THE WINDS WILL REMAIN LIGHT AND VARIABLE
OVERNIGHT. THAT WILL LEAD TO THE POTENTIAL FOR AREAS OF DENSE FOG
TO FORM, ESPECIALLY N-NW OF THE FRONT AROUND PIA AND BMI. FOG FOR
THE OTHER TERMINAL SITES COULD REMAIN MVFR, BUT HRRR AND RAP
OUTPUT CONTINUE TO SHOW AREAS OF DENSE FOG FARTHER SOUTH FROM SPI
TO CMI, SO WILL MONITOR DENSE FOG CLOSELY FOR POSSIBLE SIGNIFICANT
VIS REDUCTION FOR THE OTHER TERMINALS.
TOMORROW MORNING WINDS ARE FORECAST TO RETURN TO THE SOUTH-
SOUTHWEST AND REMAINING LESS THAN 10 KT THROUGH THE DAY.
CLOUDS WILL POSSIBLE DIP TO LIFR AT PIA AND BMI (OR ANY SITE THAT
EXPERIENCES DENSE FOG), WITH MVFR CLOUDS AT THE OTHER TAF SITES
FOR A FEW HOURS AFTER SUNRISE. BY MID MORNING, LOW CLOUDS SHOULD
LIFT TO VFR LEVELS AS DIURNAL MIXING INCREASES AND RAISES THE LCL.
CLOUDS ARE FORECAST TO PERSIST UNTIL LATER AFTERNOON, AS A LOBE OF
THE UPPER TROUGH RETROGRADES INTO IL FROM THE E-SE. SHOWER CHANCES
WILL INCREASE EAST OF CMI AND DEC, BUT WE KEPT THE TAF DRY FOR
NOW.
SKIES SHOULD BEGIN TO CLEAR OUT BY SUNDAY EVENING, WITH LIGHT
SOUTH WINDS THROUGH 31/06Z.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHIMON
SHORT TERM...GEELHART
LONG TERM...AUTEN
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS JACKSON KY
133 AM EDT SUN AUG 30 2015
.UPDATE...
ISSUED AT 133 AM EDT SUN AUG 30 2015
UPDATED THE FORECAST TO INPUT THE LATEST OBSERVATIONS INTO THE
GRIDS FOR TEMPERATURES...DEW POINTS...AND WINDS. OTHERWISE NOT TOO
MANY CONCERNS WITH THIS UPDATE. ALL SHOWERS HAVE ENDED EARLIER AND
HAVE LEFT FOG IN THE FORECAST THROUGH DAWN.
UPDATE ISSUED AT 1036 PM EDT SAT AUG 29 2015
THE FORECAST THROUGH 12Z TOMORROW HAS BEEN UPDATED. REGIONAL RADAR
IMAGERY HAS SHOWN THAT SHOWER AND STORM ACTIVITY ACROSS CENTRAL
AND EASTERN KENTUCKY HAS ENDED OVER THE PAST COUPLE OF HOURS.
RAIN SHOWERS ACROSS TENNESSEE ARE ALSO CONTINUING TO RAPIDLY
DISSIPATE. CONSIDERING THE SUN HAS LONG SINCE STOPPED ADDING
ENERGY TO THE ATMOSPHERE...AND WITH NO NEW ACTIVITY FORMING
ANYWHERE IN OR NEAR OUR AREA...AND WITH ADDED SUPPORT FROM THE
LATEST MODEL DATA OF DRY WEATHER OVERNIGHT...THE DECISION WAS MADE
TO REMOVE PRECIPITATION FROM THE FORECAST THROUGH 12Z SUNDAY.
ISOLATED SHOWERS AND STORMS SHOULD START TO FIRE AGAIN TOMORROW
MORNING ONCE THE SUN HAS BEEN UP FOR AWHILE AND THE ATMOSPHERE
BECOMES REENERGIZED. THE HAZARDOUS WEATHER OUTLOOK HAS ALSO BEEN
UPDATED TO REFLECT NO HAZARDOUS WEATHER ACROSS THE AREA TONIGHT.
SOME VALLEY IS STILL EXPECTED TO FORM...BUT SHOULD NOT CAUSE ANY
ISSUES. THE NEW FORECAST AND HWO HAVE BOTH ALREADY BEEN ISSUED.
UPDATE ISSUED AT 732 PM EDT SAT AUG 29 2015
THE FORECAST IS ON TRACK SO FAR THIS EVENING. A FEW STRAY RAIN
SHOWERS AREA AFFECTING AREAS ALONG AND NORTH OF I64 AND DOWN IN
WAYNE COUNTY. THIS MATCHES WELL WITH THE SLIGHT CHANCE POPS
CURRENTLY IN THE LATEST HOURLY FORECAST GRIDS FOR BOTH THOSE
AREAS. THESE SHOWERS WILL DIMINISH STEADILY THIS EVENING AS THE
SUN GOES DOWN. THE LATEST HOURLY OBS AND BLENDED MODEL DATA HAVE
BEEN INGESTED INTO THE GRIDS TO ESTABLISH NEW TRENDS. ASIDE FROM
THAT THE FORECAST WAS UNCHANGED. THEREFORE...NO UPDATE IS
PLANNED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 355 PM EDT SAT AUG 29 2015
19Z SFC ANALYSIS SHOWS HIGH PRESSURE EXITING TO THE EAST WHILE A
BROAD AREA OF LOW PRESSURE IS DRIFTING TOWARD THE STATE FROM THE
CENTRAL PLAINS. THE INCREASE IN MOISTURE AND LACK OF A CAP HAVE
ALLOWED A FEW CELLS TO DEVELOP THROUGH WESTERN AND NORTHERN PARTS
OF THE AREA THIS AFTERNOON. SO FAR...THE COVERAGE HAS BEEN FAIRLY
SPARSE AND THAT SHOULD BE THE CASE INTO THE EVENING AS THE
DIURNALLY DRIVEN INSTABILITY WANES. TEMPERATURES ARE IN THE MID
80S AT MOST PLACES WITH DEWPOINTS IN THE MID 60S. UNDER PARTLY
SUNNY SKIES WINDS ARE FROM THE SOUTH TO SOUTHWEST AT AROUND 10
KTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT A BROAD AND RATHER WEAK
TROUGH OVER THE OHIO AND TENNESSEE VALLEYS WITH SLOW MOVING
BATCHES OF ENERGY CAUGHT OVER THE REGION...STUCK BETWEEN
MARGINALLY HIGHER HEIGHTS TO THE WEST AND SOUTHEAST. GIVEN THE
BROAD AGREEMENT WITH THE MODELS HAVE FAVORED THE HIGHER RESOLUTION
GUIDANCE FROM THE HRRR AND NAM12 FOR WEATHER DETAILS.
SENSIBLE WEATHER WILL FEATURE THE ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS DIMINISHING TOWARD AND AFTER SUNSET WITH PARTLY
CLOUDY SKIES ANTICIPATED THROUGH THE NIGHT. PATCHY VALLEY FOG WILL
AGAIN FORM TOWARDS DAWN WITH A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT LIKELY SETTING UP. SUNDAY WILL SEE A BETTER CHANCE FOR
CONVECTION THROUGHOUT THE CWA WITH MORE CLOUDS HELPING TO KEEP
TEMPERATURES ABOUT A CATEGORY COOLER...BUT WITH CONDITIONS EQUAL
OR EVEN MORE HUMID THAN TODAY. AGAIN PATCHY FOG AND A MINOR RIDGE
TO VALLEY TEMP SPLIT CAN BE EXPECTED LATER SUNDAY NIGHT INTO
MONDAY MORNING.
STARTED WITH THE SHORTBLEND FOR TEMPERATURES...DEWPOINTS...AND
WINDS THROUGH THE EVENING BEFORE GOING WITH THE SUPERBLEND FOR
THE REST OF THE PERIOD. DID ADJUST THE MIN TEMPERATURES EACH NIGHT
FOR TERRAIN DIFFERENCES. AS FOR POPS...ENDED UP CLOSER TO THE
DRIER MAV NUMBERS THROUGHOUT THE SHORT TERM PERIOD.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 330 PM EDT SAT AUG 29 2015
UPPER LEVEL RIDGING WILL REMAIN IN PLACE ACROSS MUCH OF THE EASTERN
CONUS THROUGHOUT THE EXTENDED. MEANWHILE...BOTH THE REMNANTS OF TS
ERIKA AND A WEAK UPPER LEVEL LOW OVER THE MISSISSIPPI RIVER VALLEY
WILL BE THE FEATURES THAT WILL PREVENT US FROM HAVING A COMPLETELY
DRY AND CLEAR WEEK AHEAD. THE UPPER LEVEL RIDGE WILL BE THE MAIN
PLAYER...KEEPING STABLE AIR ACROSS THE REGION DURING THE OVERNIGHT
HOURS AS THE TEMPERATURES COOL. HOWEVER...DURING THE
DAY...INCREASING TEMPERATURES AND THE ABOVE MENTIONED UPPER LEVEL
TRIGGERS WILL RESULT IN SOME ISL TO SCT SHOWERS AND THUNDERSTORMS
ACROSS THE REGION. OUR BEST CHANCES FOR SEEING PRECIP WILL BE DURING
THE DAY MONDAY AS THE LOW THAT WAS TS ERIKA MOVES FAR ENOUGH WEST TO
IMPACT FAR SE KY. IT WILL QUICKLY TRANSITION TO THE NE
HOWEVER...WITH AN APPROACHING SHORTWAVE AND THE DIMINISHING UPPER
LEVEL LOW OVER THE MISSISSIPPI VALLEY SHIFTING EASTWARD ACROSS KY
BY MID WEEK.
MOST OF THE WINDS THROUGH THIS PERIOD WILL BE FROM THE EAST AT THE
SURFACE...AND FROM THE WSW IN THE MID AND UPPER LEVELS. IN OTHER
WORDS...IT IS NOT VERY FAVORABLE FOR SUSTAINABLE THUNDERSTORM
DEVELOPMENT. NOT GOING TO RULE OUT SOME RUMBLES OF THUNDER...SO DID
KEEP MENTION OF TSRA IN FORECAST...BUT DON/T EXPECT STORMS TO BECOME
VERY TALL OR BE FAST MOVERS. NOT TO MENTION LATEST GFS FORECAST
SOUNDINGS DON/T SHOW LI/S BELOW -5C AND CAPE ABOVE 1500 J/KG /WITH
THE EXCEPTION OF MONDAY/...SO NOTHING TOO CONCERNABLE EXPECTED
THROUGH THE WEEK AT THIS POINT.
THE OVERALL RIDGE PATTERN AND LACK OF WIDESPREAD CLOUD COVER WILL
ALLOW TEMPERATURES TO SLOWLY INCREASE EACH DAY THROUGHOUT THE WEEK.
WHILE HIGH TEMPERATURES ON MONDAY WILL STILL BE CONTAINED IN THE LOW
TO MID 80S...WE COULD SEE UPPER 80S BY TUESDAY...AND POSSIBLY EVEN A
90 DEGREE SPOT OR TWO TO ROUND OUT THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 133 AM EDT SUN AUG 30 2015
THE MAIN CONCERN AT THE TAF SITES THROUGH DAWN WILL BE THE
DEVELOPMENT OF FOG. THOUGH...WITH SOME CLOUD COVER LINGERING OVER
EAST KENTUCKY...FORECASTING THE ONSET WILL BE QUITE DIFFICULT.
HAVE USED A TEMPO GROUP AT EACH SITE BESIDES JKL AS FOG SHOULD
REMAIN IN THE VALLEYS. ALSO...DESPITE SOME SLIGHTLY HIGHER DEW
POINTS...FOG SHOULD BE MVFR TO IFR AT WORST. WITH GENERALLY LIGHT
WINDS INTO THE DAY WITH SOME INCREASE IN SOUTHWEST FLOW WILL BE
THE NORM. EXPECTING SHOWERS AND THUNDERSTORMS TO DEVELOP BY 18Z
AND PERSIST INTO THE EVENING. COVERAGE CONTINUES TO BE A BIT IN
QUESTION SO WILL GO WITH VCTS AT THE SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
355 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A WEAK COLD FRONTAL BOUNDARY FROM QUEBEC WILL CROSS THE REGION
TODAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION BY
MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER AIR WITH CANADIAN
HIGH PRESSURE MONDAY NIGHT AND TUESDAY. RETURN WEST... SOUTHWEST
WINDS ON WEDNESDAY AS THE HIGH MOVES EAST OF THE REGION WILL BRING
MUCH WARMER CONDITIONS ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER SHORTWAVE IS RAPIDLY SLIDING ACROSS SOUTHERN QUEBEC EARLY
THIS MORNING. ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH THIS
FEATURE ARE CURRENTLY PUSHING ACROSS NORTHERN AND CENTRAL PORTIONS
OF OUR FORECAST AREA. THIS PRECIPITATION IS ALSO MOVING FAIRLY
QUICKLY; THE BULK OF THE ACTIVITY IS SLATED TO MOVE INTO NEW
BRUNSWICK BY MID MORNING. THIS IS SUPPORTED BY THE LATEST HRRR
GUIDANCE, WHICH HAS ALL BUT ONE OR TWO SHOWERS EXITING OUR AREA
AROUND 14Z/10 AM. IT IS NOTED THAT THE HRRR ALSO TRIES TO PRODUCE
SOME POP-UP SHOWERS ACROSS THE NORTH THIS AFTERNOON, BUT WITH
DRIER AIR WORKING IN BEHIND THE UPPER WAVE, CURRENT THINKING IS
THAT ALL WE`LL SEE IS SOME CUMULUS CLOUDS WITH PERHAPS SOME VIRGA.
BRIEF RIDGING BUILDS IN FOR LATER THIS AFTERNOON INTO TONIGHT.
HOWEVER, ANOTHER STRONGER UPPER TROUGH AND SURFACE COLD FRONT WILL
APPROACH LATE TONIGHT, WITH SHOWERS MOVING INTO NORTHERN AREAS
AFTER MIDNIGHT. HIGHS TODAY WILL BE IN THE MID 70S TO AROUND 80
WHILE OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE L/WV PATTERN OVR NA INTO THE LATE WEEK WILL FEATURE A
BUILDING MDTLY HI AMPLITUDE RIDGE OVR THE ERN GREAT LKS AS AN
UPPER TROF BUILDS SWRD OVR THE W COAST. THIS PLACES NRN/ERN ME IN
THE NE QUADRANT OF THIS RIDGE... MEANING THAT ALTHOUGH TEMPS WILL
LIKELY AVG ABV NORMAL FOR THIS PD...THE REGION WILL BE SUBJECT TO
COLD FRONTAL PASSAGES AS S/WVS CRESTING THE RIDGE IN CNTRL CAN N
OF THE GREAT LKS DROP ESEWRD INTO CAN MARITIMES.
THE FIRST OF THESE S/WVS WILL BE CROSSING JUST N OF THE FA ON MON
BRINGING CLDNSS AND SHWRS TO MSLY NRN PTNS OF THE FA LATE MON MON
THRU MIDDAY AND PERHAPS INTO CNTRL PTNS OF THE FA ERLY TO MID
AFTN. ATTM...WARM MID LVL TEMPS WILL LIKELY KEEP SHWRS FROM
DEVELOPING INTO TSTMS OVR ME...BUT AN ISOLD TSTM CANNOT BE
COMPLETELY RULED OUT TUE AFTN ALG THE NE ME/NW NB BORDER BEFORE
THE S/WV MOVES E OF THE FA LATE MON AFTN. RNFL AMOUNTS ARE LIKELY
TO BE GREATEST IN THE ST JOHN VLY WHERE UP TO A TENTH OF AN INCH
IS POSSIBLE...WITH LESSER OR NO RN AS ONE TRAVERSES FURTHER S.
BEHIND THE FRONT...COOLER AND MUCH DRIER AIR FROM N CNTRL CAN WILL
ADVECT SWRD INTO THE FA MON NGT INTO TUE...WITH DWPTS DROPPING
INTO THE 40S ACROSS NRN AND CNTRL PTNS OF THE FA BY TUE MORN.
TEMPS WILL INITIALLY BE SLOW TO RISE MON MORN WITH MDT LLVL COLD
ADVCN...THEN MAKE MAKE A LITTLE FASTER RECOVERY TO NEAR SEASONAL
NORMS TUE AFTN AS THE LLVL TEMP ADVCN BECOMES MORE NEUTRAL ALL
UNDER SUNNY SKIES. A DRY WARM FRONT WILL CROSS THE REGION BY WED
MORN AS THE SFC HI MOVES S OF THE FA TUE NGT. WINDS...WHICH WILL
BEGIN NEAR CALM TUE EVE WILL SHIFT TO THE LGT SW LATE TUE NGT AS
SKIES BECOME PTLY CLDY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WITH THE UPPER RIDGE FLEXING SW TO NE OVR THE FA...TEMPS WILL
RAPIDLY RISE ON WED INTO THE 80S OVR THE REGION WITH A WSW WIND
AND PTLY TO MSLY SUNNY SKIES AS HUMIDITY RISES WITH INCREASING SFC
DWPTS REACHING BACK INTO THE LOWER TO MID 60S. A VERY WEAK S/WV
AND ASSOCIATED WEAK COLD FRONT COULD RESULT IN ISOLD TO SCT
MID/LATE AFTN AND ERLY EVE TSTMS...MSLY ACROSS THE N. WHATS LEFT
OF THIS BOUNDARY WILL LIKELY SLIDE S AND W OF THE FA BY
THU...PERHAPS BEING A FOCUS OF SCT AFTN SHWRS/TSTMS ALG THE SW
FLANK OF OUR FA ACROSS WRN AND CNTRL ME. HI TEMPS OVR E CNTRL AND
INTERIOR DOWNEAST AREAS WILL CONT VERY WARM SIMILAR TO WED...BUT
ACROSS THE N SHOULD BE A LITTLE COOLER (UPPER 70S TO LOWER 80S)
AND DRIER AS SFC DWPTS FALL BACK INTO THE 50S BEHIND THE WEAK
COLD FRONT.
AFTWRDS FOR FRI AND SAT...LONGER RANGE MODELS DISAGREE CONCERNING
WHETHER THE FA WILL BE IN SHALLOW COOLER AIR FROM NE CANADA OR
MUCH WARMER AND MORE HUMID AIR FROM THE UPPER MIDWEST. GIVEN
THAT EVEN MINOR DIFFERENCES IN TMG OF WEAK S/WVS WILL BE PIVOTAL
IN DETERMINING THE TMG OF FRONTS ACROSS THE FA...WE KEPT CLOSE TO
THE SUPERBLEND AVG OF LONGER RANGE MODELS FOR HI TEMPS ON FRI AND
SAT WHICH STILL GIVES THE REGION ABV NORMAL TEMPS...BUT WITH LOW
CERTAINTY ON EITHER DAY. FOR NOW...WE KEPT FCST RN POPS EACH DAY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MAINLY VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
ONLY EXCEPTION WILL BE BRIEF MVFR CEILINGS WILL BE POSSIBLE AT THE
NORTHERN TERMINALS EARLY THIS MORNING AS SHOWERS MOVE THROUGH.
SHORT TERM: MAINLY VFR...XCPT PERHAPS A BRIEF PD OR TWO OF MVFR
CLGS/VSBYS OVR NRN TAF SITES WITH HEAVIER SHWRS ON MON AND AGAIN
WED AFTN/ERLY EVE.
&&
.MARINE...
NEAR TERM: NO HEADLINES WILL BE NEEDED OVER THE WATERS TODAY OR
TONIGHT AS HIGH PRESSURE REMAINS POSITIONED ACROSS THE REGION.
SHORT TERM: NO HDLNS AND LGT SEAS XPCTD...REACHING 2 TO 3 FT OVR
OUR OUTER MZS AND 1 TO 2 FT ALG THE NEAR SHORE WATERS. ABOUT 90
AND 70 PERCENT RESPECTIVELY OF WW3 WV GUIDANCE WAS USED TO PRODUCE
FCST WV HTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
349 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A WEAK COLD FRONTAL BOUNDARY FROM QUEBEC WILL CROSS THE REGION
TODAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION
BY MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER AIR WITH
CANADIAN HIGH PRESSURE MONDAY NIGHT AND TUESDAY. RETURN WEST...
SOUTHWEST WINDS ON WEDNESDAY AS THE HIGH MOVES EAST OF THE REGION
WILL BRING MUCH WARMER CONDITIONS ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER SHORTWAVE IS RAPIDLY SLIDING ACROSS SOUTHERN QUEBEC EARLY
THIS MORNING. ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH THIS
FEATURE ARE CURRENTLY PUSHING ACROSS NORTHERN AND CENTRAL PORTIONS
OF OUR FORECAST AREA. THIS PRECIPITATION IS ALSO MOVING FAIRLY
QUICKLY; THE BULK OF THE ACTIVITY IS SLATED TO MOVE INTO NEW
BRUNSWICK BY MID MORNING. THIS IS SUPPORTED BY THE LATEST HRRR
GUIDANCE, WHICH HAS ALL BUT ONE OR TWO SHOWERS EXITING OUR AREA
AROUND 14Z/10 AM. IT IS NOTED THAT THE HRRR ALSO TRIES TO PRODUCE
SOME POP-UP SHOWERS ACROSS THE NORTH THIS AFTERNOON, BUT WITH
DRIER AIR WORKING IN BEHIND THE UPPER WAVE, CURRENT THINKING IS
THAT ALL WE`LL SEE IS SOME CUMULUS CLOUDS WITH PERHAPS SOME VIRGA.
BRIEF RIDGING BUILDS IN FOR LATER THIS AFTERNOON INTO TONIGHT.
HOWEVER, ANOTHER STRONGER UPPER TROUGH AND SURFACE COLD FRONT WILL
APPROACH LATE TONIGHT, WITH SHOWERS MOVING INTO NORTHERN AREAS
AFTER MIDNIGHT. HIGHS TODAY WILL BE IN THE MID 70S TO AROUND 80
WHILE OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE L/WV PATTERN OVR NA WILL FEATURE A BUILDING MDTLY HI AMPLITUDE
RIDGE OVR THE ERN GREAT LKS AS AN UPPER TROF BUILDS SWRD OVR THE W
COAST. THIS PLACES NRN/ERN ME IN THE NE QUADRANT OF THIS RIDGE...
MEANING THAT ALTHOUGH TEMPS WILL LIKELY AVG ABV NORMAL FOR THIS
PD...THE REGION WILL BE SUBJECT TO COLD FRONTAL PASSAGES AS S/WVS
CRESTING THE RIDGE IN CNTRL CAN N OF THE GREAT LKS DROP ESEWRD
INTO CAN MARITIMES.
THE FIRST OF THESE S/WVS WILL BE CROSSING JUST N OF THE FA ON MON
BRINGING CLDNSS AND SHWRS TO MSLY NRN PTNS OF THE FA LATE MON MON
THRU MIDDAY AND PERHAPS INTO CNTRL PTNS OF THE FA ERLY TO MID
AFTN. ATTM...WARM MID LVL TEMPS WILL LIKELY KEEP SHWRS FROM
DEVELOPING INTO TSTMS OVR ME...BUT AN ISOLD TSTM CANNOT BE
COMPLETELY RULED OUT TUE AFTN ALG THE NE ME/NW NB BORDER BEFORE
THE S/WV MOVES E OF THE FA LATE MON AFTN. RNFL AMOUNTS ARE LIKELY
TO BE GREATEST IN THE ST JOHN VLY WHERE UP TO A TENTH OF AN INCH
IS POSSIBLE...WITH LESSER OR NO RN AS ONE TRAVERSES FURTHER S.
BEHIND THE FRONT...COOLER AND MUCH DRIER AIR FROM N CNTRL CAN WILL
ADVECT SWRD INTO THE FA MON NGT INTO TUE...WITH DWPTS DROPPING
INTO THE 40S ACROSS NRN AND CNTRL PTNS OF THE FA BY TUE MORN.
TEMPS WILL INITIALLY BE SLOW TO RISE MON MORN WITH MDT LLVL COLD
ADVCN...THEN MAKE MAKE A LITTLE FASTER RECOVERY TO NEAR SEASONAL
NORMS TUE AFTN AS THE LLVL TEMP ADVCN BECOMES MORE NEUTRAL ALL
UNDER SUNNY SKIES. A DRY WARM FRONT WILL CROSS THE REGION BY WED
MORN AS THE SFC HI MOVES S OF THE FA TUE NGT. WINDS...WHICH WILL
BEGIN NEAR CALM TUE EVE WILL SHIFT TO THE LGT SW LATE TUE NGT AS
SKIES BECOME PTLY CLDY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WITH THE UPPER RIDGE FLEXING SW TO NE OVR THE FA...TEMPS WILL
RAPIDLY RISE ON WED INTO THE 80S OVR THE REGION WITH A WSW WIND
AND PTLY TO MSLY SUNNY SKIES AS HUMIDITY RISES WITH INCREASING SFC
DWPTS REACHING BACK INTO THE LOWER TO MID 60S. A VERY WEAK S/WV
AND ASSOCIATED WEAK COLD FRONT COULD RESULT IN ISOLD TO SCT
MID/LATE AFTN AND ERLY EVE TSTMS...MSLY ACROSS THE N. WHATS LEFT
OF THIS BOUNDARY WILL LIKELY SLIDE S AND W OF THE FA BY
THU...PERHAPS BEING A FOCUS OF SCT AFTN SHWRS/TSTMS ALG THE SW
FLANK OF OUR FA ACROSS WRN AND CNTRL ME. HI TEMPS OVR E CNTRL AND
INTERIOR DOWNEAST AREAS WILL CONT VERY WARM SIMILAR TO WED...BUT
ACROSS THE N SHOULD BE A LITTLE COOLER (UPPER 70S TO LOWER 80S)
AND DRIER AS SFC DWPTS FALL BACK INTO THE 50S BEHIND THE WEAK
COLD FRONT.
AFTWRDS FOR FRI AND SAT...LONGER RANGE MODELS DISAGREE CONCERNING
WHETHER THE FA WILL BE IN SHALLOW COOLER AIR FROM NE CANADA OR
MUCH WARMER AND MORE HUMID AIR FROM THE UPPER MIDWEST. GIVEN
THAT EVEN MINOR DIFFERENCES IN TMG OF WEAK S/WVS WILL BE PIVOTAL
IN DETERMINING THE TMG OF FRONTS ACROSS THE FA...WE KEPT CLOSE TO
THE SUPERBLEND AVG OF LONGER RANGE MODELS FOR HI TEMPS ON FRI AND
SAT WHICH STILL GIVES THE REGION ABV NORMAL TEMPS...BUT WITH LOW
CERTAINTY ON EITHER DAY. FOR NOW...WE KEPT FCST RN POPS EACH DAY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MAINLY VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
ONLY EXCEPTION WILL BE BRIEF MVFR CEILINGS WILL BE POSSIBLE AT THE
NORTHERN TERMINALS EARLY THIS MORNING AS SHOWERS MOVE THROUGH.
SHORT TERM: MAINLY VFR...XCPT PERHAPS A BRIEF PD OR TWO OF MVFR
CLGS/VSBYS OVR NRN TAF SITES WITH HEAVIER SHWRS ON MON AND AGAIN
WED AFTN/ERLY EVE.
&&
.MARINE...
NEAR TERM: NO HEADLINES WILL BE NEEDED OVER THE WATERS TODAY OR
TONIGHT AS HIGH PRESSURE REMAINS POSITIONED ACROSS THE REGION.
SHORT TERM: NO HDLNS AND LGT SEAS XPCTD...REACHING 2 TO 3 FT OVR
OUR OUTER MZS AND 1 TO 2 FT ALG THE NEAR SHORE WATERS. ABOUT 90
AND 70 PERCENT RESPECTIVELY OF WW3 WV GUIDANCE WAS USED TO PRODUCE
FCST WV HTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
348 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A WEAK COLD FRONTAL BOUNDARY FROM QUEBEC WILL CROSS THE REGION
TODAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION
BY MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER AIR WITH
CANADIAN HIGH PRESSURE MONDAY NIGHT AND TUESDAY. RETURN WEST...
SOUTHWEST WINDS ON WEDNESDAY AS THE HIGH MOVES EAST OF THE REGION
WILL BRING MUCH WARMER CONDITIONS ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPPER SHORTWAVE IS RAPIDLY SLIDING ACROSS SOUTHERN QUEBEC EARLY
THIS MORNING. ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH THIS
FEATURE ARE CURRENTLY PUSHING ACROSS NORTHERN AND CENTRAL PORTIONS
OF OUR FORECAST AREA. THIS PRECIPITATION IS ALSO MOVING FAIRLY
QUICKLY; THE BULK OF THE ACTIVITY IS SLATED TO MOVE INTO NEW
BRUNSWICK BY MID MORNING. THIS IS SUPPORTED BY THE LATEST HRRR
GUIDANCE, WHICH HAS ALL BUT ONE OR TWO SHOWERS EXITING OUR AREA
AROUND 14Z/10 AM. IT IS NOTED THAT THE HRRR ALSO TRIES TO PRODUCE
SOME POP-UP SHOWERS ACROSS THE NORTH THIS AFTERNOON, BUT WITH
DRIER AIR WORKING IN BEHIND THE UPPER WAVE, CURRENT THINKING IS
THAT ALL WE`LL SEE IS SOME CUMULUS CLOUDS WITH PERHAPS SOME VIRGA.
BRIEF RIDGING BUILDS IN FOR LATER THIS AFTERNOON INTO TONIGHT.
HOWEVER, ANOTHER STRONGER UPPER TROUGH AND SURFACE COLD FRONT WILL
APPROACH LATE TONIGHT, WITH SHOWERS MOVING INTO NORTHERN AREAS
AFTER MIDNIGHT. HIGHS TODAY WILL BE IN THE MID 70S TO AROUND 80
WHILE OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO LOWER 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THE L/WV PATTERN OVR NA WILL FEATURE A BUILDING MDTLY HI AMPLITUDE
RIDGE OVR THE ERN GREAT LKS AS AN UPPER TROF BUILDS SWRD OVR THE W
COAST. THIS PLACES NRN/ERN ME IN THE NE QUADRANT OF THIS RIDGE...
MEANING THAT ALTHOUGH TEMPS WILL LIKELY AVG ABV NORMAL FOR THIS
PD...THE REGION WILL BE SUBJECT TO COLD FRONTAL PASSAGES AS S/WVS
CRESTING THE RIDGE IN CNTRL CAN N OF THE GREAT LKS DROP ESEWRD
INTO CAN MARITIMES.
THE FIRST OF THESE S/WVS WILL BE CROSSING JUST N OF THE FA ON MON
BRINGING CLDNSS AND SHWRS TO MSLY NRN PTNS OF THE FA LATE MON MON
THRU MIDDAY AND PERHAPS INTO CNTRL PTNS OF THE FA ERLY TO MID
AFTN. ATTM...WARM MID LVL TEMPS WILL LIKELY KEEP SHWRS FROM
DEVELOPING INTO TSTMS OVR ME...BUT AN ISOLD TSTM CANNOT BE
COMPLETELY RULED OUT TUE AFTN ALG THE NE ME/NW NB BORDER BEFORE
THE S/WV MOVES E OF THE FA LATE MON AFTN. RNFL AMOUNTS ARE LIKELY
TO BE GREATEST IN THE ST JOHN VLY WHERE UP TO A TENTH OF AN INCH
IS POSSIBLE...WITH LESSER OR NO RN AS ONE TRAVERSES FURTHER S.
BEHIND THE FRONT...COOLER AND MUCH DRIER AIR FROM N CNTRL CAN WILL
ADVECT SWRD INTO THE FA MON NGT INTO TUE...WITH DWPTS DROPPING
INTO THE 40S ACROSS NRN AND CNTRL PTNS OF THE FA BY TUE MORN.
TEMPS WILL INITIALLY BE SLOW TO RISE MON MORN WITH MDT LLVL COLD
ADVCN...THEN MAKE MAKE A LITTLE FASTER RECOVERY TO NEAR SEASONAL
NORMS TUE AFTN AS THE LLVL TEMP ADVCN BECOMES MORE NEUTRAL ALL
UNDER SUNNY SKIES. A WARM DRY FRONT WILL CROSS THE REGION BY WED
MORN AS THE SFC HI MOVES S OF THE FA TUE NGT. WINDS...WHICH WILL
BEGIN NEAR CALM TUE EVE WILL SHIFT TO THE LGT SW LATE TUE NGT AS
SKIES BECOME PTLY CLDY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WITH THE UPPER RIDGE FLEXING SW TO NE OVR THE FA...TEMPS WILL
RAPIDLY RISE ON WED INTO THE 80S OVR THE REGION WITH A WSW WIND
AND PTLY TO MSLY SUNNY SKIES AS HUMIDITY RISES WITH INCREASING SFC
DWPTS REACHING BACK INTO THE LOWER TO MID 60S. A VERY WEAK S/WV
AND ASSOCIATED WEAK COLD FRONT COULD RESULT IN ISOLD TO SCT
MID/LATE AFTN AND ERLY EVE TSTMS...MSLY ACROSS THE N. WHATS LEFT
OF THIS BOUNDARY WILL LIKELY SLIDE S AND W OF THE FA BY
THU...PERHAPS BEING A FOCUS OF SCT AFTN SHWRS/TSTMS ALG THE SW
FLANK OF OUR FA ACROSS WRN AND CNTRL ME. HI TEMPS OVR E CNTRL AND
INTERIOR DOWNEAST AREAS WILL CONT VERY WARM SIMILAR TO WED...BUT
ACROSS THE N SHOULD BE A LITTLE COOLER (UPPER 70S TO LOWER 80S)
AND DRIER AS SFC DWPTS FALL BACK INTO THE 50S BEHIND THE WEAK
COLD FRONT.
AFTWRDS FOR FRI AND SAT...LONGER RANGE MODELS DISAGREE CONCERNING
WHETHER THE FA WILL BE IN SHALLOW COOLER AIR FROM NE CANADA OR
MUCH WARMER AND MORE HUMID AIR FROM THE UPPER MIDWEST. GIVEN
THAT EVEN MINOR DIFFERENCES IN TMG OF WEAK S/WVS WILL BE PIVOTAL
IN DETERMINING THE TMG OF FRONTS ACROSS THE FA...WE KEPT CLOSE TO
THE SUPERBLEND AVG OF LONGER RANGE MODELS FOR HI TEMPS ON FRI AND
SAT WHICH STILL GIVES THE REGION ABV NORMAL TEMPS...BUT WITH LOW
CERTAINTY ON EITHER DAY. FOR NOW...WE KEPT FCST RN POPS EACH DAY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MAINLY VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
ONLY EXCEPTION WILL BE BRIEF MVFR CEILINGS WILL BE POSSIBLE AT THE
NORTHERN TERMINALS EARLY THIS MORNING AS SHOWERS MOVE THROUGH.
SHORT TERM: MAINLY VFR...XCPT PERHAPS A BRIEF PD OR TWO OF MVFR
CLGS/VSBYS OVR NRN TAF SITES WITH HEAVIER SHWRS ON MON AND AGAIN
WED AFTN/ERLY EVE.
&&
.MARINE...
NEAR TERM: NO HEADLINES WILL BE NEEDED OVER THE WATERS TODAY OR
TONIGHT AS HIGH PRESSURE REMAINS POSITIONED ACROSS THE REGION.
SHORT TERM: NO HDLNS AND LGT SEAS XPCTD...REACHING 2 TO 3 FT OVR
OUR OUTER MZS AND 1 TO 2 FT ALG THE NEAR SHORE WATERS. ABOUT 90
AND 70 PERCENT RESPECTIVELY OF WW3 WV GUIDANCE WAS USED TO PRODUCE
FCST WV HTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1244 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A WEAK COLD FRONT FROM QUEBEC WILL CROSS THE REGION SUNDAY
AFTERNOON. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE STATE
LATER MONDAY AFTERNOON AND MONDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
1240 AM UPDATE...ONLY REAL CHANGE WAS TO ADJUST POPS ACCORDING TO
CURRENT RADAR AND HI-RES MODEL TRENDS. BOTH THE HRRR AND THE RAP
BRING PRECIP THROUGH FASTER THAN PREVIOUSLY FORECASTED, AND THE
LATEST RADAR SUPPORTS THIS IDEA. ALSO BROUGHT ISOLATED POPS A BIT
FURTHER SOUTH INTO PORTION OF THE CENTRAL HIGHLANDS THROUGH
DAYBREAK AS THERE ARE SOME DECENT RADAR RETURNS APPROACHING
SOUTHERN PISCATAQUIS COUNTY AT THIS HOUR. MUCH OF THIS IS LIKELY
NOT HITTING THE GROUND, BUT CAN`T RULE OUT A BRIEF SHOWER.
OTHERWISE THE FORECAST IS IN GOOD SHAPE AND NO OTHER CHANGES WERE
NEEDED.
PREVIOUS DISCUSSION...A FEW SHOWERS ARE EXPECTED ACROSS THE
NORTHERN AND WESTERN AREAS LATER TONIGHT INTO EARLY SUNDAY.
CLOUDS WILL CONTINUE TO THICKEN TONIGHT IN ADVANCE OF A COLD FRONT
APCHG FROM QUEBEC. DEWPOINTS IN THE LOW 60S WERE SITTING BACK IN
QUEBEC AHEAD OF THE FRONT. THIS AIRMASS WILL MOVE INTO THE REGION
OVERNIGHT. SOUNDING DATA SHOWED PROFILE MOISTENING UP THROUGH
700MBS ACROSS NORTHERN AND WESTERN AREAS. PWATS CLIMB TO AROUND
1.40 INCHES. INSTABILITY LOOKS TO BE WEAK AND LIMITED TO THE
MAINE-QUEBEC BORDER. BEST CAPES APPEARS TO BE ELEVATED AND LESS
THAN 200 JOULES. THEREFORE, DID NOT INCLUDE ANY MENTION OF THUNDER
BASED ON THIS THINKING. STAYED W/30-40% POPS IN THE AFOREMENTIONED
AREAS THROUGH SUNDAY MORNING. FURTHER S INTO CENTRAL AND DOWNEAST
AREAS JUST SOME CLOUDS AND PERHAPS A SPRINKLE IN THE CENTRAL
HIGHLANDS. DECIDED TO LEAVE OUT ANY MENTION OF SHOWERS IN THESE
AREAS AS CLOUD BASE WILL BE 10K FT AND HIGHER. STAYED W/THE MIDNIGHT
CREW`S THINKING OF OVERNIGHT LOW IN THE MID/UPPER 50S FOR THE NORTH
AND WEST W/UPPER 50S AND LOWER 60S CENTRAL AND DOWNEAST.
USED A CONSENSUS BLEND OF THE NAM12 AND GFS FOR SUNDAY FOR SOME
SHOWERS IN THE MORNING ACROSS THE NORTHERN AREAS AS THE FRONT
SLIDES ACROSS THE REGION. SOUNDINGS DO SUPPORT SOME CAPE OF
300-500 JOULES BUT MOISTURE IS LIMITED BELOW 700MBS AND MID LEVEL
LAPSE RATES ARE MEAGER AT BEST(6.0C/KM). ATTM, DECISION WAS TO
LEAVE OUT THE MENTION OF TSTMS. NOT A WASHOUT BY ANY STRETCH AS
SUNSHINE WILL RETURN AND W/A WEST WIND, AFTERNOON TEMPS SHOULD
CLIMB INTO THE UPPER 70S TO LOWER 80S. QPF THROUGH SUNDAY
EXPECTED TO BE LESS THAN 0.10 INCHES. PARTIAL CLEARING SUNDAY
NIGHT W/THE POTENTIAL FOR FOG. ADDED PATCHY FOG ESPECIALLY
NORTHERN 1/2 OF THE CWA W/A SSW WIND.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. A SFC LOW
WITH A CO-LOCATED UPPER LOW PRESSURE TROUGH WILL BE MOVING TO THE
EAST OF THE AREA AT THE START OF THE PERIOD. HIGHER PRESSURE WILL
BUILD ACROSS THE REGION THROUGH THE DAY MON. THE HIGH WILL CREST
OVER THE AREA AT THE END OF THE PERIOD.
LOADED A BLEND OF THE NAM/GFS/GEM/ECMWF FOR T/DP/WND/POP. LOADED
HPC GUIDANCE FOR QPF FIRST 3 PERIOD...A BLEND OF GFS/ECMWF LAST 3
PERIOD. ADD 15 PERCENT TO WNDS FOR GUSTS OVER LAND 25 PERCENT OVER
THE COASTAL WATERS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE EXTENDED MODELS ARE IN GOOD AGREEMENT. A HIGH PRESSURE RIDGE
WILL BE CRESTED OVER THE AREA AT THE START OF THE PERIOD. A UPPER
LEVEL TROUGH WILL MOVE THROUGH THE AREA NORTH TO SOUTH THROUGH THE
DAY WEDNESDAY. BRINGING A CHANCE FOR A FEW SHOWER ACROSS THE
REGION. BY EARLY THURS MRNG THE TROUGH WILL BE OFF THE COAST.
HIGH PRESSURE WILL ONCE AGAIN BUILD ACROSS THE AREA. SAT MRNG
ANOTHER TROUGH WILL MOVE INTO NRN ME FROM THE NE. BY THE END OF
THE PERIOD THE GFS HAS THE TROUGH MOVING BACK NE ACROSS ERN
MAINE... THE ECMWF MOVES IT INTO SW MAINE.
DUE TO UNCERTAINTY IN THE EXTENDED PERIOD USED A BLEND OF THE
MODELS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. ADDED 15
PERCENT TO WINDS FOR GUSTS OVER LAND...25 PERCENT OVER THE COASTAL
WATERS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: 10PM UPDATE: 00Z TAFS REMAIN ON TRACK WITH VFR
CONDITIONS UNDER MOSTLY MID AND HIGH CLOUDS AS OF 02Z. NO CHANGE
TO REASONING SHOWING LOWERING CATEGORIES AS THE WEAK FRONT PUSHES
THRU OVERNIGHT INTO TOMORROW AM.
ORIGINAL DISCUSSION:
VFR THIS EVENING ACROSS THE NORTHERN TAF SITES DROPPING
TO MVFR LATER TONIGHT AND POSSIBLE IFR NORTH OF KHUL. S OF KHUL,
VFR THROUGH SUNDAY NIGHT. VFR CONDITIONS RETURN FOR NORTHERN AREAS
BY MIDDAY SUNDAY INTO SUNDAY NIGHT. IFR CONDITIONS POSSIBLE LATER
SUNDAY NIGHT W/FOG AND STRATUS AS SSW FLOW SETS UP.
SHORT TERM: A FEW LINGERING CLOUDS ACROSS NRN MAINE AT THE START OF THE
PERIOD OTHERWISE VFR THROUGH WED MRNG ALL SITES...MVFR WED MRNG
ACROSS FVE AND CAR...WED AFTERNOON PQI AND HUL...AND BGR AND BHB
WED EVNG...AS A TROUGH MOVES THROUGH...OTHERWISE VFR.
&&
.MARINE...
NEAR TERM: NO HEADLINES. A S SWELL IN PLACE ATTM W/10-11 SECOND
PERIOD. WAVE HEIGHTS WILL BUILD A BIT W/SW WIND PICKING UP TO 15
KTS EARLY SUNDAY ESPECIALLY OVER THE OUTER WATERS TO 3 FT. OVER
THE INTRA-COASTAL ZONES, 1-2 FT HOLDING W/10 KT WINDS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THROUGH THE PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HASTINGS/HEWITT/NORTON
MARINE...HASTINGS/HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS DULUTH MN
300 AM CDT SUN AUG 30 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 257 AM CDT SUN AUG 30 2015
ONE THE SHORT TERM CONCERNS WILL BE THE AMOUNT OF SMOKE OVER THE
REGION TODAY AND MONDAY AND HOW THAT IMPACTS TEMPERATURES. A WEAK
COLD FRONT WILL ALSO MOVE INTO WESTERN MINNESOTA MONDAY AFTERNOON
BRINGING A THREAT FOR SHOWERS/STORMS TO OUR WESTERN ZONES.
AN UPPER RIDGE WILL MOVE OVER THE NORTHLAND TODAY AND PASS TO THE
EAST TONIGHT INTO MONDAY MORNING. STRATUS AND FOG WERE EXPANDING
THIS MORNING AND THE RAP/HRRR BOTH SHOW THIS TREND CONTINUING
OVERNIGHT...THEN THINNING BY 18Z. A LOOK AT YESTERDAYS VISIBLE
SATELLITE SHOWED PLENTY OF SMOKE OVER THE NORTHERN/CENTRAL PLAINS
INTO PORTIONS OF MINNESOTA. WE ARE CONCERNED THAT WE WILL SEE ENOUGH
SMOKE TO LIMIT SUNSHINE TODAY. WE TRIMMED HIGHS A BIT TODAY THINKING
THE SMOKE WILL BE PRESENT AND WE ALSO BEEFED UP CLOUD COVER SINCE
SMOKE WILL GIVE THE APPEARANCE OF HIGH CLOUDS. IF THE SMOKE IS
THINNER THAN EXPECTED...HIGHS WILL HAVE TO BE BUMPED BACK UP. WE
HAVE HIGHS TODAY FROM THE UPPER SEVENTIES TO MIDDLE EIGHTIES.
WE EXPECT CLOUDS TO INCREASE MONDAY AHEAD OF THE COLD FRONT...AND
SOME SMOKE WILL ONCE AGAIN BE PRESENT. WE HAVE HIGHS FROM 80 TO 85
FOR MOST AREAS. THERE WILL ALSO BE A SLIGHT CHANCE FOR SOME
AFTERNOON SHOWERS/STORMS OVER WESTERN AREAS OF THE NORTHLAND.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 257 AM CDT SUN AUG 30 2015
WARM AND HUMID THROUGH THE FIRST WEEK OF SEPTEMBER WITH CHANCES FOR
AN ISOLATED STORM MOST DAYS. LITTLE CHANGE TO THE PREVIOUS FORECAST
WITH ABOVE NORMAL CONFIDENCE IN THE OVERALL PATTERN. STORM CHANCES
EACH DAY ARE FAIRLY LOW...WITH THE BEST CHANCE FOR WIDESPREAD
SHOWERS AND STORMS LATE IN THE WEEK INTO THE WEEKEND AS A COLD FRONT
MOVES THROUGH FROM WEST TO EAST.
ON THE SYNOPTIC SCALE A LONGWAVE TROUGH WILL DEEPEN IN THE WEST
WHILE A WEAK RIDGE DEVELOPS OVER THE EAST...RESULTING IN
SOUTHWESTERLY FLOW ALOFT FOR THE UPPER MIDWEST. THIS WILL PLACE THE
REGION WITHIN THE STORM TRACK FOR A FEW WEAK MID-LEVEL IMPULSES
THROUGH THE WEEK. AT THE SURFACE A WARM FRONT WILL LIFT NORTH ACROSS
THE REGION ON WEDNESDAY INTO WEDNESDAY NIGHT...AND FOLLOWING THIS
STORM COVERAGE WILL LIKELY BE LIMITED THURS/FRI AFTERNOON UNTIL
FRIDAY NIGHT AND THROUGH THE WEEKEND AS A COLD FRONT MOVES THROUGH
FROM WEST TO EAST. AHEAD OF THE FRONT WINDS WILL BE BREEZY OUT OF
THE SOUTH...WITH A VERY HUMID WARM SECTOR IN PLACE AS DEW POINTS
RISE TO NEAR 70. STORMS THIS WEEKEND COULD HAVE THE POTENTIAL TO BE
STRONG TO SEVERE DUE TO FAIRLY STEEP MID-LEVEL LAPSE RATES WHICH
WILL AIDE IN INSTABILITY AND STRONGER MID/UPPER LEVEL WINDS LEADING
TO BETTER DEEP LAYER SHEAR. NOT CONFIDENT ENOUGH TO MENTION THIS IN
THE HWO JUST YET...BUT SHOULD THE RIGHT FACTORS ALIGN THIS IS A
POSSIBILITY.
HIGHS THROUGH THE WEEK AND INTO THE WEEKEND IN THE LOW TO MID
80S...EXCEPT FOR 70S BY LAKE SUPERIOR. LOWS IN THE MID 50S TO LOW
60S ON NIGHTS WHEN SKIES CLEAR...OTHERWISE IN THE MID TO UPPER 60S
DUE TO CLOUD COVER. WINDS PREDOMINATELY OUT OF THE SOUTH...BECOMING
GUSTY ON THURSDAY FRIDAY AND EVEN SATURDAY AHEAD OF THE COLD
FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1232 AM CDT SUN AUG 30 2015
MOISTURE WILL RACE NORTH TO NORTHEAST ACROSS THE NORTHLAND
OVERNIGHT...AS A SOUTHERLY LLJ DEVELOPS ACROSS THE CENTRAL PORTION
OF THE COUNTRY. THE HRRR AND RAP CONTINUE TO INDICATE THAT LOW
CLOUDS AND FOG WILL HIT THE SOUTHEAST HALF OF THE FORECAST AREA THE
HARDEST...WITH IFR/LIFR CONDITIONS DEVELOPING OVERNIGHT. THERE IS A
BIT LOWER CONFIDENCE FOR KHIB AND KINL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 81 64 84 64 / 0 10 10 30
INL 85 64 84 55 / 0 10 20 20
BRD 83 65 85 60 / 0 10 10 20
HYR 80 62 83 65 / 0 0 0 20
ASX 84 63 86 65 / 0 0 0 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...JJM
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
1233 AM CDT SUN AUG 30 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 309 PM CDT SAT AUG 29 2015
HAVING A HARD TIME GETTING RID OF THE CLOUDS ACROSS THE FORECAST
AREA TODAY. LOOKS LIKE A UPPER LEVEL VORTICITY CENTER HAS BEEN
ROTATING THROUGH THE UPPER RIDGE..KEEPING CLOUDS OVER THE
NORTHLAND. BY SUNDAY MORNING WE SHOULD BE GRADUALLY CLEARING THE
CLOUDS AS THE UPPER RIDGING TAKES OVER. THERE WILL LIKELY B
MORNING CLOUDS...SIMILAR TO TODAY...BUT MIXING AND SUBSIDENCE SHOULD
HELP CLEAR OUT THE CLOUDS. VERY STRONG WARM AIR ADVECTION WILL
KEEP TEMPERATURES WARM OVERNIGHT...THEN VERY WARM TO HOT TOMORROW.
AND THE RETURN FLOW WILL ALSO BRING IN MORE HUMID AIR WITH
DEW POINTS IN THE MID TO UPPER 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 309 PM CDT SAT AUG 29 2015
THE RIDGE PULLS OFF TO THE EAST AS SKIES WILL BE PARTLY CLOUDY
ACROSS THE REGION. A SURFACE TROUGH WILL DEVELOP UNDER A LONGWAVE
TROUGH SUNDAY NIGHT AND MOVE SLOWLY THROUGH NORTHERN/CENTRAL PLAINS
AND GREAT LAKES REGION ON MONDAY AND TUESDAY MORNING. ALSO...A
SOUTHERLY FLOW AHEAD OF THE TROUGH WILL PUSH WARMER AND MORE HUMID
AIR INTO THE FORECAST REGION. THERE WILL BE A BREAK IN THE PRECIP
CHANCES TUESDAY NIGHT AND WEDNESDAY MORNING AS A WEAK AREA OF HIGH
PRESSURE MOVES THROUGH THE REGION. A WARM FRONT WILL MOVE NORTH
INTO THE FORECAST AREA LATER WEDNESDAY KEEPING THE WARM AND HUMID
CONDITIONS ACROSS THE AREA. WEAK SHORTWAVES WILL PASS THROUGH THE
REGION WEDNESDAY NIGHT THROUGH FRIDAY MORNING KEEPING THE CHANCE OF
SCATTERED THUNDERSTORMS. A COLD FRONT WILL MOVE THROUGH THE
FORECAST AREA FRIDAY AFTERNOON THROUGH SATURDAY BRINGING WIDESPREAD
CONVECTION VERSUS SCATTERED EARLIER IN THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1232 AM CDT SUN AUG 30 2015
MOISTURE WILL RACE NORTH TO NORTHEAST ACROSS THE NORTHLAND
OVERNIGHT...AS A SOUTHERLY LLJ DEVELOPS ACROSS THE CENTRAL PORTION
OF THE COUNTRY. THE HRRR AND RAP CONTINUE TO INDICATE THAT LOW
CLOUDS AND FOG WILL HIT THE SOUTHEAST HALF OF THE FORECAST AREA THE
HARDEST...WITH IFR/LIFR CONDITIONS DEVELOPING OVERNIGHT. THERE IS A
BIT LOWER CONFIDENCE FOR KHIB AND KINL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 63 84 64 82 / 0 0 30 20
INL 63 84 60 82 / 10 20 30 10
BRD 65 85 64 85 / 10 10 30 20
HYR 62 84 65 83 / 0 0 10 20
ASX 62 84 65 84 / 0 0 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...CLC
LONG TERM...MRS
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
200 AM PDT SUN AUG 30 2015
.SYNOPSIS...A BROAD LOW PRESSURE TROUGH MOVING INTO THE GREAT BASIN
AND MOJAVE DESERT REGION WILL BRING DRY SOUTHWEST FLOW WITH COOLER
AND BREEZY CONDITIONS THROUGH THE COMING WEEK AND INTO THE LABOR DAY
WEEKEND. SLIGHT CHANCES FOR THUNDERSTORMS WILL REMAIN IN EASTERN
MOHAVE COUNTY WITH ACTIVITY DECREASING THROUGH TUESDAY.
&&
.SHORT TERM...TONIGHT THROUGH TUESDAY.
A SOUTHWESTERLY FLOW HAS TAKEN HOLD OF THE REGION IN RESPONSE TO
TROUGHING ACROSS THE PACIFIC NORTHWEST AND HIGH PRESSURE SHUNTED
SOUTHWARD INTO NORTHERN MEXICO. THIS HAS RESULTED IN THE MOIST
MONSOONAL FLOW BEING SUBDUED AND PUSHED MORE INTO ARIZONA LEAVING
MOST OF OUR FORECAST AREA HIGH AND DRY FOR THE FORESEEABLE FUTURE.
ONLY CAVEAT TO THAT WILL BE ACROSS EASTERN MOHAVE COUNTY THE NEXT
COUPLE AFTERNOONS WHERE SOME MARGINAL INSTABILITY WILL REMAIN IN
PLACE TO SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY THE
HIGHER TERRAIN. EARLY MORNING RUNS OF THE HRRR SUPPORT THIS AGAIN
FOR THIS AFTERNOON...PARTICULARLY NORTH OF THE I-40 CORRIDOR IN
EASTERN MOHAVE COUNTY...AND HAVE MAINTAINED POPS FOR THOSE AREAS
THIS AFTERNOON.
ELSEWHERE...SOME PERIODS OF HIGH CLOUDS CAN BE EXPECTED BUT NOTHING
OVERLY SUBSTANCIAL. HIGH TEMPERATURES WILL CREEP DOWNWARD THROUGH
TUESDAY BUT SHOULD REMAIN SLIGHTLY ABOVE NORMAL THROUGH
MONDAY...BEFORE RETURNING TO NEAR NORMAL ON TUESDAY.
.LONG TERM...WEDNESDAY THROUGH SUNDAY.
NUMEROUS SHORTWAVES WILL MOVE THROUGH A LONGWAVE TROUGH WHICH WILL
REMAIN OVER THE PAC NW/NRN ROCKIES DURING MUCH OF THE PERIOD. THIS
WILL KEEP THE SOUTHERN GREAT BASIN/MOJAVE DESERT UNDER A SOUTHWEST
FLOW. LOOK FOR BREEZY TO LOCALLY WINDY AFTERNOON/EVENING HOURS WITH
SLIGHTLY BELOW NORMAL TEMPERATURES.
SOMETHING TO MONITOR WILL BE THE POTENTIAL DEVELOPMENT OF A TROPICAL
SYSTEM IN THE EASTERN PACIFIC. BOTH THE GFS/ECMWF DEVELOP A SYSTEM
WELL SOUTHWEST OF CABO SAN LUCAS WEDNESDAY. THE FEATURE MOVES NORTH
BUT LOOKS TO GET SHEARED APART WEST OF THE BAJA PENINSULA FRIDAY
WITH REMNANT MID LEVEL ENERGY GETTING CAUGHT IN THE SOUTHWEST FLOW
AND MOVING OVER ARIZONA SATURDAY. THE ASSOCIATED MOISTURE BEARS
WATCHING AS SOME OF IT MAY GET PULLED NORTHWARD UP THE COLORADO
RIVER AND INTO WESTERN ARIZONA SATURDAY NIGHT OR SUNDAY.
&&
.AVIATION...FOR MCCARRAN...FAIR WEATHER EXPECTED TODAY WITH PERIODS
OF PASSING HIGH CLOUDS. SOUTHWESTERLY WINDS EXPECTED MOST OF THE DAY
WITH SPEEDS OF 12-20 KTS WITH GUSTS TO 25 KTS. WHILE
UNLIKELY...THERE IS A SMALL POSSIBILITY OF A PERIOD OF SOUTHEAST
WINDS BETWEEN 15Z-18Z. WIND GUSTS WILL DECREASE AFTER SUNSET.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...FAIR WEATHER EXPECTED WITH ONLY SLIGHT CHANCES FOR
THUNDERSTORMS IN FAR EASTERN MOHAVE COUNTY. ELSEWHERE..JUST PASSING
HIGH CLOUDS EXPECTED WITH AREAS OF SMOKE IN THE OWENS VALLEY AND
NEAR KBIH. BREEZY SOUTHWEST WINDS OF 15-20KT WITH GUSTS TO 30KTS
EXPECTED IN THE AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION WILL NOT BE
NECESSARY. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...OUTLER
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 NORMAN OK
406 AM CDT SUN AUG 30 2015
.DISCUSSION...
MAIN ADJUSTMENT TO GOING FORECAST PACKAGE WAS TO ADD FOG FOR THIS
MORNING ACROSS AREAS NORTH OF I-40. THE MOST WIDESPREAD AND
POSSIBLY DENSE FOG WILL BE OVER FAR NORTH/NORTHWEST OKLAHOMA
NEAREST LOW LEVEL RIDGE AXIS. CONFIDENT THAT THERE WILL BE FOG BUT
JUST NOT SURE HOW WIDESPREAD ANY DENSE FOG WILL BE. THE MOST
AGGRESSIVE MODELS...WRF AND HRRR KEEP A MAJORITY OF DENSE FOG UP
IN KANSAS THROUGH 9 AM. DENSE FOG ADVISORY NOT ANTICIPATED AT THIS
POINT BUT WE WILL WATCH TRENDS AND ISSUE AS NEEDED. POPS WERE ALSO
CONTINUED THROUGH TODAY ACROSS SOUTHEAST CWA NEAR MID-LEVEL SHEAR
AXIS AND EFFECTIVE SYNOPTIC BOUNDARY.
TODAYS TEMPS WERE COOLED A BIT FROM PREVIOUS FORECAST AS WELL.
INITIALIZATIONS CAME IN A FEW DEGREES COOLER MAINLY OVER NORTHERN
AND WESTERN OKLAHOMA...AND WITH PLUME OF HIGH LEVEL SMOKE THIS
SOUNDS REASONABLE. GFS AND ECM HAVE TRENDED WEAKER WITH THE UPPER
LEVEL RIDGE AND HAVE GENERALLY UNDERFORECAST STRENGTH/PERSISTENCE
OF LONGWAVE TROUGH AXIS JUST TO OUR EAST. THIS WILL YIELD SLIGHTLY
COOLER TEMPS THROUGH THE WEEK MOST AREAS AND ALTHOUGH POPS ARE TOO
LOW TO MENTION...CANNOT RULE OUT AN ISOLATED SHOWER OR WEAK STORM
ESPECIALLY FAR NORTHWEST OKLAHOMA CLOSER TO POSSIBLE HIGH PLAINS
REMNANTS AND FAR SOUTHEAST OKLAHOMA CLOSER TO UPPER TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 93 70 / 0 0 0 0
HOBART OK 92 67 97 71 / 0 0 0 0
WICHITA FALLS TX 96 71 97 72 / 10 0 0 0
GAGE OK 91 63 96 69 / 0 0 0 0
PONCA CITY OK 88 67 93 70 / 0 0 0 0
DURANT OK 94 71 95 71 / 20 10 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/11
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
411 AM EDT SUN AUG 30 2015
.SYNOPSIS...
INCREASING MOISTURE WILL BE CHANNELED NORTHEAST FROM THE OHIO
VALLEY TODAY...AND INTERACT WITH A STATIONARY FRONTAL BOUNDARY TO
PRODUCE SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS MAINLY
THE NORTHWESTERN HALF OF THE STATE. HIGH PRESSURE OFF THE MID
ATLANTIC COAST WILL BE MORE INFLUENTIAL ON KEEPING FAIR AND DRY
WEATHER INTACT ACROSS THE SOUTHEASTERN HALF OF PENNSYLVANIA.
VERY WARM AND INCREASINGLY HUMID WEATHER WILL CONTINUE INTO THE
MIDDLE OF THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STABLE STRATIFICATION UNDER CLEAR TO PTLY CLOUDY SKIES WILL
CONTINUE ACROSS MUCH OF CENTRAL AND SOUTHERN PENN THROUGH THE MID
MORNING HOURS. OVER NWRN PENN.
SFC BASED CAPE WILL SLOWLY INCREASE TO BETWEEN 300-500 J/KG
ACROSS THE NW MTNS THIS MORNING WITH THE ADVECTION OF 1.5 INCH
PWAT AIR FROM THE OHIO VALLEY. THE PRESENCE OF A QUASI-STNRY
FRONTAL BOUNDARY AND THE INCREASING MOISTURE FROM THE OHIO
VALLEY...WILL LEAD TO NEWRD EXPANSION OF SHOWERS AND A FEW
ISOLATED TSRA EARLY TODAY.
PATCHY LIGHT RIVER VALLEY FOG EXPECTED ELSEWHERE AS SFC DEWPOINTS
SLOWLY RISE.
MIN TEMPS SHOULD RANGE FROM THE MID TO UPPER 50S OVER THE NORTH...
TO THE LOWER 60S IN THE SOUTHEAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME EARLY MORNING FOG IN THE VALLEYS - WHICH SHOULD BE OF LESSER
COVERAGE THAN SAT MORNING. THEN...THE TEMPS RISE EVEN
BETTER...ADDING ANOTHER 3-4F ONTO SAT/S MAXES.
RIDGE AT THE SFC AND ALOFT IS STARTING TO GET PRESSED A LITTLE TO
THE EAST BY AN ADVANCING UPPER TROUGH AND SLIGHT FEED OF GULF
MOISTURE. THUS...SUPPORT IN THE FORM OF INSTABILITY AND MOISTURE
WILL BE AVAILABLE TODAY.
PLAN TO INCREASE POPS INTO THE LIKELY CATEGORY ACROSS THE NW MTNS
DURING THE MID TO LATE MORNING HOURS. THERE WILL BE A TRANSITION
TO VIRTUALLY NO CHC OF RAIN OVER THE SE COUNTIES OF OUR CWA.
CONVECTIVE ALLOWING HRRR MODEL SUGGEST EVEN CATEGORICAL ARE
WARRANTED ACROSS PARTS OF THE NW AND NCENT MTNS /AND EVEN FOR A
MORE BRIEF TIME PERIOD OF A FEW HOURS OVER THE LAUREL HIGHLANDS
CENTERED ON DAYBREAK/. THIS SECOND...AND MORE SIGNIFICANT CLUSTER
OF CONVECTION WILL IMPACT THE NW MTNS OF PENN BETWEEN 10-14Z.SOME
LOCATIONS WILL SEE BETWEEN 0.25 AND 0.50 INCH OF RAIN...WHERE TWO
OR MORE MDT-HVY SHOWERS OCCUR.
AFTER THE INITIAL...RATHER COMPACT SHORTWAVE ALOFT LIFTS INTO
SOUTHCENTRAL NEW YORK LATER THIS MORNING...THE ATMOS WILL RECHARGE
TO OVER 1000 J/KG CAPE IN SOME AREAS...AND BE CAPABLE OF FIRING
OFF SCTD SHRA/TSRA ACROSS THE CENTRAL MTNS...AND ALLEGHENIES THIS
AFTERNOON.
HIGHS THIS AFTERNOON WILL VARY FROM THE U70S ACROSS THE NRN AND
WRN MTNS...TO THE UPPER 80S ACROSS THE LOWER SUSQ VALLEY AND
SURROUNDING AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH 850HPA
TEMPS RUNNING 16-18C WHICH WILL TRANSLATE TO WELL ABOVE-NORMAL
SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR
AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT THE
PROBABILITY OF WIDESPREAD RAINFALL IS LOW.
THERE ARE A COUPLE OF INTERESTING FEATURES THAT BEAR WATCHING FOR
LATE IN THE LONG TERM PERIOD. THE FIRST IS THE REMNANTS OF
ERIKA...WHICH ARE FCST TO BE IN THE VICINITY OF THE FL/GA COAST BY
THE MIDDLE OF NEXT WEEK. AS THIS MOISTURE DIFFUSES OVER THE
SOUTHEAST U.S....SOME OF IT WILL GRADUALLY CRAWL INTO THE MID
ATLANTIC REGION. THE OTHER INTERESTING FEATURE IS A BACKDOOR COLD
FRONT THAT SOME MODELS BRING INTO THE MID-ATLANTIC STATES NEXT
THURS/FRI. THESE FEATURES COMBINED WITH THE WARM AND INCREASINGLY
HUMID AIR THAT WILL ALREADY BE IN PLACE WILL KEEP MENTION OF AT
LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY. THE LATTER
FEATURE COULD HAVE AN IMPACT ON TEMPS LATE NEXT WEEK...TAPERING
BACK TEMPS A BIT.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
CONVECTION OUT AHEAD OF AN APPROACHING TROUGH IS CURRENTLY
STREAMING THROUGH NORTHWEST PA...AND SHOULD ALLOW FOR SOME LIGHT
SHOWERS BRINGING POSSIBLE MVFR CIGS/VSBYS TO BFD. OTHERWISE PATCHY
AREAS OF FOG MAINLY MVFR WITH SOME ISOLATED AREAS OF IFR. THOUGH
GENERALLY LIGHT WINDS...ANY REGION THAT DECOUPLES SHOULD SEE
INCREASE FOG FORMATION. IFR CONDITIONS HAVE THE HIGHEST CHANCE AT
UNV...AOO AND BFD.
CONSIDERING THE SHORT RANGE MODELS...EXPECT A HIGH CHANCE FOR
SHOWERS ACROSS NORTHERN PENNSYLVANIA THIS MORNING. BY 16Z SHOWERS
MOVE INTO SOUTHWEST MOUNTAINS. USED MAINLY VCSH/VCTS TO HANDLE
SHOWERS AS THE PROBABILITIES ARE GENERALLY 20 TO 40 PERCENT.
HIGHEST PROBABILITIES OF SHOWERS/THUNDER IN NORTHWEST.
OUTLOOK...
MON...STILL SOME SHRA/TSRA POSS.
TUE-THU...NO SIG WX EXPECTED AREAS MVFR OVERNIGHT PATCHY FOG.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...GRUMM/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
153 AM EDT SUN AUG 30 2015
.SYNOPSIS...
INCREASING MOISTURE WILL BE CHANNELED NORTHEAST FROM THE OHIO
VALLEY TODAY...AND INTERACT WITH A STATIONARY FRONTAL BOUNDARY TO
PRODUCE SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS MAINLY
THE NORTHWESTERN HALF OF THE STATE. HIGH PRESSURE OFF THE MID
ATLANTIC COAST WILL BE MORE INFLUENTIAL ON KEEPING FAIR AND DRY
WEATHER INTACT ACROSS THE SOUTHEASTERN HALF OF PENNSYLVANIA.
VERY WARM AND INCREASINGLY HUMID WEATHER WILL CONTINUE INTO THE
MIDDLE OF THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STABLE STRATIFICATION UNDER CLEAR TO PTLY CLOUDY SKIES WILL
CONTINUE ACROSS MUCH OF CENTRAL AND SOUTHERN PENN THROUGH THE MID
MORNING HOURS. OVER NWRN PENN.
SFC BASED CAPE WILL SLOWLY INCREASE TO BETWEEN 300-500 J/KG
ACROSS THE NW MTNS THIS MORNING WITH THE ADVECTION OF 1.5 INCH
PWAT AIR FROM THE OHIO VALLEY. THE PRESENCE OF A QUASI-STNRY
FRONTAL BOUNDARY AND THE INCREASING MOISTURE FROM THE OHIO
VALLEY...WILL LEAD TO NEWRD EXPANSION OF SHOWERS AND A FEW
ISOLATED TSRA EARLY TODAY.
PATCHY LIGHT RIVER VALLEY FOG EXPECTED ELSEWHERE AS SFC DEWPOINTS
SLOWLY RISE.
MIN TEMPS SHOULD RANGE FROM THE MID TO UPPER 50S OVER THE NORTH...
TO THE LOWER 60S IN THE SOUTHEAST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
SOME EARLY MORNING FOG IN THE VALLEYS - WHICH SHOULD BE OF LESSER
COVERAGE THAN SAT MORNING. THEN...THE TEMPS RISE EVEN
BETTER...ADDING ANOTHER 3-4F ONTO SAT/S MAXES.
RIDGE AT THE SFC AND ALOFT IS STARTING TO GET PRESSED A LITTLE TO
THE EAST BY AN ADVANCING UPPER TROUGH AND SLIGHT FEED OF GULF
MOISTURE. THUS...SUPPORT IN THE FORM OF INSTABILITY AND MOISTURE
WILL BE AVAILABLE TODAY.
PLAN TO INCREASE POPS INTO THE LIKELY CATEGORY ACROSS THE NW MTNS
DURING THE MID TO LATE MORNING HOURS. THERE WILL BE A TRANSITION
TO VIRTUALLY NO CHC OF RAIN OVER THE SE COUNTIES OF OUR CWA.
CONVECTIVE ALLOWING HRRR MODEL SUGGEST EVEN CATEGORICAL ARE
WARRANTED ACROSS PARTS OF THE NW AND NCENT MTNS /AND EVEN FOR A
MORE BRIEF TIME PERIOD OF A FEW HOURS OVER THE LAUREL HIGHLANDS
CENTERED ON DAYBREAK/. THIS SECOND...AND MORE SIGNIFICANT CLUSTER
OF CONVECTION WILL IMPACT THE NW MTNS OF PENN BETWEEN 10-14Z.SOME
LOCATIONS WILL SEE BETWEEN 0.25 AND 0.50 INCH OF RAIN...WHERE TWO
OR MORE MDT-HVY SHOWERS OCCUR.
AFTER THE INITIAL...RATHER COMPACT SHORTWAVE ALOFT LIFTS INTO
SOUTHCENTRAL NEW YORK LATER THIS MORNING...THE ATMOS WILL RECHARGE
TO OVER 1000 J/KG CAPE IN SOME AREAS...AND BE CAPABLE OF FIRING
OFF SCTD SHRA/TSRA ACROSS THE CENTRAL MTNS...AND ALLEGHENIES THIS
AFTERNOON.
HIGHS THIS AFTERNOON WILL VARY FROM THE U70S ACROSS THE NRN AND
WRN MTNS...TO THE UPPER 80S ACROSS THE LOWER SUSQ VALLEY AND
SURROUNDING AREAS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH 850HPA
TEMPS RUNNING 16-18C WHICH WILL TRANSLATE TO WELL ABOVE-NORMAL
SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR
AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT THE
PROBABILITY OF WIDESPREAD RAINFALL IS LOW.
THERE ARE A COUPLE OF INTERESTING FEATURES THAT BEAR WATCHING FOR
LATE IN THE LONG TERM PERIOD. THE FIRST IS THE REMNANTS OF
ERIKA...WHICH ARE FCST TO BE IN THE VICINITY OF THE FL/GA COAST BY
THE MIDDLE OF NEXT WEEK. AS THIS MOISTURE DIFFUSES OVER THE
SOUTHEAST U.S....SOME OF IT WILL GRADUALLY CRAWL INTO THE MID
ATLANTIC REGION. THE OTHER INTERESTING FEATURE IS A BACKDOOR COLD
FRONT THAT SOME MODELS BRING INTO THE MID-ATLANTIC STATES NEXT
THURS/FRI. THESE FEATURES COMBINED WITH THE WARM AND INCREASINGLY
HUMID AIR THAT WILL ALREADY BE IN PLACE WILL KEEP MENTION OF AT
LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY. THE LATTER
FEATURE COULD HAVE AN IMPACT ON TEMPS LATE NEXT WEEK...TAPERING
BACK TEMPS A BIT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SOME WEAK SHOWERS WILL MOVE ACROSS NORTHWESTERN PA BETWEEN 03 AND
06Z. VCTS IN KBFD. OTHERWISE PATCHY AREAS OF FOG MAINLY MVFR SOME
ISOLATED ARE IFR. MODELS SHOWS COULD BE SOME ISOLATED SHOWERS
BEFORE SUNRISE IN FAR WEST.
MOST MODELS SHOW HIGHEST CHANCE OF SHOWER ACROSS NORTHERN
PENNSYLVANIA SUNDAY IN THE MORNING. BY 16Z SHOWERS MOVE INTO
SOUTHWEST MOUNTAINS. USED MAINLY VCSH/VCTS TO HANDLE SHOWERS AS
THE PROBABILITIES ARE GENERALLY 20 TO 40 PERCENT. HIGHEST
PROBABILITIES OF SHOWERS/THUNDER IN NORTHWEST. KBFD WILL LIKELY
SEE A SHOWER SUNDAY.
OUTLOOK...
MON...STILL SOME SHRA/TSRA POSS.
TUE-THU...NO SIG WX EXPECTED AREAS MVFR OVERNIGHT PATCHY FOG.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...RXR
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
341 AM CDT SUN AUG 30 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT SUN AUG 30 2015
MOST IMMEDIATE CONCERN IS PATCHY DENSE FOG EARLY THIS MORNING.
BECAUSE NOT ALL LOW CLOUD FROM YESTERDAY DISSIPATED AND THE FACT
THAT 0.5 KM SOUTHWEST WINDS ARE INCREASING FROM NOW UNTIL
SUNRISE...WIDESPREAD DENSE FOG IS IN QUESTION. THERE HAVE BEEN
SOME SITES ACROSS THE REGION THAT HAVE REPORTED ONE-HALF MILE OR
LESS IN FOG...BUT NOT CONSISTENTLY AS VISIBILITY GOES UP AND DOWN
OVER RELATIVELY SHORT PERIODS. FOR NOW...WILL COVER FOG THREAT
WITH A SPS...BUT MONITOR CAREFULLY FOR MORE WIDESPREAD PERSISTENT
LOW VISIBILITY THAT COULD NECESSITATE AN ADVISORY.
WHETHER STRATUS OF FOG...MOST AREAS SHOULD WAKE UP TO GRAY/FOGGY
SKIES. HOWEVER...LOW-LEVEL MOISTURE SHOULD BEGIN TO MIX OUT AFTER
SUNRISE AS BOUNDARY LAYER DEEPENS TO BETWEEN 1500 AND 2000 FT BY
MIDDAY. SHOULD FINALLY BEGIN TO SEE A FAIR AMOUNT OF SUN BY EARLY
TO MID AFTERNOON. WITH A SLOW START TO WARMING FOR THE DAY...
DROPPED TEMPERATURES A FEW DEGREES WITH HIGHS NOW EXPECTED IN THE
MID TO UPPER 70S. FOR AREAS THAT SEE A BIT MORE SUN...HIGHS MAY
WARM INTO THE LOWER 80S.
EXPECT MOSTLY CLEAR SKIES TONIGHT WITH LIGHT SOUTHERLY WINDS. WILL
KEEP PATCHY VALLEY/BOG FOG MENTION...BUT ITS OCCURRENCE IS A BIT
LESS CERTAIN. MODEL SOUNDINGS SHOWING NEAR SURFACE SATURATION...
BUT ALSO 15 TO 20 KTS IMMEDIATELY ABOVE THE NOCTURNAL INVERSION.
THIS SET-UP MAY BE MORE FAVORABLE FOR LOW STRATUS THAN FOG...BUT
SOMETHING TO WATCH. LOWS TONIGHT WILL DROP INTO THE 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 341 AM CDT SUN AUG 30 2015
MONDAY THROUGH WEDNESDAY...500 HPA RIDGE MOVES INTO THE EASTERN
CONUS...ALTHOUGH PERHAPS A BIT FLATTER THAN PREVIOUSLY FORECAST
GIVEN WEAK SHORT-WAVES MOVING THROUGH SOUTHWEST FLOW ALOFT. MAIN
IMPACT WILL BE WARMING TEMPERATURES WITH DAILY HIGHS IN THE 80S...
ALTHOUGH SOME VALLEY LOCATIONS COULD APPROACH 90 DEGREES GIVEN
FAVORABLE SOUTH-SOUTHWEST SURFACE WIND. RIDGE AXIS RETROGRADES
BACK ACROSS THE SOUTHERN PLAINS FOR LATE IN THE WEEK...RESULTING
IN THUR/FRI/SAT POSSIBLY BEING THE WARMEST DAYS OF THE WEEK WITH
MANY LOCATIONS INTO THE UPPER 80S...PERHAPS 90 DEGREES.
WILL KEEP PERIODIC 20-30 POPS THROUGH THE WEEK...ALTHOUGH THINK
DRY CONDITIONS WILL BE THE RULE SINCE AXIS OF MAXIMUM MID-LEVEL
MOISTURE TRANSPORT REMAINS MAINLY WEST OF THE FORECAST AREA AND
DEEP LAYER SHEAR IS WEAK. BEST CHANCE FOR MORE WIDESPREAD SHOWERS
AND THUNDERSTORMS HOLDS OFF UNTIL LATE SATURDAY INTO SUNDAY AS
EASTERN PACIFIC TROUGH/COLD FRONT FINALLY PUSH FAR ENOUGH EAST TO
IMPACT THE UPPER MS RIVER VALLEY. WILL INTRODUCE HIGH END CHANCE
POPS FOR THIS PERIOD. WITH CLOUDS/POSSIBLE RAIN AND APPROACHING
COLD FRONT...COULD SEE TEMPERATURES BEGIN TO RETREAT AS EARLY AS
NEXT SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1130 PM CDT SAT AUG 29 2015
VERY CHALLENGING FORECAST.
FOG...STRATUS...OR BOTH REMAINS THE QUESTION AND LATEST MODELS RUNS
AND TRENDS AREN/T GIVING MUCH CONFIDENCE ONE WAY OR THE OTHER. THAT
SAID - THE IMPACTS ON AVIATION COULD BE THE SAME AS FLIGHT
CATEGORIES FROM FOG OR LOW STRATUS COULD BE THE SAME.
LOW STRATUS HAS BEEN RELUCTANT TO EXIT THE AREA AT LATE
EVENING...SLOWING DOWN/STOPPING. THERE ARE EVEN SOME HINTS OF
NORTHWARD DEVELOPMENT OVER NORTHERN IA. RAP MODEL SUGGEST THIS WILL
OCCUR IN EARNEST...WITH LOW CIGS SPREADING OVER SOUTHERN MN
OVERNIGHT. KLSE WOULD HOLD STEADY OR DROP A BIT IN HEIGHTS...BUT
LIKELY STAY IFR.
IF THE STRATUS DOES NOT ADVANCE INTO KRST...FOG IS THE LIKELY
OUTCOME...AND SUB 1SM IS A POSSIBILITY. SOME LOCATIONS ACROSS
SOUTHERN MN/NORTHERN IA ALREADY HAVE VSBY RESTRICTIONS. IF THE
STRATUS HOLDS AT KLSE...THE IMPACT ON VSBYS WILL NOT BE AS EXTREME AS
FIRST FORECAST.
CONFIDENCE IS HIGH IN CIGS AND/OR FOG IMPACTS AT KRST/KLSE OVERNIGHT
THROUGH MOST OF SUN MORNING. WHICH ONE IS MORE DOMINANT IS WHERE THE
CONFIDENCE IS SHAKY. GOING TO STAY THE COURSE AS A RESULT...HOLDING
WITH THE PREVIOUS FORECAST FOR THE MOST PART. EXPECT UPDATES
OVERNIGHT AS CONFIDENCE INCREASES IN THE MORE LIKELY OUTCOME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1130 PM CDT SAT AUG 29 2015
.SHORT TERM...(TONIGHT THRU SUNDAY NIGHT)
ISSUED AT 237 PM CDT SAT AUG 29 2015
MAIN FCST CONCERNS THIS PERIOD...LATE NIGHT/EARLY MORNING
RADIATIONAL FOG POTENTIAL...TEMPERATURES.
18Z DATA ANALYSIS HAD LOW PRESSURE OVER SOUTHEAST IA/NORTHWEST IL
AND OVER CENTRAL SASKAT. WEAK HIGH PRESSURE EXTENDED FROM EASTERN
NEB TO NORTHERN WI/LOWER MI BETWEEN THEM. WV IMAGERY SHOWED
SHORTWAVE ENERGY AND A SECONDARY TROUGH AXIS DROPPING ACROSS IA AND
SOUTHEAST WI...WITH SUBSIDENCE/RISING HGTS SPREADING ACROSS MN/WI
BEHIND IT. SUBSIDENCE WAS STRENGTHENING AN INVERSION NEAR 925MB...
HELPING TO TRAP LOWER LEVEL MOISTURE/CLOUDS ACROSS MUCH OF THE
SOUTHEAST HALF OF THE UPPER MIDWEST. CLOUDS SLOWLY ERODING ACROSS
SOUTHERN MN/CENTRAL WI WITH DIURNAL WARMING/MIXING AND SOME WEAK SFC-
925MB ANTICYCLONIC FLOW. STUBBORN CLOUDS HOLDING TEMPS DOWN WITH
WARMEST TEMPS ACROSS THE REGION ONCE AGAIN OVER THE NORTHWEST HALF
OF MN WITH SOME SUNSHINE.
NO BIG PROBLEMS NOTED WITH 29.12Z MODEL INITIALIZATIONS. SOLUTIONS
TRENDING TOWARD A TIGHTER CONSENSUS AS HGTS RISE/RIDGING ALOFT
BUILDS INTO THE UPPER MIDWEST TONIGHT/SUN...THEN AS HGTS FALL A BIT
AHEAD OF A STRONGER SHORTWAVE TROUGH MOVING INTO WESTERN ND BY 12Z
MON. TREND IS TOWARD A COMPROMISE OF THE EARLY RUNS WITH THE RIDGING
OVER THE REGION AND TOWARD STRONGER OF EARLIER RUNS ON THE SHORTWAVE
INTO WESTERN ND LATE SUN NIGHT. WITH THE TIGHTER CONSENSUS...SHORT
TERM FCST CONFIDENCE IS GENERALLY GOOD THIS CYCLE.
FOR THE SHORT TERM...LOWER CLOUDS/MOISTURE TRAPPED IN WEAK FLOW
UNDER A MDT/STRONG INVERSION NEAR 925MB PROVING PROBLEMATIC.
STRENGTHENING THE INVERSION ABOVE 925MB MAKING THE LOW CLOUD
LAYER MORE RESISTANT TO MIXING/EROSION. DIURNAL WARMING/MIXING
WAS WORKING ON IT THIS AFTERNOON...THOUGH MUCH SLOWER THAN EARLIER
EXPECTED. CLOUD COVER HAS BEEN INCREASED OVER MUCH OF THE FCST
AREA THRU THE EVENING...ESPECIALLY OVER THE SOUTHEAST HALF.
REMAINED OPTIMISTIC WITH A DECREASE OF CLOUDS THRU THE LATE
EVENING...EVEN AS WINDS BECOMING QUITE LIGHT /LESS THAN 5 TO
10KTS/ THRU 700MB BY/AFTER MIDNIGHT. CLOUDS AND HOW LONG THEY STAY
TONIGHT WILL HAVE IMPACTS ON THE RADIATIONAL FOG DEVELOPMENT.
STRONG SIGNAL AMONG ALL MODELS FOR WIDESPREAD FOG LATE TONIGHT
INTO SUN MORNING. EARLIER CLEARING WOULD ALLOW FOR MORE
WIDESPREAD FOG...WITH GREATER POTENTIAL/COVERAGE OF DENSE FOG
BETWEEN 09-14Z SUN. SLOWER CLEARING/LINGERING LOW CLOUDS TONIGHT
WOULD KEEP THE FOG MORE PATCHY WITH THE FOG /SOME DENSE/ MAINLY IN
THE RIVER VALLEYS. WILL LEAVE THE FOG GRIDS TONIGHT AS IS WITH
AREAS/WIDESPREAD IN THE VALLEYS/MORE FOG PRONE AREAS AND PATCHY
ELSEWHERE. HOWEVER DID EXPAND AT LEAST SOME PATCHY FOG MENTION IN
TIME FROM 05Z-15Z. DUE TO THE STRENGTH OF THE INVERSION AND
SATURATION BELOW IT...WILL HAVE TO WATCH FOR SOME OF THE FOG
PERSISTING PAST 15Z. GIVEN UNCERTAINTIES WITH LOW CLOUDS LATE
THIS AFTERNOON/EVENING...WILL NOT ISSUE A DENSE FOG ADVISORY AT
THIS TIME BUT ONE MAY YET BE NEEDED CENTERED AROUND 12Z SUN.
SFC-850MB RIDGE AXIS MOVES A BIT SOUTH OF THE AREA FOR SUN
AFTERNOON/NIGHT...WITH SFC-850MB WINDS MORE SOUTHWEST IN THE
5-15KT RANGE FOR MORE LOWER LEVEL MIXING. PLENTY OF DRY AIR ABOVE
THE INVERSION WITH DIURNAL WARMING/MIXING LOOKING GIVE US A SUNNY
SUNDAY AFTERNOON. MODEL SOUNDINGS INDICATING 15-20KTS ABOVE THE
NOCTURNAL INVERSION SUN NIGHT...WITH ANY RADIATIONAL VALLEY FOG
LOOKING MUCH LESS WIDESPREAD. GIVEN THE MOIST BOUNDARY LAYER FROM
RECENT RAINS...DID ADD A PATCHY FOG MENTION TO THE VALLEYS AND
MORE FOG PRONE AREAS BETWEEN 09-14Z MON. 925MB TEMPS IN THE 21C-
24C RANGE SUN AFTERNOON. WITH SOME SUNSHINE AND THE MIXING...HIGHS
SUNDAY TRENDING NEAR TO A BIT ABOVE NORMAL. USED A BLEND OF THE
GUIDANCE LOWS/HIGHS FOR TONIGHT THRU SUN NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 237 PM CDT SAT AUG 29 2015
FOR MONDAY THRU TUESDAY NIGHT...
MAIN FCST CONCERNS THIS PERIOD...ABOVE NORMAL TEMPERATURES...SMALL
SHRA/TSRA CHANCE TUE NIGHT.
29.12Z MODELS IN GOOD AGREEMENT AT THE ND SHORTWAVE LIFTS INTO
NORTHWEST ONT MON...PUSHING THE MID LEVEL RIDGE AXIS INTO MI/EASTERN
ONT. DECENT AGREEMENT THEN FOR BROAD SOUTHWEST FLOW ALOFT OVER THE
NORTH CENTRAL CONUS MON NIGHT INTO TUE NIGHT. IMPROVING CONSENSUS
FOR A SHORTWAVE TO RIPPLE NORTHEAST OUT OF THE SOUTHERN PORTION OF
THE WESTERN CONUS TROUGHING AND TOWARD/INTO THE UPPER MIDWEST TUE
NIGHT. TREND WITH THE APPROACHING SHORTWAVE TUE NIGHT IS TOWARD
STRONGER OF THE EARLIER RUNS.
PERSISTENT WESTERN TROUGHING KEEPS LEE TROUGHING OVER THE PLAINS
THRU THIS PERIOD...WITH THE REGION IN THE BROAD SOUTHWEST LOW LEVEL
FLOW AHEAD OF IT. LOWER LEVELS CONTINUE TO WARM THIS PERIOD AND WITH
A CONNECTION TO THE GULF MEX MOISTURE CONTINUES TO INCREASE AS WELL.
THIS PERIOD TO FEEL RATHER SUMMERY AS HIGHS REACH INTO THE MID 80S
TO AROUND 90 AND DEW POINTS RISE INTO THE MID/UPPER 60S. THIS
AIRMASS WILL BECOME UNSTABLE...ESPECIALLY DURING THE AFTERNOONS WITH
AS MUCH AS 1500-2500 J/KG MUCAPE. LITTLE IN THE WAY OF TRIGGERS FOR
CONVECTION SEEN OVER/CLOSE TO THE AREA MON THRU TUE AS THE ND
SHORTWAVE AND ITS ATTENDANT LOWER LEVEL TROUGH SHEAR NORTHEAST INTO
CAN. POTENTIAL FOR AS MUCH AS 100-150 J/KG CIN OVER THE AREA BOTH
MON/TUE AFTERNOONS AS WELL. WILL LEAVE MON-TUE DRY. APPROACHING
SHORTWAVE TUE NIGHT SPREADS SOME INCREASE OF LOWER LEVEL MOISTURE
TRANSPORT INTO THE AREA AND SOME REDUCTION OF THE CAPPING WITH DUE
TO WEAK 700-500MB COOLING. SMALL SHRA/TSRA CHANCE ACROSS MAINLY THE
NORTHWEST HALF OF THE FCST AREA TUE NIGHT OKAY FOR NOW. 925MB TEMPS
MON/TUE PROGGED IN THE 24C-27C RANGE...SUPPORTING HIGHS IN THE MID
80S TO NEAR 90...10F-15F ABOVE NORMAL. TRENDED TOWARD WARMER OF
GUIDANCE HIGHS MON/TUE WHILE FAVORING A BLEND OF THE GUIDANCE LOWS
MON/TUE NIGHTS.
FOR WEDNESDAY THRU SATURDAY...DAYS 4 TO 7...
MAIN FCST CONCERNS THIS PERIOD...SMALL SHRA/TSRA ALMOST ANY
PERIOD...ABOVE NORMAL TEMPERATURES.
29.00Z/2.12Z MEDIUM RANGE MODELS SHOW A GOOD CONSENSUS FOR RATHER
STRONG EASTERN NOAM RIDGING/WESTERN NOAM TROUGHING WED. IMPROVING
AGREEMENT FOR THE TUE NIGHT SHORTWAVE ENERGY TO MOVE ACROSS THE
UPPER MIDWEST WED. DECENT AGREEMENT FOR THE NOAM FLOW TO AMPLIFY
THU/FRI AS THE WEST COAST TROUGH DEEPENS AND RIDGING STRENGTHENS
OVER THE MID/UPPER MS VALLEY. TREND THU/FRI FAVORS STRONGER OF
EARLIER RUNS WITH THE WESTERN NOAM TROUGHING AND THE LESS ROBUST
WITH THE MID CONUS RIDGING. DECENT AGREEMENT FOR THE PATTERN TO
THEN SLOWLY PROGRESS SAT WITH THE WESTERN TROUGH MOVING INLAND AND
THE UPPER RIDGE AXIS SHIFTING EAST OF THE REGION. DAY 4-7
CONFIDENCE REMAINS GOOD FOR ABOVE NORMAL TEMPERATURES BUT AVERAGE
FOR THE SHRA/TSRA CHANCES.
UNDER THE RIDGING ALOFT...A WARM/MOIST LOWER LEVEL AIRMASS /PW
VALUES AND 850MB TEMPS OF 1 TO 2 STD DEVIATIONS ABOVE NORMAL/ IS
OVER THE REGION DURING THE DAY 4-7 PERIOD. SOME 1K-2K J/KG MUCAPE
PROGGED OVER THE AREA IN THIS AIRMASS DURING THE AFTERNOONS.
QUESTIONS MOST DAYS WILL BE TIMING OF THE SHORTWAVES THRU THE FLOW
AND HOW MUCH CAPPING/CIN OVER THE AREA. WITH THE SIGNAL FOR A
TRACKABLE SHORTWAVE TO MOVE ACROSS THE AREA WED...SMALL SHRA/TSRA
CHANCES THIS DAY REASONABLE FOR NOW. AREA REMAINS NEAR THE WEST/
NORTH PERIMETER OF THE MID LEVEL RIDGE THU THRU SAT...WITH MORE WEAK
AND POORLY TIMED SHORTWAVES LOOKING TO RIPPLE UP AND OVER THE WEST
SIDE OF THE RIDGING. CAPPING FURTHER UNDER THE RIDGE AXIS MAY KEEP
THE AREA PROTECTED FROM SHRA/TSRA CHANCES THU/FRI. WITH THE RIDGE
AXIS SHIFTING EAST A BIT FOR SAT...CAPPING MAY BE LESS WITH
POTENTIAL FOR A WEAK SHORTWAVE OR 2 TO SPREAD A SHRA/TSRA CHANCE
INTO THE AREA. GIVEN LESSER CONFIDENCE IN THE SMALLER SHORTWAVES AND
MESO-SCALE DETAILS IN THE WED-SAT PERIOD...WITH STAY WITH THE
MODEL/ENSEMBLE CONSENSUS SHRA/TSRA CHANCES FOR DAYS 4-7. LOWER LEVEL
TEMPERATURE PROFILES CONTINUE TO SUPPORT TEMPS AROUND 10F TO 15F
ABOVE NORMAL NEXT WEEK. MODEL/ENSEMBLE CONSENSUS HIGHS/LOWS FOR WED-
SAT GENERALLY LOOK GOOD BUT DID RAISE HIGHS IN THE MS/WI RIVER
VALLEYS A COUPLE DEGREES ABOVE THE CONSENSUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1130 PM CDT SAT AUG 29 2015
VERY CHALLENGING FORECAST.
FOG...STRATUS...OR BOTH REMAINS THE QUESTION AND LATEST MODELS RUNS
AND TRENDS AREN/T GIVING MUCH CONFIDENCE ONE WAY OR THE OTHER. THAT
SAID - THE IMPACTS ON AVIATION COULD BE THE SAME AS FLIGHT
CATEGORIES FROM FOG OR LOW STRATUS COULD BE THE SAME.
LOW STRATUS HAS BEEN RELUCTANT TO EXIT THE AREA AT LATE
EVENING...SLOWING DOWN/STOPPING. THERE ARE EVEN SOME HINTS OF
NORTHWARD DEVELOPMENT OVER NORTHERN IA. RAP MODEL SUGGEST THIS WILL
OCCUR IN EARNEST...WITH LOW CIGS SPREADING OVER SOUTHERN MN
OVERNIGHT. KLSE WOULD HOLD STEADY OR DROP A BIT IN HEIGHTS...BUT
LIKELY STAY IFR.
IF THE STRATUS DOES NOT ADVANCE INTO KRST...FOG IS THE LIKELY
OUTCOME...AND SUB 1SM IS A POSSIBILITY. SOME LOCATIONS ACROSS
SOUTHERN MN/NORTHERN IA ALREADY HAVE VSBY RESTRICTIONS. IF THE
STRATUS HOLDS AT KLSE...THE IMPACT ON VSBYS WILL NOT BE AS EXTREME AS
FIRST FORECAST.
CONFIDENCE IS HIGH IN CIGS AND/OR FOG IMPACTS AT KRST/KLSE OVERNIGHT
THROUGH MOST OF SUN MORNING. WHICH ONE IS MORE DOMINANT IS WHERE THE
CONFIDENCE IS SHAKY. GOING TO STAY THE COURSE AS A RESULT...HOLDING
WITH THE PREVIOUS FORECAST FOR THE MOST PART. EXPECT UPDATES
OVERNIGHT AS CONFIDENCE INCREASES IN THE MORE LIKELY OUTCOME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1017 AM EDT SUN AUG 30 2015
.DISCUSSION...
...HEAVY RAIN AND FLOODING THREAT CONTINUES THROUGH MONDAY...
TODAY...TROPICAL AIR MASS IN PLACE WITH GPS PRECIPITABLE WATER
VALUES AT LEAST 2.2 TO 2.3 INCHES. THE 12Z SURFACE ANALYSIS SHOWED
AN INVERTED TROUGH (REMNANTS OF ERIKA) EXTENDING FROM THE LOWER KEYS
TO SOUTH FLORIDA. THIS LOW LEVEL TROUGH LIKELY EXTENDED EVEN FARTHER
NORTHWARD TO NEAR CAPE CANAVERAL SINCE THE BUOYS OFFSHORE WERE
SHOWING BREEZY SOUTHEAST FLOW WHILE OUR NORTHERN LAND AREAS WERE
LIGHT IN THE EARLY MORNING HOURS.
NORTHERN BAHAMA CONVERGENCE LINES AND COASTAL CONVERGENCE HAVE LED
TO A FEW ROUNDS OF SHOWERS/STORMS ALONG THE COAST THIS MORNING.
EXPECT THIS WILL CONTINUE INTO THE AFTERNOON AS SATELLITE WAS
SHOWING A LARGER SCALE OUTFLOW BOUNDARY APPROACHING GRAND BAHAMA
FROM THE SOUTH...WHICH WILL LIKELY GENERATE SOME LARGER CLUSTERS OF
STORMS.
THE INTERIOR HAS BEEN BRUSHED BY A FEW SHOWERS THIS MORNING AND
THERE WERE LIKELY SOME OUTFLOW BOUNDARIES PRESSING INLAND FROM THE
COASTAL CONVECTION. EXPECT WITH THE HIGH MOISTURE IN PLACE AND
MODEST HEATING THROUGH LATE MORNING THERE WILL BE A RATHER LARGE
CLUSTER OF STORMS DEVELOPING. THE HRRR MODEL HAS BEEN SHOWING THIS
BLOWUP LIFTING NORTHWARD UP THE INTERIOR WITH SOME AFFECTING THE
COASTAL COUNTIES TOO.
THIS SETUP ALONG WITH SOME DIVERGENCE ALOFT WILL LEAD TO A HIGH
COVERAGE OF RAINFALL ACROSS THE ENTIRE AREA. LOCATIONS THAT RECEIVE
SEVERAL ROUNDS OF SHOWERS/STORMS COULD HAVE RAINFALL TOTALS 2-3
INCHES...SO FLOOD WATCH IN PLACE LOOKS GOOD.
WE COULD JUST ABOUT RING THE BELL TODAY AND GO WITH 100 PERCENT
POPS. DO NOT PLAN ANY SIGNIFICANT CHANGES TO THE PREVIOUS FORECAST
PACKAGE THOUGH...WHICH SHOWS ANOMALOUSLY HIGH 90 POPS. WITH ALL THE
RAIN AND CLOUDS...TEMPS WILL HAVE TROUBLE REACHING THE UPPER 80S AND
MIGHT HAVE TO TWEAK READINGS DOWN A FEW DEGREES HERE AND THERE.
&&
.AVIATION...NO CHANGES TO PREVIOUS DISCUSSION
HIGH COVERAGE OF SHOWERS AND STORMS EXPECTED ACROSS THE REGION TODAY
WITH A VERY MOIST TROPICAL AIRMASS IN PLACE. GREATEST COVERAGE AND
BEST CHANCE FOR REDUCTIONS TO IFR/MVFR CONDS WILL BE ALONG THE COAST
IN THE MORNING...THEN EXPECT WIDESPREAD SHOWER/SCT STORM COVERAGE
ACROSS THE ENTIRE AREA INTO THE AFT. RAIN CHANCES DECREASE ACROSS
THE INTERIOR PAST MIDNIGHT WITH SHOWERS AND STORMS REMAINING LIKELY
ALONG THE COAST.
&&
.MARINE...
TODAY/TONIGHT...POOR TO HAZARDOUS BOATING CONDITIONS WILL OCCUR AS
REMNANT LOW PRESSURE TROUGH FROM ERIKA...NEAR SOUTH FL...PRODUCES
GUSTY SOUTHEAST WINDS. WIND SPEEDS 15 TO 20 KNOTS WILL BUILD SEAS UP
TO 6-7 FEET OFFSHORE. IN ADDITION WIDESPREAD SHOWERS AND SCATTERED
STORMS WITH GUSTY WINDS WILL CONTINUE TO DEVELOP AND MOVE NORTH TO
NORTHWEST OVER THE WATERS.
THOUGH THE STORMY WEATHER CONDITIONS SHOULD KEEP MOST SMALL CRAFT IN
PORT...THERE IS A SMALL CRAFT ADVISORY IN EFFECT FOR THE TREASURE
COAST WATERS AND OFFSHORE BREVARD COUNTY...WITH EXERCISE CAUTION
STATEMENTS ELSEWHERE.
&&
.HYDROLOGY...NO CHANGE TO THE PREVIOUS DISCUSSION
RAINFALL TOTALS AROUND TO 2 TO 4 INCHES ARE FORECAST ACROSS EAST
CENTRAL FLORIDA THROUGH MONDAY NIGHT WITH LOCALLY HIGHER AMOUNTS UP
TO 5 TO 6 INCHES POSSIBLE. MAIN CONCERNS FOR ANY FLOODING WILL BE
ALONG THE COAST FROM BREVARD SOUTHWARD WHERE ANY PERSISTENT RAIN
BANDS CAN DEVELOP. ALSO...SHINGLE CREEK AT CAMPBELL (SHIF1) IS ONLY
ABOUT 0.2 FEET BELOW ACTION STAGE. ANY ADDITIONAL HEAVY RAINFALL
TOTALS ACROSS THE SHINGLE CREEK BASIN TODAY MAY PRODUCE MINOR
FLOODING AT THIS SITE AND WILL HAVE TO BE MONITORED CLOSELY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH MONDAY EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-INLAND VOLUSIA COUNTY-MARTIN-NORTHERN BREVARD
COUNTY-NORTHERN LAKE COUNTY-OKEECHOBEE-ORANGE-OSCEOLA-
SEMINOLE-SOUTHERN BREVARD COUNTY-SOUTHERN LAKE COUNTY-ST.
LUCIE.
AM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR SEBASTIAN
INLET TO JUPITER INLET 0-20 NM-SEBASTIAN INLET TO JUPITER
INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN
INLET 20-60 NM.
&&
$$
FORECASTS...LASCODY
IMPACT WX....SEDLOCK/VOLKMER
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
744 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A STRONG UPPER LEVEL DISTURBANCE WILL LIFT NORTH THROUGH GEORGIA
AND THE CAROLINAS THROUGH TONIGHT. ON THE PERIPHERY OF ATLANTIC HIGH
PRESSURE...A WEAK TROUGH OF LOW PRESSURE WILL MEANDER OVER THE
SOUTHEAST MOST OF THIS WEEK. LATE THIS WEEK INTO NEXT WEEKEND...LOW
PRESSURE WILL DEVELOP OVER THE ATLANTIC WHILE WEAK INLAND HIGH
PRESSURE EXPANDS SOUTH AND EAST INTO THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH TONIGHT...AN ANOMALOUS MID AND UPPER LOW OVER THE WESTERN
FLORIDA PANHANDLE AT DAYBREAK WILL LIFT NE AND GRADUALLY OPEN INTO
A WAVE AS IT HEADS TOWARD THE SOUTHERN APPALACHIANS. THIS FEATURE
WILL RESULT IN AN STEADY INFLUX OF DEEP MOISTURE WITH PWATS ABOVE
2 INCHES INTO SOUTHERN SC AND SE GA. IT ALSO ARRIVES WITH DECENT
FORCING FOR ASCENT IN RESPONSE TO A 40-45 JET MAX AT 500 MB AND
STEADY UPPER DIVERGENCE AS IT PASSES OVERHEAD. THIS WILL CAUSE AT
LEAST SCATTERED TO NUMEROUS COVERAGE OF RAINFALL WITH POCKETS OF
DEEP CONVECTION LIKELY ALONG WITH OCCASIONAL DOWNPOURS.
A COMPLEX MESOSCALE WITH UNSEASONABLY STRONG LOW LEVEL MOISTURE
GRADIENTS LAST NIGHT HAS GIVEN WAY TO RAINS MARCHING NORTH WITH SOME
THUNDER ALONG COASTAL AND SOUTHERN ZONES. THERE SHOULD BE A GOOD
POTENTIAL FOR LOCALLY HEAVY RAINFALL TODAY...THE GFS AND RECENTLY
HIGH RESOLUTION OUTPUTS FROM BOTH THE HRRR AND NSSL ARW MODELS
SUGGEST THERE COULD ALSO BE A LULL IN HEAVY RAIN POTENTIAL NORTH
OF THE SAVANNAH RIVER THIS AFTERNOON BETWEEN TSTMS DEVELOPING
AHEAD OF THE EJECTING LOW ACROSS EAST CENTRAL GEORGIA/CSRA AND
COASTAL CONVERGENCE CONTINUING TO THE SOUTH OF THE SAVANNAH
RIVER. MODELS SUGGEST STEEPENING INLAND LAPSE RATES ALONG WITH AT
LEAST 25 KT OF 0-6 KM BULK SHEAR ACROSS OUR INLAND ZONES THIS
AFTERNOON AND EVENING. INLAND AREAS TO WEST OF I-95 COULD SEE A
WINDOW FOR ISOLATED STRONG TO SEVERE TSTMS AS UPPER LEVEL FORCING
INCREASES AHEAD OF VERY WELL DEFINED DRIER SLOT BETWEEN 850 MB AND
500 MB. WOULD NOT BE SURPRISED TO SEE CONVECTION ORGANIZE LATER
TODAY TO THE WEST OF I-95 AND WE WILL HAVE TO MONITOR FOR ISOLATED
SEVERE WEATHER POTENTIAL...ESPECIALLY ALONG TO THE W OF I-95.
TONIGHT...CONTINUED COMPLEXITIES AS THE UPPER LOW EJECTS BY AND
DRYING MID LEVELS EVENTUALLY SHUT DOWN RAINS ALONG AND WEST OF
I-95 BUT ATTENTION TURNS TO HEAVY RAIN POTENTIAL ALONG COASTAL
SOUTH CAROLINA AFTER MIDNIGHT AS STRONG UPPER DIVERGENCE WILL
ENHANCE LIFT WHILE DEEP LAYERED MOISTURE AND SIGNIFICANT LOW LEVEL
MOISTURE CONVERGENCE ENHANCES CONVECTIVE RAINS. WE RAMP POPS UP
TO CATEGORICAL ALONG THE CENTRAL SOUTH CAROLINA COAST LATE.
LOCALLY HEAVY RAINS...PERHAPS ISOLATED EXCESSIVE RAINFALL MAY
OCCUR ALONG CHARLESTON COUNTY IF THE LATEST MODEL GUIDANCE PANS
OUT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MONDAY MORNING...THE UPPER TROUGH AND ASSOCIATED FORCING FOR ASCENT
WILL HAVE ADVANCED NORTH/NORTHEAST OF THE REGION. HOWEVER...FOCUSED
LOW/MID LEVEL MOISTURE TRANSPORT AND AN ASSOCIATED PLUME OF PWATS 2
TO 2.25 INCHES WILL CONTINUE TO PUSH ONSHORE ESPECIALLY INTO SOUTH
CAROLINA COUNTIES. GIVEN ABOVE-AVERAGE MODEL AGREEMENT REGARDING
THIS SCENARIO...MONDAY MORNING FEATURES LIKELY/CATEGORICAL POPS
ALONG/EAST OF I-95...HIGHEST INTO SC COUNTIES INCLUDING THE
CHARLESTON TRI-COUNTY REGION. GIVEN ELEVATED PWATS AND HIGH
PRECIPITATION EFFICIENCY...INTRODUCED A MENTION OF HEAVY RAIN INTO
AREAS ALONG/EAST OF I-95. ALSO...AN ELEVATED HIGH TIDE WILL OCCUR
BETWEEN 900 AND 1100 AM...AND IF/WHERE HEAVY RAIN IS FALLING WITHIN
COASTAL COUNTIES LOCALIZED FLOODING WILL BE POSSIBLE. THIS POTENTIAL
INCLUDED DOWNTOWN CHARLESTON.
MONDAY AFTERNOON...POPS BECOME LESS WELL DEFINED DUE TO THE UNKNOWN
IMPACT OF MORNING SHOWERS/THUNDERSTORMS AND DUE TO THE POTENTIAL FOR
SUBTLE DRYING TO OCCUR ACROSS NORTHERN/INLAND COUNTIES. EARLY
AFTERNOON POPS ARE TAPERED FROM LIKELY NEAR THE COAST TO CHANCE
INLAND.
OTHERWISE...DUE TO CLOUDS AND PRECIPITATION...MONDAY HIGH TEMPS IN
THE LOWER/MID 80S SHOULD BE COMMON...SLIGHTLY BELOW NORMAL FOR LATE
AUGUST.
MONDAY NIGHT...A POOL OF DEEP MOISTURE WILL REMAIN FOCUSED NEAR THE
COAST AND OVER COASTAL WATERS. INLAND POPS DECREASE FROM CHANCE TO
SLIGHT CHANCE WITH TIME INLAND...WHILE POPS NEAR THE COAST REMAIN IN
THE 50-60 PERCENT RANGE...HIGHEST OVER CENTRAL/SOUTHERN COASTAL
COUNTIES. LOCALLY EXCESSIVE RAINFALL WILL REMAIN POSSIBLE NEAR THE
COAST.
THE SCENARIO APPEARS SIMILAR TUESDAY THROUGH WEDNESDAY. WHILE
SLIGHTLY DRIER AIR COULD INFILTRATE NORTHERN/INLAND COUNTIES...A
POOL OF ENHANCED MOISTURE WILL REMAIN TRAPPED BENEATH A BUILDING
UPPER RIDGE...ESPECIALLY OVER SOUTHERN COUNTIES AND ACROSS ADJACENT
COASTAL WATERS. POPS ARE DISTRIBUTED ACCORDINGLY...WITH
HIGHEST/LIKELY POPS ACROSS SOUTHERN COUNTIES. HIGH PWATS AND WEAK
STEERING FLOW WILL CONTINUE TO SUPPORT THE POTENTIAL FOR LOCALLY
HEAVY RAINFALL. TEMPS WILL DEPEND ON CLOUD/PRECIPITATION COVERAGE.
HIGHS IN THE MID 80S WILL REMAIN COMMON BOTH DAYS. HOWEVER...
TEMPERATURES COULD REMAIN IN THE LOWER 80S IF/WHERE CLOUDS/SHOWERS
PERSIST...WHILE TEMPERATURES COULD RECOVER INTO THE UPPER 80S WHERE
PRECIPITATION COVERAGE IS REDUCED...ESPECIALLY INLAND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
UNTIL LATE WEEK...SUFFICIENT MOISTURE WILL PERSIST BENEATH AN UPPER
RIDGE TO SUPPORT AT LEAST SCATTERED SHOWERS/THUNDERSTORMS ESPECIALLY
DURING THE MIDDAY/EVENING HOURS AND ALONG THE COAST/OVER ADJACENT
COASTAL WATERS DURING THE LATE NIGHT/EARLY MORNING HOURS. LATE THIS
WEEK INTO NEXT WEEKEND OFF THE MID ATLANTIC COAST NEAR 37N/70W...AN
AMPLIFYING UPPER TROUGH WILL PROMOTE SURFACE CYCLOGENESIS...AND THIS
SYSTEM WILL EVOLVE INTO DEEP LAYERED/CUT-OFF LOW PRESSURE. THIS
SYSTEM WILL DRIVE THE UPPER RIDGE WELL SOUTH OF THE REGION...BUT THE
IMPACTS ON SENSIBLE WEATHER REMAIN UNCERTAIN. IF THE ATLANTIC TROUGH
PHASES WITH THE UPPER LOW ALONG THE GULF COAST...AN UNSETTLED
PATTERN COULD DEVELOP OVER THE REGION. HOWEVER...IF THE SYSTEMS
REMAIN SEPARATE...SOMEWHAT DRIER AIR COULD SPREAD INTO THE REGION
FROM THE NORTH/NORTHWEST. THUS...POPS REMAIN PRETTY CLOSE TO
NORMAL. TEMPERATURES SHOULD REMAIN CLOSE TO NORMAL THROUGH THE
PERIOD...AND FORECAST TEMPERATURES REMAIN BELOW 90F THROUGH NEXT
WEEKEND. HOWEVER...THE PROBABILITY FOR WARMER TEMPS INTO THE LOWER
90S COULD INCREASE LATE WEEK INTO NEXT WEEKEND ESPECIALLY IF DRIER
AIR CIRCULATES INTO THE REGION.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THE OVERALL PICTURE REMAINS VERY UNSETTLED THROUGH TONIGHT WITH
THE SYNOPTIC PATTERN FAVORING PERIODIC SHOWERS WITH A CHANCE
OF TSTMS. GUIDANCE HINTS THAT MORE ACTIVE PERIODS OF CONVECTION
THIS AFTERNOON MAY LOWER CIGS AND VSBYS INTO MVFR RANGE WITH
POCKETS OF IFR VSBYS POSSIBLE UNDER THE HEAVIER CONVECTIVE
ELEMENTS WHERE DOWNPOURS ARE OCCURRING.
TONIGHT...RAINS ARE EXPECTED TO DIMINISH OVERNIGHT AT KSAV BUT
INCREASE AT KCHS AFTER 08Z AS DEEP MOISTURE PILES INTO THE
SOUTH CAROLINA COAST...ENHANCED BY GOOD LOW LEVEL SPEED
CONVERGENCE AND A RIBBON OF UPPER LEVEL FORCING FOR ASCENT.
EXTENDED AVIATION OUTLOOK THROUGH THURSDAY...PERIODS OF FLIGHT
RESTRICTIONS APPEAR LIKELY THROUGH EARLY WEEK...ESPECIALLY IN
SHOWERS/THUNDERSTORMS. VFR SHOULD BECOME MORE COMMON MID TO LATE
WEEK.
&&
.MARINE...
ONSHORE FLOW WILL INCREASE ACROSS GEORGIA WATERS LATER TODAY AND
TONIGHT...PERHAPS 15-20 KT WITH SOME HIGHER GUSTS POSSIBLE FROM
GRAYS REEF AND BEYOND. THIS COULD ASSIST SEAS BUILDING TO SMALL
CRAFT ADVISORY LEVELS OVER GEORGIA WATERS FROM 20-60 NM LATER
TONIGHT. WIDESPREAD RAINS AND OCCASIONAL TSTMS OVER THE WATERS
THROUGH TONIGHT WILL LOWER VSBYS BELOW 3 NM AT TIMES AND PRODUCE
LOCALLY GUSTY WINDS...ESPECIALLY TONIGHT. WE HAVE HELD OFF ON
ISSUING AN SCA FOR OUTER WATERS JUST YET UNTIL WE GET A BETTER
HANDLE ON CONVECTION PATTERNS WHICH MAY DISRUPT WINDS BUT
LOCALLY ENHANCE WAVES.
PERSISTENT SE WINDS COULD USHER A 6 FT SWELL INTO GA COASTAL WATERS
BEYOND 20-40 NM MONDAY. THIS SCENARIO REMAINS UNCERTAIN...THUS WILL
NOT YET RAISE A SMALL CRAFT ADVISORY. OTHERWISE...SOUTHEAST WINDS
SHOULD REMAIN CAPPED AT 15-20 KT AND SEAS SHOULD REMAIN 3-5 FT
THROUGH TUESDAY. MID TO LATE WEEK...A WEAKENING ONSHORE PRESSURE
GRADIENT WILL TRANSLATE TO LIGHTER WINDS...FREQUENTLY 10 KT OR
LESS...AND SEAS SHOULD SUBSIDE TO 1-3 FT...HIGHEST BEYOND 20 NM.
MEANWHILE...SHOWERS/THUNDERSTORMS WILL REMAIN COMMON OVER COASTAL
WATERS THROUGH THIS WEEK. STRONGER THUNDERSTORMS COULD PRODUCE GUSTY
WINDS...FREQUENT LIGHTNING AND POOR VISIBILITY IN VERY HEAVY
RAINFALL. MARINERS SHOULD REMAIN ALERT FOR SPECIAL MARINE WARNINGS
AND MARINE WEATHER STATEMENTS.
MARINERS ARE ADVISED THAT SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS WILL OCCUR EACH OF THE NEXT SEVERAL DAYS AND NIGHTS.
SOME OF THESE STORMS WILL PRODUCE FREQUENT LIGHTNING...HEAVY RAINS
REDUCING VISIBILITIES TO NEAR ZERO AT TIMES AND WIND GUSTS UP TO
AT LEAST 30 KT WITH BRIEFLY HIGHER SEAS. REMEMBER TO MONITOR OUR
FORECASTS AND YOUR NOAA WEATHER RADIO.
CONDITIONS WON/T BE MUCH DIFFERENT SUNDAY WITH ONSHORE
WINDS...SMALL SWELLS AND ASTRONOMICAL INFLUENCES FROM THE PERIGEE
AND FULL MOON. THIS WILL RESULT IN AT LEAST A MODERATE RISK OF RIP
CURRENTS AT AREA BEACHES.
WHILE WE START TO LOSE THE ASTRONOMICAL INFLUENCES AS WE GO THROUGH
THE WEEK...THERE IS STILL AN ONSHORE WIND COMPONENT AND POSSIBLE
SMALL SWELLS TO GENERATE A POSSIBLE ELEVATED RISK DURING AT LEAST THE
EARLY PART OF THE WEEK.
RIP CURRENTS...A HIGH RISK OF RIP CURRENTS AT TYBEE ISLAND TODAY
GIVEN SWELL PERIODS WERE NOW OVER 10 SECONDS WITH OTHERWISE
FAVORABLE CONDITIONS INCLUDING PERSISTENCE FROM SATURDAY. SOUTH
CAROLINA COAST WILL HAVE A MODERATE RISK THROUGH THIS EVENING...
OTHERWISE AN ELEVATED RISK FOR RIP CURRENTS COULD PERSIST INTO
EARLY THIS WEEK.
&&
.TIDES/COASTAL FLOODING...
THROUGH TONIGHT...ASTRONOMICAL INFLUENCES DUE TO THE PERIGEAN
SPRING TIDE PLUS ONSHORE WINDS WILL MAINTAIN ELEVATED HIGH TIDE
LEVELS ALONG THE COAST. WHILE WE WILL BE CLOSE TO POSSIBLE
SHALLOW COASTAL FLOODING IN CHARLESTON HARBOR WITH THE MORNING
HIGH TIDE TODAY...A BETTER CHANCE FOR SHALLOW SALT WATER FLOODING
EXISTS WITH THE EVENING HIGH TIDE. COASTAL FLOOD ADVISORIES WILL
LIKELY BE REQUIRED FOR AT LEAST PARTS OF THE SC COAST...AND WE/LL
BE CLOSE TO THE ADVISORY CRITERIA FURTHER SOUTH...INCLUDING THE
SAVANNAH AREA. ALSO OF NOTE...PERIODS OF SHOWERS/THUNDERSTORMS
WITH HEAVY RAIN ARE EXPECTED. IF HEAVY RAIN FALLS IN COASTAL
COMMUNITIES...INCLUDING DOWNTOWN CHARLESTON AND/OR DOWNTOWN
SAVANNAH AROUND THE TIMES OF HIGH TIDE...MORE SIGNIFICANT FLOODING
IS POSSIBLE.
MONDAY AND TUESDAY...LINGERING ASTRONOMICAL INFLUENCES AND
PERSISTENT ONSHORE FLOW COULD PRODUCE A COUPLE OF ADDITIONAL CYCLES
OF SHALLOW SALT WATER FLOODING WITH THE NIGHTTIME HIGH
TIDE...ESPECIALLY ALONG THE SOUTH CAROLINA COAST. ALSO OF CONCERN...
PERIODS OF HEAVY RAIN ARE POSSIBLE ALONG THE COAST EARLY THIS
WEEK...AND LOCALIZED FLOODING IS POSSIBLE ESPECIALLY IF HEAVY RAIN
FALLS AROUND THE TIMES OF HIGH TIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...HIGH RISK FOR RIP CURRENTS THROUGH THIS EVENING FOR GAZ117-119-
139-141.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...SPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1055 AM CDT SUN AUG 30 2015
.UPDATE...
ISSUED AT 1050 AM CDT SUN AUG 30 2015
FOG FINALLY STARTING TO LIFT AND BREAK UP NW OF THE STALLED
FRONTAL BOUNDARY DRAPED ACROSS CENTRAL ILLINOIS THIS MORNING.
SOUTHERLY WINDS SOUTH OF THE BOUNDARY WILL RESULT IN SOME DRIFT
NORTHWARD..WITH PLENTY OF LLVL MOISTURE IN PLACE TO FILL IN THE
SKY WITH A BKN CU FIELD SHORTLY AFTER ANY CLEARING TAKES PLACE
THIS AFTERNOON. SAME CU COULD DEVELOP SOME VERTICAL EXTENT AND
TURN INTO SCT SHOWERS AND THUNDERSTORMS, PARTICULARLY SOUTH AND
EAST OF THE BOUNDARY. NO UPDATES ANTICIPATED AT THIS TIME, JUST
MINOR ADJUSTMENTS TO HOURLY TEMP TRENDS UNDER THE STRATUS/REMAINING
FOG IN THE NW.
&&
.SHORT TERM...(TODAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
08Z/3AM SURFACE ANALYSIS SHOWS A STATIONARY FRONTAL BOUNDARY
EXTENDING FROM JUST SOUTH OF CHICAGO TO NEAR KIRKSVILLE, MISSOURI.
WHILE CURRENT KILX RADAR IMAGERY INDICATES DRY CONDITIONS ACROSS THE
BOARD...A FEW SHOWERS ARE NOTED FURTHER SOUTHWEST FROM THE OZARKS
INTO THE OHIO RIVER VALLEY. MEANWHILE...LIGHT/VARIABLE WINDS AND
INCREASED LOW-LEVEL MOISTURE NEAR THE BOUNDARY HAVE LED TO THE
DEVELOPMENT OF FOG MAINLY ALONG/NORTHWEST OF A PITTSFIELD TO
BLOOMINGTON-NORMAL LINE. HRRR CONTINUES TO FOCUS MUCH OF THE
WIDESPREAD FOG ACROSS THIS AREA THROUGH MID-MORNING...SO WILL NEED
TO MONITOR VISBY TRENDS FOR A POSSIBLE DENSE FOG ADVISORY. FURTHER
EAST AND SOUTH ACROSS THE REMAINDER OF THE CWA...WILL ONLY MENTION
PATCHY FOG EARLY THIS MORNING. AFTER THE MORNING FOG
DISSIPATES...WIDELY SCATTERED SHOWERS/THUNDER WILL DEVELOP AHEAD OF
THE DECAYING FRONTAL BOUNDARY...PRIMARILY EAST OF THE ILLINOIS
RIVER. AFTERNOON HIGH TEMPERATURES WILL BE SIMILAR TO
YESTERDAY...PERHAPS A DEGREE OR TWO WARMER IN THE MIDDLE 80S.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
THE EXTENDED LOOKS WARM AND DRY AS UPPER-LEVEL RIDGING DOMINATES THE
EASTERN CONUS THROUGH THE END OF THE WEEK. A SLIGHT WEAKNESS IN THE
RIDGE APPEARS TO DEVELOP ACROSS ILLINOIS INTO THE OHIO RIVER
VALLEY...POTENTIALLY TRIGGERING ISOLATED AFTERNOON/EVENING
CONVECTION TUESDAY THROUGH FRIDAY. HOWEVER...MID-LEVEL WARMING
BENEATH THE RIDGE WILL LIKELY LEAD TO CAPPING AND AN OVERALL
SUPPRESSION OF CONVECTION. AS A RESULT...WILL MAINTAIN A DRY
FORECAST WITH HIGH TEMPERATURES CLIMBING INTO THE UPPER 80S AND
LOWER 90S EACH DAY. THE NEXT SIGNIFICANT CHANCE FOR PRECIPITATION
WILL LIKELY HOLD OFF UNTIL EARLY NEXT WEEK WHEN A SHORT-WAVE TROUGH
GRADUALLY FLATTENS THE PREVAILING RIDGE AND PUSHES A COLD FRONT INTO
THE REGION. MODELS ARE NOT IN AGREEMENT CONCERNING TIMING THIS FAR
OUT...BUT TYPICAL TREND IN THIS TYPE OF SCENARIO IS USUALLY SLOWER.
AS A RESULT...WILL MAINTAIN DRY WEATHER THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CDT SUN AUG 30 2015
PATCHY DENSE FOG POSSIBLE TO START THE DAY ACROSS THE CENTRAL
ILLINOIS TERMINAL AREA. THE FOG SHOULD BE BURNING OFF OVER THE
NEXT COUPLE OF HOURS, LEAVING VFR CONDITIONS FOR THE BULK OF THE
12Z TAF VALID TIME. HOWEVER, FOG MAY REDEVELOP LATER TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
653 AM CDT SUN AUG 30 2015
.SHORT TERM...(TODAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
08Z/3AM SURFACE ANALYSIS SHOWS A STATIONARY FRONTAL BOUNDARY
EXTENDING FROM JUST SOUTH OF CHICAGO TO NEAR KIRKSVILLE, MISSOURI.
WHILE CURRENT KILX RADAR IMAGERY INDICATES DRY CONDITIONS ACROSS THE
BOARD...A FEW SHOWERS ARE NOTED FURTHER SOUTHWEST FROM THE OZARKS
INTO THE OHIO RIVER VALLEY. MEANWHILE...LIGHT/VARIABLE WINDS AND
INCREASED LOW-LEVEL MOISTURE NEAR THE BOUNDARY HAVE LED TO THE
DEVELOPMENT OF FOG MAINLY ALONG/NORTHWEST OF A PITTSFIELD TO
BLOOMINGTON-NORMAL LINE. HRRR CONTINUES TO FOCUS MUCH OF THE
WIDESPREAD FOG ACROSS THIS AREA THROUGH MID-MORNING...SO WILL NEED
TO MONITOR VISBY TRENDS FOR A POSSIBLE DENSE FOG ADVISORY. FURTHER
EAST AND SOUTH ACROSS THE REMAINDER OF THE CWA...WILL ONLY MENTION
PATCHY FOG EARLY THIS MORNING. AFTER THE MORNING FOG
DISSIPATES...WIDELY SCATTERED SHOWERS/THUNDER WILL DEVELOP AHEAD OF
THE DECAYING FRONTAL BOUNDARY...PRIMARILY EAST OF THE ILLINOIS
RIVER. AFTERNOON HIGH TEMPERATURES WILL BE SIMILAR TO
YESTERDAY...PERHAPS A DEGREE OR TWO WARMER IN THE MIDDLE 80S.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
THE EXTENDED LOOKS WARM AND DRY AS UPPER-LEVEL RIDGING DOMINATES THE
EASTERN CONUS THROUGH THE END OF THE WEEK. A SLIGHT WEAKNESS IN THE
RIDGE APPEARS TO DEVELOP ACROSS ILLINOIS INTO THE OHIO RIVER
VALLEY...POTENTIALLY TRIGGERING ISOLATED AFTERNOON/EVENING
CONVECTION TUESDAY THROUGH FRIDAY. HOWEVER...MID-LEVEL WARMING
BENEATH THE RIDGE WILL LIKELY LEAD TO CAPPING AND AN OVERALL
SUPPRESSION OF CONVECTION. AS A RESULT...WILL MAINTAIN A DRY
FORECAST WITH HIGH TEMPERATURES CLIMBING INTO THE UPPER 80S AND
LOWER 90S EACH DAY. THE NEXT SIGNIFICANT CHANCE FOR PRECIPITATION
WILL LIKELY HOLD OFF UNTIL EARLY NEXT WEEK WHEN A SHORT-WAVE TROUGH
GRADUALLY FLATTENS THE PREVAILING RIDGE AND PUSHES A COLD FRONT INTO
THE REGION. MODELS ARE NOT IN AGREEMENT CONCERNING TIMING THIS FAR
OUT...BUT TYPICAL TREND IN THIS TYPE OF SCENARIO IS USUALLY SLOWER.
AS A RESULT...WILL MAINTAIN DRY WEATHER THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CDT SUN AUG 30 2015
PATCHY DENSE FOG POSSIBLE TO START THE DAY ACROSS THE CENTRAL
ILLINOIS TERMINAL AREA. THE FOG SHOULD BE BURNING OFF OVER THE
NEXT COUPLE OF HOURS, LEAVING VFR CONDITIONS FOR THE BULK OF THE
12Z TAF VALID TIME. HOWEVER, FOG MAY REDEVELOP LATER TONIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS CARIBOU ME
620 AM EDT SUN AUG 30 2015
.SYNOPSIS...
A WEAK COLD FRONTAL BOUNDARY FROM QUEBEC WILL CROSS THE REGION
TODAY. ANOTHER COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION BY
MONDAY AFTERNOON...FOLLOWED BY DRIER AND COOLER AIR WITH CANADIAN
HIGH PRESSURE MONDAY NIGHT AND TUESDAY. WEST SOUTHWEST WINDS ON
WEDNESDAY AS THE HIGH MOVES EAST OF THE REGION WILL BRING MUCH
WARMER CONDITIONS ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
615 AM UPDATE...THE BULK OF THE SHOWER ACTIVITY HAS EXITED INTO
NEW BRUNSWICK THIS MORNING. MEANWHILE, A WEAK FRONTAL BOUNDARY
REMAINS DRAPED JUST TO OUR NORTH. THIS BOUNDARY WILL SLIDE SOUTH
THROUGH THE DAY TODAY. THE LATEST HRRR CONTINUES TO TRY TO SHOW
ADDITIONAL PRECIPITATION DEVELOPING LATER THIS MORNING INTO THE
EARLY AFTERNOON ALONG THIS BOUNDARY, BUT STILL BELIEVE THE MODEL
IS OVERDONE. HOWEVER, HAVE KEPT ISOLATED SHOWERS IN FOR NORTHERN
AND EASTERN MAINE THROUGH THE MORNING HOURS TO ACCOUNT FOR THE
SLIGHT CHANCE OF A SPRINKLE OR TWO. OVERALL CHANGES TO THE
FORECAST WERE MINOR WITH THIS UPDATE.
PREVIOUS DISCUSSION...UPPER SHORTWAVE IS RAPIDLY SLIDING ACROSS
SOUTHERN QUEBEC EARLY THIS MORNING. ISOLATED TO SCATTERED SHOWERS
ASSOCIATED WITH THIS FEATURE ARE CURRENTLY PUSHING ACROSS NORTHERN
AND CENTRAL PORTIONS OF OUR FORECAST AREA. THIS PRECIPITATION IS
ALSO MOVING FAIRLY QUICKLY; THE BULK OF THE ACTIVITY IS SLATED TO
MOVE INTO NEW BRUNSWICK BY MID MORNING. THIS IS SUPPORTED BY THE
LATEST HRRR GUIDANCE, WHICH HAS ALL BUT ONE OR TWO SHOWERS EXITING
OUR AREA AROUND 14Z/10 AM. IT IS NOTED THAT THE HRRR ALSO TRIES TO
PRODUCE SOME POP-UP SHOWERS ACROSS THE NORTH THIS AFTERNOON, BUT
WITH DRIER AIR WORKING IN BEHIND THE UPPER WAVE, CURRENT THINKING
IS THAT ALL WE`LL SEE IS SOME CUMULUS CLOUDS WITH PERHAPS SOME
VIRGA. BRIEF RIDGING BUILDS IN FOR LATER THIS AFTERNOON INTO
TONIGHT. HOWEVER, ANOTHER STRONGER UPPER TROUGH AND SURFACE COLD
FRONT WILL APPROACH LATE TONIGHT, WITH SHOWERS MOVING INTO
NORTHERN AREAS AFTER MIDNIGHT. HIGHS TODAY WILL BE IN THE MID 70S
TO AROUND 80 WHILE OVERNIGHT LOWS WILL BE IN THE UPPER 50S TO
LOWER 60S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE L/WV PATTERN OVR NA INTO THE LATE WEEK WILL FEATURE A
BUILDING MDTLY HI AMPLITUDE RIDGE OVR THE ERN GREAT LKS AS AN
UPPER TROF BUILDS SWRD OVR THE W COAST. THIS PLACES NRN/ERN ME IN
THE NE QUADRANT OF THIS RIDGE... MEANING THAT ALTHOUGH TEMPS WILL
LIKELY AVG ABV NORMAL FOR THIS PD...THE REGION WILL BE SUBJECT TO
COLD FRONTAL PASSAGES AS S/WVS CRESTING THE RIDGE IN CNTRL CAN N
OF THE GREAT LKS DROP ESEWRD INTO CAN MARITIMES.
THE FIRST OF THESE S/WVS WILL BE CROSSING JUST N OF THE FA ON MON
BRINGING CLDNSS AND SHWRS TO MSLY NRN PTNS OF THE FA LATE MON MON
THRU MIDDAY AND PERHAPS INTO CNTRL PTNS OF THE FA ERLY TO MID
AFTN. ATTM...WARM MID LVL TEMPS WILL LIKELY KEEP SHWRS FROM
DEVELOPING INTO TSTMS OVR ME...BUT AN ISOLD TSTM CANNOT BE
COMPLETELY RULED OUT TUE AFTN ALG THE NE ME/NW NB BORDER BEFORE
THE S/WV MOVES E OF THE FA LATE MON AFTN. RNFL AMOUNTS ARE LIKELY
TO BE GREATEST IN THE ST JOHN VLY WHERE UP TO A TENTH OF AN INCH
IS POSSIBLE...WITH LESSER OR NO RN AS ONE TRAVERSES FURTHER S.
BEHIND THE FRONT...COOLER AND MUCH DRIER AIR FROM N CNTRL CAN WILL
ADVECT SWRD INTO THE FA MON NGT INTO TUE...WITH DWPTS DROPPING
INTO THE 40S ACROSS NRN AND CNTRL PTNS OF THE FA BY TUE MORN.
TEMPS WILL INITIALLY BE SLOW TO RISE MON MORN WITH MDT LLVL COLD
ADVCN...THEN MAKE MAKE A LITTLE FASTER RECOVERY TO NEAR SEASONAL
NORMS TUE AFTN AS THE LLVL TEMP ADVCN BECOMES MORE NEUTRAL ALL
UNDER SUNNY SKIES. A DRY WARM FRONT WILL CROSS THE REGION BY WED
MORN AS THE SFC HI MOVES S OF THE FA TUE NGT. WINDS...WHICH WILL
BEGIN NEAR CALM TUE EVE WILL SHIFT TO THE LGT SW LATE TUE NGT AS
SKIES BECOME PTLY CLDY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WITH THE UPPER RIDGE FLEXING SW TO NE OVR THE FA...TEMPS WILL
RAPIDLY RISE ON WED INTO THE 80S OVR THE REGION WITH A WSW WIND
AND PTLY TO MSLY SUNNY SKIES AS HUMIDITY RISES WITH INCREASING SFC
DWPTS REACHING BACK INTO THE LOWER TO MID 60S. A VERY WEAK S/WV
AND ASSOCIATED WEAK COLD FRONT COULD RESULT IN ISOLD TO SCT
MID/LATE AFTN AND ERLY EVE TSTMS...MSLY ACROSS THE N. WHATS LEFT
OF THIS BOUNDARY WILL LIKELY SLIDE S AND W OF THE FA BY
THU...PERHAPS BEING A FOCUS OF SCT AFTN SHWRS/TSTMS ALG THE SW
FLANK OF OUR FA ACROSS WRN AND CNTRL ME. HI TEMPS OVR E CNTRL AND
INTERIOR DOWNEAST AREAS WILL CONT VERY WARM SIMILAR TO WED...BUT
ACROSS THE N SHOULD BE A LITTLE COOLER (UPPER 70S TO LOWER 80S)
AND DRIER AS SFC DWPTS FALL BACK INTO THE 50S BEHIND THE WEAK
COLD FRONT.
AFTWRDS FOR FRI AND SAT...LONGER RANGE MODELS DISAGREE CONCERNING
WHETHER THE FA WILL BE IN SHALLOW COOLER AIR FROM NE CANADA OR
MUCH WARMER AND MORE HUMID AIR FROM THE UPPER MIDWEST. GIVEN
THAT EVEN MINOR DIFFERENCES IN TMG OF WEAK S/WVS WILL BE PIVOTAL
IN DETERMINING THE TMG OF FRONTS ACROSS THE FA...WE KEPT CLOSE TO
THE SUPERBLEND AVG OF LONGER RANGE MODELS FOR HI TEMPS ON FRI AND
SAT WHICH STILL GIVES THE REGION ABV NORMAL TEMPS...BUT WITH LOW
CERTAINTY ON EITHER DAY. FOR NOW...WE KEPT FCST RN POPS EACH DAY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: MAINLY VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
ONLY EXCEPTION WILL BE BRIEF MVFR CEILINGS WILL BE POSSIBLE AT THE
NORTHERN TERMINALS EARLY THIS MORNING AS SHOWERS MOVE THROUGH.
SHORT TERM: MAINLY VFR...XCPT PERHAPS A BRIEF PD OR TWO OF MVFR
CLGS/VSBYS OVR NRN TAF SITES WITH HEAVIER SHWRS ON MON AND AGAIN
WED AFTN/ERLY EVE.
&&
.MARINE...
NEAR TERM: NO HEADLINES WILL BE NEEDED OVER THE WATERS TODAY OR
TONIGHT AS HIGH PRESSURE REMAINS POSITIONED ACROSS THE REGION.
SHORT TERM: NO HDLNS AND LGT SEAS XPCTD...REACHING 2 TO 3 FT OVR
OUR OUTER MZS AND 1 TO 2 FT ALG THE NEAR SHORE WATERS. ABOUT 90
AND 70 PERCENT RESPECTIVELY OF WW3 WV GUIDANCE WAS USED TO PRODUCE
FCST WV HTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1123 AM EDT SUN AUG 30 2015
.UPDATE...
HELD THE LINE FROM THE MORNING FORECAST PACKAGE ON THUNDERSTORM
POTENTIAL FOR THIS AFTERNOON. THE SUBDUED/ISOLATED MENTION REMAINS
ON TARGET MAINLY AS DAYTIME HEATING ACTS ON LINGERING LOW LEVEL
MOISTURE. THE 12Z DTX SOUNDING INDICATES THE BEGINNING OF CAP
DEVELOPMENT UNDER INFLUENCE OF SUBSIDENCE TRAILING THE UPPER LEVEL
TROUGH AXIS AS IT EXITS LOWER MICHIGAN. THE RACE IS ALSO ON
BETWEEN SURFACE HEATING AND NEGATIVE THETA-E ADVECTION AROUND 850
MB. THIS PROCESS WILL GRADUALLY REDUCE THE DEPTH OF MOISTURE
INDICATED IN THE SOUNDING. MAINTENANCE OF ISOLATED THUNDERSTORM
COVERAGE ALONG AND SOUTH OF INTERSTATE 69 IS THEN A NOD TO CONTINUED
DEPICTION OF DEVELOPMENT IN EVEN THE MOST RECENT MESOSCALE MODEL
RUNS. THE LATEST RAP SUGGESTS SURFACE BASED CAPE RISING TO ABOUT
1200 J/KG AS LONG AS DEWPOINT CAN HOLD IN THE MID 60S. CONVECTION
MAY END UP BEING MORE OF A MODERATE DEPTH SHOWER RATHER THAN A
THUNDERSTORM ASSUMING MID LEVEL SUBSIDENCE CONTINUES TO EVOLVE. IF
CONVECTION CAN BREACH THE WARM LAYER AND REACH -20C/THUNDER THEN
SOME POTENTIAL FOR PRECIP LOADED WIND GUSTS WILL EXIST DUE TO
ENTRAINMENT OF MID TO UPPER LEVEL DRY AIR INDICATED IN THE
SOUNDING AND WV IMAGERY. OTHERWISE...JUST A LOCALLY HEAVY DOWNPOUR
EXPECTED THROUGH THE PEAK HEATING CYCLE INTO EARLY EVENING.
&&
.AVIATION...ISSUED 545 AM EDT SUN AUG 30 2015
LINGERING LOW LEVEL MOISTURE WITH DRY AIR IN THE MID LEVELS
ATTEMPTING TO MOVE INTO SOUTHEAST MICHIGAN TODAY. ISOLATED-SCATTERED
LIGHT SHOWERS STILL AROUND...WITH A REMOTE CHANCE OF A THUNDERSTORM.
FORECAST CEILINGS WILL HINGE ON THE EXTENT OF LOWER CLOUDS AND FOG
DEVELOPING NEAR SUNRISE. WHATEVER IFR FOG AND STRATUS AROUND WILL
GRADUALLY LIFT INTO LOW VFR DECK BY EARLY AFTERNOON...AND LIKELY
LINGERING MOST OF THE DAY. CLEARING SKIES DURING THE EVENING HOURS
EXPECTED TO YIELD FOG AGAIN LATE TONIGHT...BUT SHOULD BE
SHALLOWER...AND HAVE GONE WITH 3SM FOR NOW.
FOR DTW...SHOULD HAVE MVFR FOG TO START THE DAY...BUT HAVE BACKED
OFF ON THE IFR CEILING. CEILINGS AROUND OR JUST BELOW 5000 FEET
EXPECTED THROUGH THE DAY...BUT CLEARING DURING EARLY EVENING HOURS.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CIG AOB 5KFT TODAY.
&&
.PREV DISCUSSION...ISSUED 302 AM EDT SUN AUG 30 2015
SHORT TERM... TODAY AND TONIGHT
MOIST AIRMASS IN PLACE OVER SOUTHEAST MICHIGAN EARLY THIS
MORNING...AS 00Z DTX SOUNDING REVEALED A 700 MB DEW PT OF 4
C...850 MB DEW PT OF 12 C...ALONG WITH A PW VALUE OF 1.6 INCHES.
SHEARED OUT SHORTWAVE/PV WILL SLOWLY BE EXITING THE CENTRAL GREAT
LAKES...BUT LAST VESTIGE OF 850-700 MB THETA-E AXIS STILL PROVE
SUFFICIENT FOR ISOLATED-SCATTERED LIGHT SHOWERS THIS MORNING BEFORE
DRIER AIR ATTEMPTS TO SLOWLY FILTER INTO SOUTHERN LOWER MICHIGAN
THROUGH THE DAY...BUT UNCERTAIN WE WILL BE ABLE TO SCOUR OUT THE LOW
LEVEL MOISTURE...AS 00Z NAM MAINTAINS HIGHER RH VALUES IN THE 925-
850 MB LAYER. WITH 500 MB TEMPS FALLING UP TO 2 C DEGREES...SURFACE
BASED INSTABILITY/CAPE IS PROGGED TO RISE TO AROUND 750 J/G...PER
00Z GFS...BUT 1000-2000 J/KG PER 00Z NAM...AS SURFACE DEW PTS REMAIN
SOLIDLY IN THE 60S. HOWEVER...700 MB TEMPS WILL BE RISING TO AROUND
9 C NORTH OF I-69...WHICH SHOULD ULTIMATELY PROVIDE A SUFFICIENT
CAP. SOUTH OF I-69 IS WHERE COOLER MID LEVELS PERSIST LONGER AND
WHERE A SLIGHT/LOW CHANCE OF SHOWERS/THUNDERSTORMS WILL BE CARRIED
FOR THE AFTERNOON HOURS. MINIMAL CONCERNS FOR SEVERE WEATHER WITH
WEAK WIND FIELDS...IF IN FACT A CELL IS EVEN ABLE TO GO UP.
BASED ON PESKY CLOUDS EXPECTED TODAY...WILL HOLD MAXES AROUND 80
DEGREES...BUT POTENTIAL FOR WARMER TEMPS IS THERE WITH 850 MB TEMPS
OF 16 C. LOW LEVEL MOISTURE/ELEVATED DEW PTS HOLDING IN THE LOWER
60S TONIGHT SHOULD SET THE STAGE FOR SOME FOG AS SKIES BECOME MAINLY
CLEAR WITH LIGHT/CALM WINDS IN PLACE.
LONG TERM...MONDAY THROUGH SATURDAY
SOUTHERN PLAINS UPPER RIDGE WILL UNDERGO STEADY DOWNSTREAM
AMPLIFICATION OVER THE NEXT 48 HOURS...IN RESPONSE TO SUBSTANTIAL
HEIGHT FALLS WORKING INTO THE WESTERN CONUS. THIS PROCESS WILL
EFFECTIVELY CENTER AN UPPER LEVEL ANTICYCLONE OVER SE MICHIGAN BY
MONDAY. A HIGH DEGREE OF STABILITY UNDER THE ATTENDANT MINIMUM IN
THETA-E AND AN ELEVATED MID LEVEL TEMPERATURE PROFILE WILL YIELD
PLENTY OF SUNSHINE...AND NO REAL OPPORTUNITY FOR CONVECTIVE
DEVELOPMENT. THE INCREASE IN THICKNESSES AND GENERALLY LIGHT
SOUTHWEST FLOW WILL PROVIDE A NOTED UPTICK IN TEMPERATURES RELATIVE
TO TODAY...WITH DAYTIME READINGS REACHING THE MID 80S.
UPPER RIDGING TO REMAIN THE PRIMARY GOVERNING FEATURE THROUGH THE
REMAINDER OF THE UPCOMING WORK WEEK. THIS WILL TRANSLATE INTO A
RELATIVELY BENIGN STRETCH OF WEATHER CONDITIONS...WITH ABOVE NORMAL
WARMTH AND LIMITED /IF ANY/ POTENTIAL FOR CONVECTION. THE RIDGE
AXIS MAY LOSE SOME DEFINITION BY MIDWEEK AS A WEAK HEIGHT FALL
CENTER DRIFTS THROUGH THE OHIO VALLEY...WITH A CORRESPONDING GRADUAL
INCREASE IN THETA-E DURING THIS TIME. PLAUSIBLE SCENARIO THAT WEAK
CVA WORKING THROUGH ALONG THE NORTH END OF THIS FEATURE PROVIDES A
LOCALIZED/BRIEF WINDOW FOR ASCENT...MEDIUM RANGE GUIDANCE STILL
CENTERING ON WEDNESDAY. LOW END POTENTIAL AT THIS STAGE GIVEN AN
OTHERWISE LACKLUSTER LOOKING FORCING/WIND FIELD.
MARINE...
BENIGN MARINE WEATHER WILL CONTINUE ACROSS THE GREAT LAKES REGION
THROUGH MUCH OF THE UPCOMING WEEK. A STRONG RIDGE OF UPPER LEVEL
HIGH PRESSURE WILL MAINTAIN LIGHT FLOW AND A GENERAL SOUTHWEST WIND
DIRECTION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......BT
AVIATION.....SF
SHORT TERM...SF
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
932 AM CDT SUN AUG 30 2015
.UPDATE...CURRENT FORECAST IS ON TRACK AND NO CHANGES ARE ANTICIPATED
AT THE MOMENT. UPPER LEVEL LOW OVER SOUTH AL BEGINNING TO LIFT OUT TO
THE NE...BUT STILL APPEARS CLOSE ENOUGH TO PROMOTE CONVECTIVE
DEVELOPMENT IN THE EAST THIS AFTERNOON WHERE MUCH DEEPER MOISTURE
REMAINS IN PLACE. THE HRRR AGREES WITH THIS SCENARIO AT IT DEVELOPS A
GOOD PEPPERING OF SHOWERS AND A FEW THUNDERSTORMS IN THAT PORTION OF
THE FORECAST AREA THIS AFTERNOON./26/
&&
.AVIATION...THE BRIEF MVFR CIGS THAT DEVELOPED OVER EAST MISSISSIPPI
THIS MORNING HAVE LIFTED AND VFR CONDS WERE BEING OBSERVED AT ALL
TAF SITES AT 14Z. VFR CONDS ARE EXPECTED TO PREVAIL THROUGH THIS
EVENING AREAWIDE. A POSSIBLE EXCEPTION WL BE MEI-GTR THIS AFTN/EVNG
DUE TO ISOLD TO SCT TSRA DEVELOPMENT. A BRIEF PERIOD 10Z-12Z MON OF
MVFR VSBYS WL BE PSBL ESPECIALLY IN THE EAST. /22/
&&
.PREV DISCUSSION... /ISSUED 412 AM CDT SUN AUG 30 2015/
DISCUSSION...
TODAY THROUGH MONDAY NIGHT...
WATER VAPOR IMAGERY REVEALS A WELL-DEFINED UPPER LOW MOVING SLOWLY
ACROSS THE CENTRAL GULF COAST THIS MORNING. CYCLONIC FLOW IS HELPING
TO TRANSPORT SUBSTANTIAL DEEP LAYER MOISTURE (PRECIPITABLE WATER >
1.5 INCHES) AROUND THE NORTHERN SIDE OF THE LOW AND THIS IS HELPING
TO INCREASE CONVECTIVE RAINFALL POTENTIAL OVER NORTHEAST
MISSISSIPPI...ESPECIALLY FOR LATER IN THE AFTERNOON DURING PEAK
HEATING. INSTABILITY IS POOR AND THUNDERSTORMS THAT DEVELOP ARE NOT
EXPECTED TO BE OVERLY INTENSE...BUT SLOW STORM MOTION COULD YIELD
LOCALLY HEAVY RAINFALL. FOR MOST OF THE AREA...DRY WEATHER WILL
CONTINUE.
MODELS FORECAST THE LOW TO MOVE NORTHEAST AND LIFT OUT AS AN
UPSTREAM WAVE DIGS SOUTHWARD ACROSS THE OZARK REGION. SUBSIDENCE IN
BETWEEN THESE FEATURES SHOULD MAKE FOR DRIER WEATHER MONDAY.
OTHERWISE...THE END OF AUGUST WILL BRING TYPICAL LATE SUMMER HEAT
AND HUMIDITY WITH AFTERNOON HEAT INDICES REACHING THE MID 90S. /EC/
TUESDAY THROUGH NEXT SUNDAY...
GLOBAL MODELS AND ENSEMBLES CONTINUE TO SHOW A PATTERN CHANGE OVER
THE CONUS FOR THE PERIOD WITH AN UPPER LEVEL TROUGH OVER WESTERN
CONUS AND STRONG SUBTROPICAL UPPER RIDGING OVER THE EASTERN CONUS.
OVER THE REGION A WEAK CUT OFF UPPER LOW WILL MEANDER ACROSS THE
REGION UNDER THE MEAN UPPER RIDGE. MEAN MOISTURE ACCORDING TO THE GFS
WILL GRADUALLY BUILD ACROSS THE REGION AS PWATS PUSH TO UP TO 2 PLUS
INCH RANGE BY FRIDAY...EXTENDING FOR THE REST OF THE PERIOD. THIS
WILL BRING LOW END CHANCES OF CONVECTION FOR THE WORK WEEK AS
MIDLEVEL CAPPING WILL INHIBIT DEVELOPMENT WITHOUT ANY FOCUSED LIFT.
AS WE PUSH INTO FRIDAY THROUGH THE WEEKEND CHANCES OF CONVECTION
SLOWLY INCREASE WE DEVELOP DEEPER MOISTURE ACCORDING TO THE GFS OVER
THE REGION. GFS MODEL CROSS SECTIONS SHOWS BETTER VERTICAL LIFT
DURING THE TIME. THE EURO MODEL WAS NOT AS DEEP WITH THE MOISTURE
OVER THE WEEKEND. IT SHOWED SOME MID TO UPPER LEVEL DRYING. SO OPTED
TO KEEP LOWER END POPS FOR THE WEEKEND. A NORTHERN STREAM SHORT WAVE
WILL HELP TO FLATTERN MEAN SUBTROPICAL RIDGE OVER MOST OF THE CONUS
BY THE END OF THE PERIOD.
DAILY HIGHS WILL AVERAGE IN THE 91-95 RANGE WITH LOWS IN THE LOWER
70S AS MORE HUMID CONDITIONS WILL COME BACK TO THE REGION. WITH THIS
IN MIND MADE SMALL ADJUSTMENTS TO CURRENT FORECAST BASED ON NEW
MODEL GUIDANCE./17/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 92 68 92 69 / 12 7 7 4
MERIDIAN 88 65 91 67 / 29 7 5 5
VICKSBURG 94 66 94 67 / 4 7 6 5
HATTIESBURG 93 68 94 70 / 9 6 6 3
NATCHEZ 90 68 90 69 / 4 7 10 5
GREENVILLE 93 69 93 70 / 8 9 5 5
GREENWOOD 92 67 92 68 / 20 8 5 6
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
26/22/EC/17
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
646 AM CDT SUN AUG 30 2015
.DISCUSSION...
30/12Z TAF ISSUANCE.
&&
.AVIATION...
LIFR CONDITIONS IN FOG/STRATUS ARE EXPECTED ACROSS NORTHERN
OKLAHOMA TERMINALS THROUGH 15Z. WILL ALSO MENTION MVFR FOG OVER
CENTRAL OKLAHOMA TERMINALS OF KOKC/KOUN FIRST FEW HOURS OF
FORECAST. OTHERWISE VFR FORECAST WITH LIGHT NORTHERLY WINDS
BECOMING LIGHT SOUTHERLY LATE IN THE AFTERNOON AND TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 406 AM CDT SUN AUG 30 2015/
DISCUSSION...
MAIN ADJUSTMENT TO GOING FORECAST PACKAGE WAS TO ADD FOG FOR THIS
MORNING ACROSS AREAS NORTH OF I-40. THE MOST WIDESPREAD AND
POSSIBLY DENSE FOG WILL BE OVER FAR NORTH/NORTHWEST OKLAHOMA
NEAREST LOW LEVEL RIDGE AXIS. CONFIDENT THAT THERE WILL BE FOG BUT
JUST NOT SURE HOW WIDESPREAD ANY DENSE FOG WILL BE. THE MOST
AGGRESSIVE MODELS...WRF AND HRRR KEEP A MAJORITY OF DENSE FOG UP
IN KANSAS THROUGH 9 AM. DENSE FOG ADVISORY NOT ANTICIPATED AT THIS
POINT BUT WE WILL WATCH TRENDS AND ISSUE AS NEEDED. POPS WERE ALSO
CONTINUED THROUGH TODAY ACROSS SOUTHEAST CWA NEAR MID-LEVEL SHEAR
AXIS AND EFFECTIVE SYNOPTIC BOUNDARY.
TODAYS TEMPS WERE COOLED A BIT FROM PREVIOUS FORECAST AS WELL.
INITIALIZATIONS CAME IN A FEW DEGREES COOLER MAINLY OVER NORTHERN
AND WESTERN OKLAHOMA...AND WITH PLUME OF HIGH LEVEL SMOKE THIS
SOUNDS REASONABLE. GFS AND ECM HAVE TRENDED WEAKER WITH THE UPPER
LEVEL RIDGE AND HAVE GENERALLY UNDERFORECAST STRENGTH/PERSISTENCE
OF LONGWAVE TROUGH AXIS JUST TO OUR EAST. THIS WILL YIELD SLIGHTLY
COOLER TEMPS THROUGH THE WEEK MOST AREAS AND ALTHOUGH POPS ARE TOO
LOW TO MENTION...CANNOT RULE OUT AN ISOLATED SHOWER OR WEAK STORM
ESPECIALLY FAR NORTHWEST OKLAHOMA CLOSER TO POSSIBLE HIGH PLAINS
REMNANTS AND FAR SOUTHEAST OKLAHOMA CLOSER TO UPPER TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 93 70 / 10 0 0 0
HOBART OK 92 67 97 71 / 10 0 0 0
WICHITA FALLS TX 96 71 97 72 / 10 0 0 0
GAGE OK 91 63 96 69 / 10 0 0 0
PONCA CITY OK 88 67 93 70 / 10 0 0 0
DURANT OK 94 71 95 71 / 20 10 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/11/11
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1031 AM CDT SUN AUG 30 2015
.UPDATE...WHILE VSBYS HAVE SHOWN IMPROVEMENT ALLOWING FOR DENSE
FOG ADVISORY TO EXPIRE...STRATUS DECK LINGERS ESP ACRS SE WI. RAP
SOUNDINGS APPEAR TO BE DRYING THINGS OUT TOO QUICKLY SO HAVE
BOOSTED SKY GRIDS AND TWEAKED TEMPS DOWN TO ACCOUNT FOR THESE
TRENDS. DUE TO INCREASING SSW WINDS OFF THE DECK TONIGHT DENSE
FOG MAY NOT BE AS MUCH OF AN ISSUE...BUT OVERALL PERSISTING LIGHT
WIND REGIME...LITTLE SURFACE LOW AND STILL PLENTY OF MOISTURE WILL
LEAD TO MORE FOG.
PC
&&
.AVIATION/18Z TAFS/...VSBL SATELLITE ANIMATION SHOWS PERSISTENT
STRATUS DECK NOT SHOWING MUCH SIGNS OF EROSION ACROSS SE WI AND
PORTIONS OF SC WI. LINGERING LIFR CIGS SHOULD LIFT SOME WITH TIME.
OVERALL EXPECTING A TREND TOWARDS MVFR CIGS WITH IFR CIGS HANGING
ON A BIT LONGER IN THE ERN CWA. RAP SOUNDINGS LOOK TOO AGGRESSIVE
IN CLEARING THINGS OUT SO STAYING MORE PESSIMISTIC ON OVERALL
CLOUD COVERAGE. MORE FOG/STRATUS EXPECTED TONIGHT WITH LIGHT WIND
REGIME AND LOW LEVEL MOISTURE. HOWEVER SLIGHTLY STRONGER WINDS OFF
THE DECK MAY LIMIT THE COVERAGE OF DENSE FOG.
PC
&&
.MARINE...A DENSE FOG ADVISORY IS IN EFFECT UNTIL 3 PM AS A RELATIVELY
WARM AND HUMID AIRMASS IS OVER THE COOLER WATERS OF LAKE MICHIGAN.
SOME FOG MAY CONTINUE TO PERSIST LATE THIS AFTERNOON AND TONIGHT.
THE DENSE FOG ADVISORY MAY NEED TO BE EXTENDED IF THERE IS ENOUGH
DENSE FOG PRESENT.
GEHRING
&&
.PREV DISCUSSION... /ISSUED 336 AM CDT SUN AUG 30 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
FORCING WITH MID LEVEL TROUGH AND CONVERGENCE ALONG INVERTED SURFACE
TROUGH FINALLY MOVED FAR ENOUGH TO THE SOUTHEAST LATE SATURDAY
EVENING TO TAKE ANY DRIZZLE/VERY LIGHT RAIN OUT OF SOUTHERN
WISCONSIN. MAINLY 3-5 MILE FOG HAS FORMED WITH LIGHT WINDS AND
ABUNDANT LOW-LEVEL MOISTURE AS SURFACE HIGH PRESSURE HAS BECOME
CENTERED OVER STATE.
HAVE ISSUED A DENSE FOG ADVISORY UNTIL 14Z FOR THE NORTHERN-MOST
COUNTIES WHERE 1/4 MILE VSBYS HAVE BECOME WIDESPREAD AFTER LOWER
CLOUD COVER THAT STILL LINGERS OVER THE REST OF THE AREA CLEARED
OUT. SOME LOCALLY DENSE FOG HAS FORMED...MAINLY IN THE LAKESHORE
COUNTIES AND THE WISCONSIN RIVER VALLEY. WILL CONTINUE TO MONITOR
THE REST OF THE FORECAST AREA FOR FURTHER DEVELOPMENT...THOUGH THE
CLOUD DECK IS PREVENTING ADDITIONAL COOLING THAT WOULD PRODUCE
ADDITIONAL WIDESPREAD DENSE FOG. WILL CONTINUE TO HANDLE THESE OTHER
LOCATIONS WITH SPS ISSUANCES FOR NOW AND WATCH FOR NEED FOR AN
EXPANSION OF THE NORTHERN ADVISORY.
IN SPITE OF DECENT 850 AND 925 MB TEMPERATURE ADVECTION AS MID-UPPER
LEVEL RIDGING BUILD IN...WARMING WILL BE LIMITED TODAY AS FORECAST
SOUNDINGS AND LOW-LEVEL RH FORECASTS INDICATE LOW CLOUDS WILL BE
SLOW TO BREAK UP AFTER FOG LIFTS. HAVE BACKED OFF HIGH TEMPERATURES
A FEW DEGREES...BUT DO EXPECT SOME SUNSHINE THIS AFTERNOON
HIGH SLIDES OFF TO THE SOUTHEAST BY THIS EVENING...WITH RESULTING
SOUTHWEST FLOW PROVIDING SOME MIXING...THOUGH DECOUPLING WITH
SHALLOW INVERSION WILL PROBABLY ALLOW FOR SOME AREAS OF FOG AGAIN
TONIGHT...THOUGH EXPECT ENOUGH TURBULENT MIXING TO PREVENT
WIDESPREAD DENSE FOG.
MONDAY THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM
SURFACE HIGH PRESSURE AND UPPER RIDGING IS EXPECTED TO GENERALLY
REMAIN PARKED OVER THE GREAT LAKES THROUGH THIS UPCOMING WEEK.
THIS SETUP SHOULD PUT SOUTHERN WISCONSIN IN A PERSISTENT MILD AND
MOIST SOUTHERLY FLOW. MODELS ARE SHOWING A WEAK WAVE OR TWO COULD
BRING A FEW STORMS AT SOME POINT DURING THE WEEK...SO HAVE SOME
LOW POPS IN THERE. NOT A LOT OF CONFIDENCE IN POPS DURING ANY ONE
PERIOD. SHOULD BE DRY FOR MUCH OF THE TIME.
MAIN STORY THIS WEEK WILL BE TEMPS WARMING TO ABOVE NORMAL
VALUES. HAVE BUMPED TEMPS UP ABOVE CONSENSUS OF MODELS AS 925 MB
TEMPS AROUND 25C SUGGEST HIGHS IN AT LEAST THE UPPER 80S TO AROUND
90 MOST DAYS. IT WILL PROBABLY BE A BIT COOLER NEAR LAKE MICHIGAN
AT TIMES WHEN SOUTH TO SOUTHWEST WINDS ARE NOT STRONG ENOUGH TO
KEEP THE LAKE BREEZE OFFSHORE.
AVIATION/12Z TAFS/...WILL SEE MVFR/IFR FOG AND CIGS CONTINUE INTO
THE MID TO LATE MORNING HOURS WITH AND ABUNDANT LOW LEVEL MOISTURE
AND HIGH PRESSURE CENTERED OVER STATE BRINGING WEAK FLOW. WEAK WAA
AND SOME MIXING WILL BRING VSBYS UP AND EVENTUALLY SCATTER OUT THE
CLOUDS THIS AFTERNOON. WILL SEE THE POTENTIAL FOR MVFR FOG...WITH
SOME IFR VSBYS TONIGHT...THOUGH 10 KNOT PLUS WINDS JUST OFF THE
SURFACE SHOULD PROVIDE ENOUGH MIXING TO PREVENT WIDESPREAD LOW
VSBYS.
MARINE...LIGHT WINDS WITH HIGH PRESSURE CENTERED OVER REGION AND A
MOIST AIRMASS REMAINING IN PLACE WILL KEEP A DENSE FOG ADVISORY
UNTIL 10 AM TODAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
413 PM MDT SUN AUG 30 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM MDT SUN AUG 30 2015
AT PRESENT TIME ...STILL BARELY UNDER THE INFLUENCE OF A STRONG/VERY
WARM AND MOSTLY DRY POSITIVE TILT UPPER RIDGE. 700-500 MB RIDGE AXIS
IS NOW SHIFTED EAST OF THE FRONT RANGE AS PER LATEST RAP MODEL WITH
FLOW ALOFT BECOMING WEST-SOUTHWESTERLY. UPSTREAM OVER UTAH/WESTERN
WYOMING...STRONGER SWLY FLOW ALOFT WITH AN 80-90KT JET CORE IS
PROGGED TO SLOWLY TRANSLATE EASTWARD OVER NORTHERN COLORADO NEXT 24
HOURS. MID/HIGH-LEVEL MOISTURE ALIGNED WITH THIS JET WILL SPREAD
OVER NORTH CENTRAL COLORADO TONIGHT AND NORTHEAST COLORADO ON
MONDAY. MODEL CROSS SECTIONS AND SOUNDINGS SHOW CONDENSATION LEVELS
LOWERING OVER THE HIGH COUNTRY AS A BAND OF SHOWERS AND T-STORMS
ALIGNED WITH A WEAK MID-LEVEL PERTABATION PASSES OVER THE AREA THIS
EVENING. AT THE SAME TIME THIS DISTURBANCE LIFTS EAST-NORTHEAST
ACROSS THE REMAINDER OF THE FORECAST AREA...SHOULD SEE A WEAK SFC
COLD FRONT SLIDING SOUTH OUT OF WYOMING. PRESSURE RISES BEHIND
THE FRONT DO NOT APPEAR TO BE ALL THAT STRONG AND WITH THE PRE-
FRONTAL ENVIRONMENT AS DRY AS IT IS...ITS PROBABLY NOT UNTIL NELY
BNDRY LAYER WINDS KICK IN AFTER FRONTAL PASSAGE WHEN PRECIP CHANCES
SHOULD GO UP EAST OF THE MTNS. AT THIS TIME...THE POORLY ORGANIZED
FRONT COULD SLIP INTO THE DENVER AREA BY 15Z TOMORROW MORNING...WITH
A RE-ENFORCING SURGE OF SLIGHTLY COOLER AND WETTER NELY FLOW BY
ABOUT MIDDAY. MOSTLY CLOUDY TO OVERCAST SKIES AND SCATTERED POPS ARE
IN ORDER FOR MONDAY. ONE OTHER ISSUE...THIS FRONTAL SURGE IS LIKELY
TO USHER IN THE NEXT BATCH OF WILDFIRE SMOKE FORM WILDFIRES TO OUR
NORTH AND NORTHWEST. NWS AIR QUALITY FORECAST GUIDANCE NOT
INDICATING MUCH IN THE WAY OF SFC AND COLUMN SMOKE ALONG THE FRONT
RANGE...BUT SHOULD ANY RESTRICTION DUE TO SMOKE ITS MORE LIKELY TO
OCCUR LATE IN THE DAY. TEMPERATURES QUITE MILD TONIGHT...WHEN COOLING
OFF BY SEVERAL DEGREES TOMORROW. EXPECT MAX TEMPS ON MONDAY TO
BE NEAR TO SLIGHTLY ABOVE AVERAGE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM MDT SUN AUG 30 2015
CLOUDS AND SHOWERS/STORMS WILL GRADUALLY CLEAR FROM WEST TO EAST
MONDAY NIGHT. ON TUESDAY SLIGHT DRYING AND WARMING WILL LEAD TO
DIURNAL CONVECTION OVER THE MOUNTAINS THAT SHOULD PROGRESS NICELY
EASTWARD INTO THE EVENING. CAPES ARE RATHER LOW UNTIL YOU GET OUT
ON THE PLAINS...COULD BE A LOW THREAT OF SEVERE WIND/HAIL OUT EAST
IN THE EVENING.
DRIER AIR COMES IN WEDNESDAY. A LITTLE WIND IN THE MOUNTAINS
SHOULD PEAK TUESDAY NIGHT...BUT ENOUGH LEFT WEDNESDAY FOR ELEVATED
FIRE DANGER ESPECIALLY IN NORTH AND MIDDLE PARKS. THERE SHOULD BE
A MINIMUM OF CONVECTION ON WEDNESDAY AND ESPECIALLY THURSDAY WITH
THE WARMING ALOFT AND DRYING.
PRETTY GOOD MODEL AGREEMENT ON THE SOUTHWEST FLOW CONTINUING
THROUGH SATURDAY...WITH JUST A LITTLE MOISTURE POSSIBLY CREEPING
IN AT LOW LEVELS ON THE PLAINS AND ALOFT FROM THE SOUTHWEST. STILL
LOOKS RELATIVELY DRY OVERALL.
SOME DISAGREEMENT ON THE STRUCTURE OF THE TROUGH OVER THE
NORTHWEST AND SHORTWAVES MOVING ACROSS THE NORTHERN ROCKIES NEXT
WEEKEND...BUT NOT BAD FOR THAT TIME RANGE. MOST OF THE IMPACT IS
HEADED NORTH OF US...BUT IT SHOULD PUSH A SURGE OF COOLER AND
MOISTER...AND POSSIBLY SMOKIER...AIR SOMETIME THIS WEEKEND. THERE
ARE ALSO HINTS OF SOME SUBTROPICAL MOISTURE COMING UP FROM THE
EASTERN PACIFIC...BUT THIS MAY STAY SOUTH AND EAST OF US. THERE
COULD BE AN UPSWING IN CONVECTION FROM SUNDAY INTO EARLY NEXT WEEK
AS THE MOISTURE INCREASES...BUT WE WILL STILL BE FIGHTING THE
STABILITY FROM THE WARMTH ALOFT. MODELS SEEM TO KEEP MOST OF THE
PRECIPITATION FURTHER SOUTH. FOR NOW THE COOLING AND SLIGHT
INCREASE IN POPS FOR SUNDAY WILL DO...MAYBE MORE AFTER
THAT...MAYBE NOT.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z MONDAY LATE AFTERNOON)
ISSUED AT 400 PM MDT SUN AUG 30 2015
VISIBILITIES HAVE IMPROVED IN THE DENVER AREA TODAY WITH LIGHT
SWLY TRANSPORT WINDS AND EFFICIENT MIXING OF THE BOUNDARY LAYER
DUE TO STRONG HEATING TODAY. LATER TONIGHT...COULD SEE A GRADUAL
SHIFT TO LIGHT NORTHERLY WINDS WHICH MAY FUNNEL DOWN SOME SMOKE
POISED JUST NORTH OF THE WYOMING LINE. BEFORE THEN SOUTH-SOUTHEAST
WINDS WILL PREVAIL AT SPEEDS GENERALLY UNDER 12KTS. MEANWHILE THIS
EVENING STILL ANTICIPATING A T-STORM OR TWO TO MOVE OFF THE FRONT
RANGE FOOTHILLS. THESE HIGH BASED AND MOSTLY DRY STORM CELLS WILL
HAVE THE POTENTIAL TO PRODUCE GUSTS IN THE 25-30KT RANGE. LATER
TONIGHT...COULD SEE A FEW MORE LIGHT RAIN SHOWERS AND PERHAPS A
T-STORM OR TWO MOVING ACROSS THE AREA IN ADVANCE OF OF A WEAK
UPPER AIR DISTURBANCE AND SURFACE COLD FRONT. LATEST INDICATIONS
POINT TO A WEAK FRONTAL SURGE IN THE METRO AREA AROUND 15Z
TOMORROW MORNING...WITH A SOMEWHAT STRONGER PUSH OF SLIGHTLY
COOLER AND MOIST AIR ON NELY WINDS OF 15 TO 25KTS AROUND 18Z.
AFTER WHICH SHOULD SEE PRECIP CHANCES RISE IN THE METRO AREA WITH
SCATTERED SHOWERS AND ISOLATED T-STORMS. IN ADDITION...THE GUSTY
POST-FRONTAL WINDS COULD USHER IN MORE WILDFIRE SMOKE WHICH COULD
POSSIBLY LOWER VSBYS TO 5-6 MILE RANGE BY LATE AFTERNOON...ASSUMING
IT DOESN/T MIX OUT WITH THE SHOWERY PRECIPITATION.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM...GIMMESTAD
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
133 PM EDT SUN AUG 30 2015
.SYNOPSIS...
HIGH PRESSURE REMAINS OFFSHORE AHEAD OF AN APPROACHING TROUGH
WHICH WILL CROSS THE AREA TONIGHT. LOW PRESSURE THEN PASSES TO THE
NORTH ACROSS EASTERN CANADA ON MONDAY...SENDING A WEAK BACK DOOR
COLD FRONT THROUGH THE AREA TUESDAY MORNING. HIGH PRESSURE WILL
REMAIN IN CONTROL FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MINOR CHANGES MADE TO FORECAST DATABASE TO BETTER MATCH OBSERVED
TRENDS. TEMPERATURES SLIGHTLY INCREASED ACROSS THE INTERIOR AND
TEMPERATURES ELSEWHERE WERE PRETTY MUCH ON TRACK. DEWPOINTS WERE
INCREASED SLIGHTLY AS WELL ACROSS THE COASTAL SECTIONS. POPS WERE
KEPT AT SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS NORTH OF NYC.
MESOSCALE MODELS NOT SHOWING MUCH CONVECTION WITH HRRR MODEL
SHOWING RELATIVELY MORE CONVECTIVE COVERAGE.
THE TREND WILL BE FOR WARMER AND INCREASINGLY MORE HUMID
CONDITIONS HEADING INTO THE NEW WEEK AS A HIGH AMPLITUDE RIDGE
OVER THE WESTERN U.S. MERGES WITH THE SUB TROPICAL RIDGE ALONG
THE EASTERN SEABOARD. IN BETWEEN...A WEAKNESS ACROSS THE MID
SECTION OF THE COUNTRY WILL GRADUALLY FILL...WHILE A NORTHERN
STREAM SHORT WAVE TROF PASSES THROUGH THE AREA TONIGHT. AT THE
SURFACE...THIS WILL BE REFLECTED AS A SFC TROF OR WARM FRONT...
PRECEDED BY WEAK THERMAL FORCING. THIS FORCING COMBINED WITH
MARGINAL INSTABILITY MAY BE ENOUGH FOR AN ISOLATED SHOWER AND/OR
THUNDERSTORM THIS AFT/EVE...MAINLY NORTH AND WEST OF NYC. CLOUDS
WILL ALSO SPREAD IN FROM THE NW TODAY WITH MOSTLY CLOUDY
CONDITIONS BY AFTERNOON INLAND AND PARTY SUNNY AT THE COAST.
HIGHS WILL RANGE FROM THE MID 80S NEAR THE COAST...TO AROUND 90
INLAND.
THERE IS A MODERATE RISK FOR THE DEVELOPMENT OF RIP CURRENTS
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
AFOREMENTIONED TROF/WARM FRONT MOVES THROUGH TONIGHT WITH GRADUAL
CLEARING FROM NW TO SE BY MORNING. THE UPPER LEVEL RIDGE BEGINS TO
EXPAND EASTWARD ON MON WITH WARMING TEMP PROFILES ALOFT AND A
GUSTY W/SW FLOW IN THE AFT. THIS WILL ALLOW FOR HIGHS A FEW
DEGREES WARMER THAN ON SUN...WITH READINGS TOPPING OUT IN THE
LOWER 90S INLAND.
A WEAK BACK DOOR COLD FRONT THEN PASSES THROUGH MON NIGHT AS LOW
PRESSURE PASSES WELL TO THE NORTH AND EAST ACROSS THE CANADIAN
MARITIMES. NOT MUCH RELIEF THOUGH FOR TUE WITH PERHAPS A DEGREE
OR TWO SHAVED OFF OF MON HIGHS. LOWS WILL RANGE FROM THE LOWER TO
MID 60S INLAND...TO 70 TO 75 NYC METRO. THESE READINGS ARE STILL
WELL ABOVE NORMAL. IT WILL ALSO BE MUGGY WITH DEW POINTS WELL INTO
THE 60S. HEAT INDEX VALUES LOOK TO REMAIN BELOW ADVISORY CRITERIA
AT THIS TIME.
WINDS BRIEFLY GO NW TUE MORNING BEHIND THE COLD FRONT...BUT THEN
RETURN FROM THE S BY AFT AS THE FRONT LIFTS NORTHWARD AND
DISSIPATES NEARBY. SUBSIDENCE ALOFT WILL PUT A CAP ON ANY
CONVECTION DURING THIS TIME PERIOD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MAIN THEME OF THE LONG TERM PERIOD WILL BE THE CONTINUATION OF
HEAT AND HUMIDITY ACROSS THE REGION.
MODELS ARE IN GOOD AGREEMENT WITH THE H5 PATTERN ACROSS NORTH
AMERICA INTO THE MIDDLE OF THE WEEK AS AN UPPER LEVEL RIDGE
OUT WEST MERGES WITH THE SUB TROPICAL RIDGE OVER THE WESTERN
ATLANTIC. THIS WILL RESULT IN DRY AND UNSEASONABLY WARM WEATHER
THROUGH THU POSSIBLY FRI. THIS WILL DEPEND ON THE TIMING OF THE
NEXT COLD FRONT MOVING ACROSS WHICH IS CURRENTLY UNCERTAIN DUE TO
DIFFERENCES THAT DEVELOP IN THE H5 FLOW DURING THE LATTER PORTION
OF THE WEEK. COULD SEE A FEW SHOWERS OR TSTMS WITH THE FRONTAL
PASSAGE WHICH IS CURRENTLY SLATED FOR FRIDAY...FOLLOWED BY DRY
CONDITIONS AND COOLER BUT STILL ABOVE NORMAL TEMPS FOR THE
WEEKEND.
HIGHS WILL GENERALLY RANGE IN THE UPPER 80S TO LOWER 90S ACROSS THE
AREA THROUGH MUCH OF THE WEEK...THE EXCEPTION FRI/SAT WITH THE
FRONTAL BOUNDARIES IN/THROUGH THE AREA. HEAT INDICES ARE EXPECTED
TO BE CLOSE TO THE AMBIENT AIR TEMP AND ARE NOT CURRENTLY EXPECTED
TO REACH 95 DEGREES IN NYC THROUGH WED.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
A WEAK TROUGH OF LOW PRESSURE WILL CROSS THE TRI-STATE THIS
AFTERNOON AND EVENING...THEN STALL OUT SOUTH OF LONG ISLAND INTO
MONDAY.
VFR THROUGH THE TAF PERIOD.
SEABREEZES ON TRACK FOR ALL TERMINALS EXCEPT KSWF/KTEB AND
PROBABLY KEWR. ALREADY THROUGH CT TERMINALS/KISP/KJFK. QUESTION
IS TIMING FOR REMAINDER OF TERMINALS. ISOLATED GUSTS TO AROUND 15
KT POSSIBLE AT NYC METRO TERMINALS THIS AFTERNOON AS WELL.
WINDS BECOME SW AT UNDER 10 KT AT CITY TERMINALS TONIGHT AND
LIGHT AND VARIABLE ELSEWHERE. WSW- WNW WINDS AT AROUND 10 KT
DEVELOP BY LATE MONDAY MORNING- EARLY MONDAY AFTERNOON. WIND
SPEEDS COULD INCREASE TO AROUND 15 KT AT KJFK TOWARDS THE END OF
THE TAF PERIOD.
AN ISOLATED SHOWER OR THUNDERSTORM CANNOT BE RULED OUT THE LOWER
HUDSON VALLEY THIS AFTERNOON/EARLY THIS EVENING. HAVE INCLUDED A
VCSH AT KSWF TO REFLECT.
.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MONDAY AFTERNOON...VFR. WSW-W WINDS G15-20KT POSSIBLE.
.MONDAY NIGHT-WEDNESDAY NIGHT...VFR. AFTERNOON SEABREEZES
PROBABLE EACH AFTERNOON.
.THURSDAY...MOST LIKELY VFR. ISOLATED SHOWERS/THUNDERSTORMS
POSSIBLE. AFTERNOON SEABREEZES PROBABLE.
.THURSDAY NIGHT...VFR.
.FRIDAY...MOST LIKELY VFR. E WINDS G15-20KT POSSIBLE. ISOLATED-
SCATTERED SHOWERS/THUNDERSTORMS POSSIBLE.
&&
.MARINE...
FORECAST WINDS AND SEAS CONTINUE TO REMAIN ON TRACK.
A RELATIVELY QUIET PERIOD WITH SUB-SCA CONDITIONS WILL FEATURE
LATE AFT/EARLY EVE ENHANCEMENT OF THE SW FLOW FROM THE NY BIGHT
EAST ALONG THE OCEAN WATERS. THESE WINDS MAY GUSTS TO AROUND 20
KT WITH SEAS AS HIGH AS 4 FT. HIGH PRESSURE WILL THEN BUILD
ACROSS THE WATERS ON TUE WITH TRANQUIL CONDITIONS THROUGH THU.
&&
.HYDROLOGY...
NO SIGNIFICANT RAINFALL IS FORECAST THROUGH THE UPCOMING WEEK.
&&
.TIDES/COASTAL FLOODING...
WITH A RECENT FULL MOON...BRIEF MINOR INUNDATION IS POSSIBLE
DURING THE TIMES OF HIGH TIDE ACROSS THE TYPICALLY VULNERABLE
COASTAL LOCALES INTO THE START OF THE WORK WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DW
NEAR TERM...JM/DW
SHORT TERM...DW
LONG TERM...DW/24
AVIATION...MALOIT
MARINE...JM/DW/24
HYDROLOGY...DW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1232 PM CDT SUN AUG 30 2015
.UPDATE...
ISSUED AT 1050 AM CDT SUN AUG 30 2015
FOG FINALLY STARTING TO LIFT AND BREAK UP NW OF THE STALLED
FRONTAL BOUNDARY DRAPED ACROSS CENTRAL ILLINOIS THIS MORNING.
SOUTHERLY WINDS SOUTH OF THE BOUNDARY WILL RESULT IN SOME DRIFT
NORTHWARD..WITH PLENTY OF LLVL MOISTURE IN PLACE TO FILL IN THE
SKY WITH A BKN CU FIELD SHORTLY AFTER ANY CLEARING TAKES PLACE
THIS AFTERNOON. SAME CU COULD DEVELOP SOME VERTICAL EXTENT AND
TURN INTO SCT SHOWERS AND THUNDERSTORMS, PARTICULARLY SOUTH AND
EAST OF THE BOUNDARY. NO UPDATES ANTICIPATED AT THIS TIME, JUST
MINOR ADJUSTMENTS TO HOURLY TEMP TRENDS UNDER THE STRATUS/REMAINING
FOG IN THE NW.
&&
.SHORT TERM...(TODAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
08Z/3AM SURFACE ANALYSIS SHOWS A STATIONARY FRONTAL BOUNDARY
EXTENDING FROM JUST SOUTH OF CHICAGO TO NEAR KIRKSVILLE, MISSOURI.
WHILE CURRENT KILX RADAR IMAGERY INDICATES DRY CONDITIONS ACROSS THE
BOARD...A FEW SHOWERS ARE NOTED FURTHER SOUTHWEST FROM THE OZARKS
INTO THE OHIO RIVER VALLEY. MEANWHILE...LIGHT/VARIABLE WINDS AND
INCREASED LOW-LEVEL MOISTURE NEAR THE BOUNDARY HAVE LED TO THE
DEVELOPMENT OF FOG MAINLY ALONG/NORTHWEST OF A PITTSFIELD TO
BLOOMINGTON-NORMAL LINE. HRRR CONTINUES TO FOCUS MUCH OF THE
WIDESPREAD FOG ACROSS THIS AREA THROUGH MID-MORNING...SO WILL NEED
TO MONITOR VISBY TRENDS FOR A POSSIBLE DENSE FOG ADVISORY. FURTHER
EAST AND SOUTH ACROSS THE REMAINDER OF THE CWA...WILL ONLY MENTION
PATCHY FOG EARLY THIS MORNING. AFTER THE MORNING FOG
DISSIPATES...WIDELY SCATTERED SHOWERS/THUNDER WILL DEVELOP AHEAD OF
THE DECAYING FRONTAL BOUNDARY...PRIMARILY EAST OF THE ILLINOIS
RIVER. AFTERNOON HIGH TEMPERATURES WILL BE SIMILAR TO
YESTERDAY...PERHAPS A DEGREE OR TWO WARMER IN THE MIDDLE 80S.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 324 AM CDT SUN AUG 30 2015
THE EXTENDED LOOKS WARM AND DRY AS UPPER-LEVEL RIDGING DOMINATES THE
EASTERN CONUS THROUGH THE END OF THE WEEK. A SLIGHT WEAKNESS IN THE
RIDGE APPEARS TO DEVELOP ACROSS ILLINOIS INTO THE OHIO RIVER
VALLEY...POTENTIALLY TRIGGERING ISOLATED AFTERNOON/EVENING
CONVECTION TUESDAY THROUGH FRIDAY. HOWEVER...MID-LEVEL WARMING
BENEATH THE RIDGE WILL LIKELY LEAD TO CAPPING AND AN OVERALL
SUPPRESSION OF CONVECTION. AS A RESULT...WILL MAINTAIN A DRY
FORECAST WITH HIGH TEMPERATURES CLIMBING INTO THE UPPER 80S AND
LOWER 90S EACH DAY. THE NEXT SIGNIFICANT CHANCE FOR PRECIPITATION
WILL LIKELY HOLD OFF UNTIL EARLY NEXT WEEK WHEN A SHORT-WAVE TROUGH
GRADUALLY FLATTENS THE PREVAILING RIDGE AND PUSHES A COLD FRONT INTO
THE REGION. MODELS ARE NOT IN AGREEMENT CONCERNING TIMING THIS FAR
OUT...BUT TYPICAL TREND IN THIS TYPE OF SCENARIO IS USUALLY SLOWER.
AS A RESULT...WILL MAINTAIN DRY WEATHER THROUGH SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1227 PM CDT SUN AUG 30 2015
PIA IMPROVING SLOWLY AS THE FOG FROM THIS MORNING CONTINUES TO
LIFT OUT AND BURN OFF. BMI FINALLY COMING UP TO MVFR. TEMPOS FOR
MVFR AT LEAST FOR A COUPLE HOURS NW OF THE BOUNDARY, VFR THROUGH
THE EVENING/POST SUNSET. AROUND MIDNIGHT, EXPECT THE REDEVELOPMENT
OF THE FOG. HAVE STARTED THAT TREND WITHOUT DROPPING THE VIS TOO
MUCH. AREAS MAY SEE IFR TOWARDS DAWN. LIGHT AND VARIABLE
WINDS...WITH A SOUTHERLY FETCH MORE LIKELY SOUTH OF THE DECAYING
BOUNDARY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
333 PM CDT SUN AUG 30 2015
.SYNOPSIS...
ISSUED AT 314 PM CDT SUN AUG 30 2015
SURFACE RIDGE AXIS EXTENDS FROM THE GREAT LAKES THROUGH THE CWA
AND INTO THE SOUTH CENTRAL PLAINS AT MID AFTN. THE FAIRLY
WIDESPREAD DENSE FOG BURNED OFF BY MID TO LATE AM LEAVING BEHIND
FAIRLY EXTENSIVE STRATUS WHICH HAS BEEN STEADILY ERODING FROM THE
SOUTH AND EVOLVING INTO SCATTERED STRATOCU DECK. THE INCREASING
PEAKS OF SUNSHINE HAS HELPED TO BUMP TEMPS UP TO NEAR LATE
AUGUST NORMALS WITH MANY AREAS IN THE UPPER 70S TO LOWER 80S.
THE EXCEPTION BEING MAINLY PORTIONS OF NORTHEAST IA WHERE STRATUS
SILL LINGERS AND AIDING IN HOLDING TEMPS DOWN IN THE LOWER 70S
ATTIM... BUT WITH MORE LATE DAY SUNSHINE SHOULD SEE TEMPS IN THESE
AREAS SURGE LATE. PATTERN ALOFT FEATURES AN AMPLIFIED RIDGE /HEAT DOME/
THROUGH THE PLAINS IN ADVANCE OF A PACIFIC NORTHWEST TROUGH. THE NEXT
24 HOURS WILL SEE THIS RIDGE AND WARMER AIR BUILD INTO THE MID-
MISSISSIPPI VLY AS THE PACIFIC NORTHWEST TROUGH SHIFTS ACROSS THE
NORTHERN ROCKIES. THIS WILL RESULT IN CONTINUATION OF DRY CONDITIONS
WITH WARMER TEMPS ON MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 314 PM CDT SUN AUG 30 2015
MAIN CHALLENGE REMAINS LOW CLOUDS AND FOG POTENTIAL WITH IMPACT ON
TEMPS.
FOLLOWING TRENDS PER SATL AND OBS FROM LATE AFTN WITH DECREASING STRATUS
NORTHWEST CWA EVOLVING INTO SCATTERED STRATOCUMULUS THEN MOSTLY
CLEAR FOR A TIME THIS EVENING. LATE EVENING AND OVERNIGHT WITH
CONTINUED WEAK WINDS AND ABUNDANT LOW LEVEL MOISTURE EXPECT
REDEVELOPMENT OF FOG DENSE IN SOME AREAS... WITH ALSO SOME STRATUS
POSSIBLE ALTHOUGH UNCERTAIN ON EXTENT OF ANY STRATUS FORMATION WITH
LATEST RAP AND NAM MODELS SHOWING AROUND 15+ KTS OF WIND JUST ABOVE
MOIST LAYER WHICH MAY BE SUFFICIENT MIXING TO OFFSET WIDESPREAD STRATUS
FORMATION AND WITH JUST DIURNAL CUMULUS ACROSS MO DON/T EXPECT ANY
ADVECTION OF LOW DECK. MIN TEMPS WILL BE CHALLENGING AND DEPENDENT ON
FOG AND STRATUS TRENDS. AS WE SAW THIS AM... POTENTIAL FOR AREAS THAT
STAY CLEAR LONGER TO RADIATE DOWN INTO THE 50S WITH NEAR CALM WINDS.
OTHERWISE... WITH TEMPS A BIT WARMER TODAY FOR MANY AND WITH MID AFTN
DEWPTS IN MID/UPPER 60S I HAVE KEPT LOWS MAINLY IN RANGE OF 60-67 DEGS.
ON MONDAY...ANY FOG SHOULD BURN OFF A BIT EARLIER TOMORROW BY MID AM
WITH A BIT STRONGER SOUTHERLY WIND DEVELOPING OF 5-10 KTS. ANY
STRATUS SHOULD LIFT TO FAIR WX CUMULUS DURING AFTERNOON AND GENERALLY
MOSTLY SUNNY SKIES. THIS WILL ALLOW TEMPS TO CLIMB WELL INTO THE 80S
WITH WIDESPREAD MID TO A FEW UPPER 80S. THESE TEMPS COUPLED WITH
DEWPTS WELL IN THE 60S TO NEAR 70 DEGS WILL MAKE FOR VERY WARM FEEL
WITH HEAT INDICES AROUND 90/L90S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 314 PM CDT SUN AUG 30 2015
OVERVIEW...BUILDING AND PERSISTENT UPPER-LEVEL RIDGE OVER THE
CENTRAL U.S. WILL LEAD TO ABOVE AVERAGE TEMPERATURES AND HUMID
CONDITIONS THROUGH THE EXTENDED PERIOD. OVERALL CHANCES FOR RAIN
ARE VERY LOW.
TUESDAY AND WEDNESDAY...1000-500MB THICKNESS VALUES ARE FORECAST TO
BE NEAR 576-579 DAM WITH 850MB TEMPS IN THE UPPER TEENS/NEAR 20 C.
FORECAST HIGHS ARE IN THE UPPER 80S TO NEAR 90 F...WITH HEAT INDICES
IN THE LOWER TO MIDDLE 90S.
A SHORTWAVE TROUGH FROM REMNANT MONSOONAL CONVECTION MAY TRAVERSE
THE MIDWEST ON WEDNESDAY BUT MODELS TRACK IT NW OF E IOWA/W
ILLINOIS. CONSEQUENTLY KEPT THE FORECAST DRY.
THURSDAY THROUGH SATURDAY...RAW MODELS STILL APPEAR TO HAVE A WARM
BIAS AND ARE PROJECTING LOWER TO MIDDLE 90S. HUMID
CONDITIONS...850MB TEMPS IN THE UPPER TEENS TO POSSIBLY LOWER 20S
CELSIUS...AND A LOWER SEPTEMBER SUN ANGLE BACK A TEMP FORECAST
SLIGHTLY BELOW THE HIGHER RAW MODEL DATA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 116 PM CDT SUN AUG 30 2015
ANTICIPATE STRATUS TO CONTINUE LIFTING TO SCT-BKN STRATOCU DECK WITH
WIDESPREAD MVFR BASES AND CIGS BECOMING VFR BY LATE PM. GIVEN
CONTINUED WEAK LOW LEVEL FLOW AND ABUNDANT MOISTURE EXPECT MORE FOG
TO DEVELOP BY LATE EVENING AND OVERNIGHT WITH POTENTIAL FOR SOME STRATUS
WITH CONDITIONS LOWERING INTO MVFR TO IFR... WITH POCKETS OF LIFR/VLIFR.
ON MONDAY EXPECT SIMILAR TRENDS TO TODAY WITH FOG LIFTING BY AROUND
MID AM WITH ANY STRATUS LIFTING INTO VFR STRATOCU DECK DURING AFTERNOON.
LIGHT AND VARIABLE WINDS WILL TURN SOUTHERLY AT 5-10 KTS ON MONDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...UTTECH
AVIATION...MCCLURE
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1247 PM CDT SUN AUG 30 2015
.AVIATION...MDT CU EVIDENT AS LOW LEVEL MOISTURE BEGINS TO INTRUDE
ON WEAK SOUTHERLY FLOW. NOT EXPECTING MVFR CIG AT LFT TO PERSIST.
THIS FLOW WILL BRING TYPICAL LATE SUMMER PATCHY FOG TO THE PRONE
AIRPORTS LATE TNITE...MVFR/TEMPO IFR LCH AND ARA. AN UPPER TROF
SETTING UP OVER EAST TEXAS IS EXPECTED TO ENHANCE SUFFICIENT
INSTABILITY TO DELIVER SOME SCATTERED TSTMS TO THE BPT TERMINAL
AROUND THIS TIME ON MONDAY...VCTS.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 1106 AM CDT SUN AUG 30 2015/
DISCUSSION...
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO HAVE DEVELOPED OVER THE
EASTERN COASTAL WATERS ALONG A NE TO SW ORIENTED CONVERGENT
BOUNDARY. RUC APPEARS TO HAVE THE BEST HANDLE ON THIS
ACTIVITY...AND INSISTS THAT IT WILL DIMINISH BY THE AFTERNOON. NOT
QUITE SOLD ON THAT SCENARIO...SO ADDED SMALL POPS FOR THIS AREA
INTO COASTAL SOUTH CENTRAL LA FOR THE REST OF THE DAY. IN ADDITION
TO A DENSER CU FIELD...SEEING SOME HIGH CLOUDS STREAKING EAST
INTO THE REGION AHEAD OF AN UPPER TROF DIGGING INTO EAST TX.
ATMOSPHERE AS DEPICTED ON 12Z KLCH RAOB CONTINUES TO HAVE A
PRONOUNCED DRY LAYER FROM ROUGHLY 5-16K FT...WHICH SHOULD LIMIT
CONVECTION TO PERHAPS A ROGUE SHOWER OR TWO ALONG THE AFTERNOON
SEA BREEZE.
13
PREV DISCUSSION... /ISSUED 614 AM CDT SUN AUG 30 2015/
AVIATION...
A BIT OF BR THRU SUNRISE OTHERWISE VFR FLIGHT RULES EXPECTED
THROUGH THE DAY... AS WINDS SWING AROUND TO THE SE.
PREV DISCUSSION... /ISSUED 304 AM CDT SUN AUG 30 2015/
DISCUSSION...
WX MAP SHOWS WEAK SFC HIGH ACROSS THE CAROLINAS WITH WEAK RIDGING
SW ACROSS OUR REGION THIS MORNING...WITH WEAK SE FLOW ACROSS THE
COASTAL WATERS INTO SE TX. RETREATING NE OF THE REGION...ALLOWING
FOR A RETURN FLOW ACROSS THE NW GULF INTO SE TX. TEMPS A LITTLE
WARMER THIS MORNING...MAINLY IN THE UPPER 60S TO LOWER 70S. PARTLY
CLOUDY CONDITIONS EXPECTED TODAY WITH HIGHS IN THE LOWER/MID
90S...AND MINIMAL CHANCES OF RAIN...LESS THAN 10%
THE WX PATTERN OVER THE REGION WILL BE DOMINATED BY UPPER LOWS
OVER THE NORTHERN GULF THIS WEEK. THE CURRENT UPPER LOW OFF THE
FL PANHANDLE WILL CONTINUE TO LIFT NE TODAY...WITH ANOTHER SHARP
SHORTWAVE TROF EXPECTED TO CUT OFF OVER TX TODAY AND MON AND ONLY
DRIFT EAST THIS WEEK...BASICALLY PARKING OVER SE TX/LA THRU THE
END OF NEXT WEEK. THIS WILL GRADUALLY LEAD TO INCREASING POPS
ACROSS THE REGION STARTING MON WITH A SLIGHT CHANCE...WITH BETTER
CHANCES BEGINNING TUE-SAT. AT THIS TIME...DOESN`T LOOK LIKE A
COMPLETE WASHOUT ANY GIVEN DAY...BUT WILL LIKELY BE ~30-40% EACH
DAY...MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS. TEMPS
WILL CONTINUE MID 70S FOR LOWS...AND LOWER/MID 90S FOR
HIGHS...TYPICAL FOR LATE SUMMER.
DML
MARINE...
A LIGHT EAST TO SOUTHEAST FLOW WILL PREVAIL OVER THE GULF WATERS THROUGH
THE UPCOMING WEEK AS THE REGION REMAINS ON THE SOUTHWEST FLANK OF
HIGH PRESSURE CENTERED OVER THE MID ATLANTIC STATES. THE CHANCE OF
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE THIS WEEK AS AN
UPPER LEVEL TROUGH OF LOW PRESSURE DIGS INTO EAST TEXAS AND MOVES
SLOWLY EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 94 70 93 72 / 10 10 20 10
LCH 90 73 90 75 / 10 10 20 20
LFT 91 72 91 73 / 10 10 20 10
BPT 90 74 90 75 / 10 20 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...11
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1106 AM CDT SUN AUG 30 2015
.DISCUSSION...
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO HAVE DEVELOPED OVER THE
EASTERN COASTAL WATERS ALONG A NE TO SW ORIENTED CONVERGENT
BOUNDARY. RUC APPEARS TO HAVE THE BEST HANDLE ON THIS
ACTIVITY...AND INSISTS THAT IT WILL DIMINISH BY THE AFTERNOON. NOT
QUITE SOLD ON THAT SCENARIO...SO ADDED SMALL POPS FOR THIS AREA
INTO COASTAL SOUTH CENTRAL LA FOR THE REST OF THE DAY. IN ADDITION
TO A DENSER CU FIELD...SEEING SOME HIGH CLOUDS STREAKING EAST
INTO THE REGION AHEAD OF AN UPPER TROF DIGGING INTO EAST TX.
ATMOSPHERE AS DEPICTED ON 12Z KLCH RAOB CONTINUES TO HAVE A
PRONOUNCED DRY LAYER FROM ROUGHLY 5-16K FT...WHICH SHOULD LIMIT
CONVECTION TO PERHAPS A ROGUE SHOWER OR TWO ALONG THE AFTERNOON
SEA BREEZE.
13
&&
.PREV DISCUSSION... /ISSUED 614 AM CDT SUN AUG 30 2015/
AVIATION...
A BIT OF BR THRU SUNRISE OTHERWISE VFR FLIGHT RULES EXPECTED
THROUGH THE DAY... AS WINDS SWING AROUND TO THE SE.
PREV DISCUSSION... /ISSUED 304 AM CDT SUN AUG 30 2015/
DISCUSSION...
WX MAP SHOWS WEAK SFC HIGH ACROSS THE CAROLINAS WITH WEAK RIDGING
SW ACROSS OUR REGION THIS MORNING...WITH WEAK SE FLOW ACROSS THE
COASTAL WATERS INTO SE TX. RETREATING NE OF THE REGION...ALLOWING
FOR A RETURN FLOW ACROSS THE NW GULF INTO SE TX. TEMPS A LITTLE
WARMER THIS MORNING...MAINLY IN THE UPPER 60S TO LOWER 70S. PARTLY
CLOUDY CONDITIONS EXPECTED TODAY WITH HIGHS IN THE LOWER/MID
90S...AND MINIMAL CHANCES OF RAIN...LESS THAN 10%
THE WX PATTERN OVER THE REGION WILL BE DOMINATED BY UPPER LOWS
OVER THE NORTHERN GULF THIS WEEK. THE CURRENT UPPER LOW OFF THE
FL PANHANDLE WILL CONTINUE TO LIFT NE TODAY...WITH ANOTHER SHARP
SHORTWAVE TROF EXPECTED TO CUT OFF OVER TX TODAY AND MON AND ONLY
DRIFT EAST THIS WEEK...BASICALLY PARKING OVER SE TX/LA THRU THE
END OF NEXT WEEK. THIS WILL GRADUALLY LEAD TO INCREASING POPS
ACROSS THE REGION STARTING MON WITH A SLIGHT CHANCE...WITH BETTER
CHANCES BEGINNING TUE-SAT. AT THIS TIME...DOESN`T LOOK LIKE A
COMPLETE WASHOUT ANY GIVEN DAY...BUT WILL LIKELY BE ~30-40% EACH
DAY...MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS. TEMPS
WILL CONTINUE MID 70S FOR LOWS...AND LOWER/MID 90S FOR
HIGHS...TYPICAL FOR LATE SUMMER.
DML
MARINE...
A LIGHT EAST TO SOUTHEAST FLOW WILL PREVAIL OVER THE GULF WATERS THROUGH
THE UPCOMING WEEK AS THE REGION REMAINS ON THE SOUTHWEST FLANK OF
HIGH PRESSURE CENTERED OVER THE MID ATLANTIC STATES. THE CHANCE OF
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE THIS WEEK AS AN
UPPER LEVEL TROUGH OF LOW PRESSURE DIGS INTO EAST TEXAS AND MOVES
SLOWLY EAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 94 70 93 72 / 10 10 20 10
LCH 90 73 90 75 / 10 10 20 20
LFT 91 72 91 73 / 10 10 20 10
BPT 90 74 90 75 / 10 20 20 20
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
635 PM EDT SUN AUG 30 2015
.AVIATION...
SCATTERED SHOWERS, ISOLATED THUNDERSTORMS, AND WHAT REMAINS OF
DIURNAL CU WILL DIMINISH OVER THE NEXT COUPLE OF HOURS AS THE
BOUNDARY LAYER STABILIZES. DESPITE A HEALTHY COVERAGE OF MOSTLY
TRANSPARENT CIRRUS, RADIATING CONDITIONS SHOULD BE SUFFICIENTLY
FAVORABLE FOR IFR/LIFR TO DEVELOP LATE TONIGHT AS HIGH PRESSURE
SETTLES OVER THE AREA.
//DTW THRESHOLD PROBABILITIES...
* LOW FOR VSBY AOB 1/2 MILE 09-12Z.
&&
.PREV DISCUSSION...ISSUED 353 PM EDT SUN AUG 30 2015
SHORT TERM... AFTERNOON AND TONIGHT
MID AFTERNOON MESOANALYSIS INDICATES LOWEST 100 MB MLCAPE IN THE
1000-1500 J/KG RANGE FROM THE OHIO BORDER TO ABOUT THE I-96/696
CORRIDOR. THE RADAR TREND HAS BEEN RELATIVELY SOFT GIVEN THE
INSTABILITY SUGGESTING EITHER DAYTIME HEATING NEEDS A LITTLE MORE
TIME OR THAT MID LEVEL SUBSIDENCE IS SUFFICIENT TO CAP DEEP
CONVECTION. MOST RECENT RAP MODEL SOUNDINGS SUPPORT THE LATTER WITH
THE DEPICTION OF SURFACE BASED PARCELS JUST BARELY CLEARING THE
DEEPENING 700-500 MB WARM/STABLE LAYER. AT THE SAME TIME...THE
NEWEST MESOSCALE MODELS ALLOWING EXPLICIT CONVECTION PRODUCE
SCATTERED COVERAGE OF SHOWERS WITH AN ISOLATED THUNDERSTORM DURING
PEAK HEATING FROM LATE AFTERNOON THROUGH EARLY EVENING. THE MOST
PRUDENT APPROACH IS TO ALLOW FOR AN ISOLATED THUNDERSTORM
CONSIDERING A WIND HAZARD IS IN PLAY CONDITIONAL ON STORM
DEVELOPMENT. WV SATELLITE IMAGERY CONTINUES TO SUPPORT MODEL
SOUNDINGS THAT SHOW VERY DRY AIR CENTERED AROUND 500 MB. THE DRY AIR
IS SYMPTOMATIC OF THE LARGER SCALE SUBSIDENCE OCCURRING THROUGH THE
MID LEVELS THAT IS INHIBITING CONVECTION IN THE FIRST PLACE...BUT
WHICH ALSO COULD PROVIDE STRONG NEGATIVE BUOYANCY POTENTIAL SHOULD
INSTABILITY BECOME ADEQUATE FOR DEEP CONVECTION.
POINTS NORTH OF THE I-69 CORRIDOR WILL BE DRY BUT CLOUDY DURING THE
LATE AFTERNOON AND EVENING...AND ANY SHOWERS/STORMS THAT ARE ABLE TO
FORM SOUTH OF THAT LINE WILL QUICKLY DISSIPATE WITH THE LOSS OF
SURFACE HEATING BY MID EVENING. THAT WILL LEAVE A CLEARING TREND TO
OCCUR THROUGH THE OVERNIGHT AS SURFACE HIGH PRESSURE BECOMES RE-
ESTABLISHED OVER LOWER MICHIGAN. THE NORTHERN FRINGES OF THE SURFACE
HIGH REMAINS SET TO ESTABLISH AREAS OF FOG IN SE MICHIGAN TOWARD
SUNRISE AS MIN TEMPS SETTLE IN THE LOWER TO MID 60S. PROJECTED MIN
TEMPS ARE ABOUT A CATEGORY BELOW SURFACE DEWPOINT OBSERVED DURING
THE AFTERNOON TODAY WITH JUST A FEW DEGREES OF DRY ADVECTION
EXPECTED TONIGHT. THIS ADDS SOME CONFIDENCE TO FOG COVERAGE IN OUR
AREA COMBINED WITH THE WIDESPREAD OBSERVATIONAL EVIDENCE OVER
WISCONSIN/IOWA/ILLINOIS FROM THIS MORNING.
LONG TERM...MONDAY THROUGH SATURDAY
THE ANTICIPATED WAVELENGTH BROADENING OF UPPER LEVEL RIDGE IS
FORECASTED TO ACCELERATE MONDAY WITH A CENTROID OF THE UPPER LEVEL
GEOPOTENTIAL HEIGHT MAX BREAKING OFF OF THE RIDGE PEAK AND ROLLING
EASTWARD INTO MUCH OF EASTERN CANADA. MODELS FORECAST A WEAKNESS
DEVELOPING WITHIN THE RIDGE FOR THE BEGINNING OF THE WEEK
PERIOD....BUT ALL INDICATIONS ARE THE SLIGHTLY COOLER MIDLEVEL
TEMPERATURES WILL REMAIN CONFINED TO THE OHIO RIVER VALLEY. A VERY
WEAK BAROCLINIC ZONE...WITH NO JET SUPPORT ALOFT...WILL MATERIALIZE
TO SOUTH OF THE OHIO/MICHIGAN BORDER. IT IS ALONG THIS FEATURE AND
TO THE SOUTH WHERE A BETTER CHANCE EXISTS FOR A POP-UP SHOWER OR
THUNDERSTORM. FOR SOUTHEASTERN MICHIGAN THE FORECAST WILL REMAIN
DRY. WITH THE RIDGE EXPANDING EAST...THE HEAT AND UNCOMFORTABLE
CONDITIONS WILL GET STARTED WITH TEMPERATURES AND DEWPOINTS
COMBINING TO PUSH HEAT INDICES INTO THE MID TO UPPER 80S FOR MONDAY.
THE WEAK TEMPERATURE DISCONTINUITY OR FRONTAL ZONE IS THEN
FORECASTED TO LIFT SLIGHTLY NORTHWARD TUESDAY. THIS WILL OCCUR HAS
LOOSELY DEFINED AND WEAK SHORTWAVE ENERGY CONSOLIDATES INTO SOME
ORGANIZATION OVER GREATER PORTIONS OF OHIO AND INDIANA. A PLAN
VIEW OF MIDLEVEL OR 700 MB TEMPERATURES SHOWS THIS WITH SOME SUB
7C 700 MB TEMPERATURES LIFTING ACROSS THE STATELINE INTO FAR
SOUTHEASTERN MICHIGAN. IT IS A STEEP LAPSE RATE POCKET FROM
800-700MB THAT MAY THEN ALLOW FOR SOME CONVECTIVE SHOWER/TSTORM
DEVELOPMENT TUESDAY AFTERNOON AS THE BOUNDARY LIFTS NORTHWARD.
WILL REFRAIN FROM ADDING A PRECIPITATION MENTION THIS FORECAST
ISSUANCE AS POTENTIAL STILL APPEARS TO BE LESS THAN 20 PERCENT.
WORKING OFF WARMER MINS...TEMPERATURES ARE EXPECTED TO MODERATE A
FEW MORE DEGREES WITH HIGHS EASILY REACHING THE MIDDLE TO UPPER
80S TUESDAY AFTERNOON. HEAT INDICES ARE FORECASTED TO ECLIPSE THE
90 DEGREE MARK.
EXTENDED...BY THE MIDDLE OF NEXT WEEK...SOUTHEAST MICHIGAN WILL BE
FIRMLY UNDER THE UPPER LEVEL RIDGING AND SOUTHERLY FLOW. THIS WILL
BRING A CONTINUATION OF ABOVE NORMAL TEMPERATURES ALONG WITH DRY
CONDITIONS WHICH WILL PERSIST THROUGH THE REMAINDER OF THE WEEK AND
INTO THE WEEKEND.
MARINE...
VERY QUIET MARINE WEATHER WILL PERSIST ON THE GREAT LAKES THROUGH
MUCH OF THE UPCOMING WEEK. A STRONG RIDGE OF UPPER LEVEL HIGH
PRESSURE WILL MAINTAIN LIGHT FLOW AND A GENERAL SOUTHWEST WIND
DIRECTION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....JVC
SHORT TERM...BT
LONG TERM....CB/SS
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
353 PM EDT SUN AUG 30 2015
.SHORT TERM... AFTERNOON AND TONIGHT
MID AFTERNOON MESOANALYSIS INDICATES LOWEST 100 MB MLCAPE IN THE
1000-1500 J/KG RANGE FROM THE OHIO BORDER TO ABOUT THE I-96/696
CORRIDOR. THE RADAR TREND HAS BEEN RELATIVELY SOFT GIVEN THE
INSTABILITY SUGGESTING EITHER DAYTIME HEATING NEEDS A LITTLE MORE
TIME OR THAT MID LEVEL SUBSIDENCE IS SUFFICIENT TO CAP DEEP
CONVECTION. MOST RECENT RAP MODEL SOUNDINGS SUPPORT THE LATTER WITH
THE DEPICTION OF SURFACE BASED PARCELS JUST BARELY CLEARING THE
DEEPENING 700-500 MB WARM/STABLE LAYER. AT THE SAME TIME...THE
NEWEST MESOSCALE MODELS ALLOWING EXPLICIT CONVECTION PRODUCE
SCATTERED COVERAGE OF SHOWERS WITH AN ISOLATED THUNDERSTORM DURING
PEAK HEATING FROM LATE AFTERNOON THROUGH EARLY EVENING. THE MOST
PRUDENT APPROACH IS TO ALLOW FOR AN ISOLATED THUNDERSTORM
CONSIDERING A WIND HAZARD IS IN PLAY CONDITIONAL ON STORM
DEVELOPMENT. WV SATELLITE IMAGERY CONTINUES TO SUPPORT MODEL
SOUNDINGS THAT SHOW VERY DRY AIR CENTERED AROUND 500 MB. THE DRY AIR
IS SYMPTOMATIC OF THE LARGER SCALE SUBSIDENCE OCCURRING THROUGH THE
MID LEVELS THAT IS INHIBITING CONVECTION IN THE FIRST PLACE...BUT
WHICH ALSO COULD PROVIDE STRONG NEGATIVE BUOYANCY POTENTIAL SHOULD
INSTABILITY BECOME ADEQUATE FOR DEEP CONVECTION.
POINTS NORTH OF THE I-69 CORRIDOR WILL BE DRY BUT CLOUDY DURING THE
LATE AFTERNOON AND EVENING...AND ANY SHOWERS/STORMS THAT ARE ABLE TO
FORM SOUTH OF THAT LINE WILL QUICKLY DISSIPATE WITH THE LOSS OF
SURFACE HEATING BY MID EVENING. THAT WILL LEAVE A CLEARING TREND TO
OCCUR THROUGH THE OVERNIGHT AS SURFACE HIGH PRESSURE BECOMES RE-
ESTABLISHED OVER LOWER MICHIGAN. THE NORTHERN FRINGES OF THE SURFACE
HIGH REMAINS SET TO ESTABLISH AREAS OF FOG IN SE MICHIGAN TOWARD
SUNRISE AS MIN TEMPS SETTLE IN THE LOWER TO MID 60S. PROJECTED MIN
TEMPS ARE ABOUT A CATEGORY BELOW SURFACE DEWPOINT OBSERVED DURING
THE AFTERNOON TODAY WITH JUST A FEW DEGREES OF DRY ADVECTION
EXPECTED TONIGHT. THIS ADDS SOME CONFIDENCE TO FOG COVERAGE IN OUR
AREA COMBINED WITH THE WIDESPREAD OBSERVATIONAL EVIDENCE OVER
WISCONSIN/IOWA/ILLINOIS FROM THIS MORNING.
&&
.LONG TERM...MONDAY THROUGH SATURDAY
THE ANTICIPATED WAVELENGTH BROADENING OF UPPER LEVEL RIDGE IS
FORECASTED TO ACCELERATE MONDAY WITH A CENTROID OF THE UPPER LEVEL
GEOPOTENTIAL HEIGHT MAX BREAKING OFF OF THE RIDGE PEAK AND ROLLING
EASTWARD INTO MUCH OF EASTERN CANADA. MODELS FORECAST A WEAKNESS
DEVELOPING WITHIN THE RIDGE FOR THE BEGINNING OF THE WEEK
PERIOD....BUT ALL INDICATIONS ARE THE SLIGHTLY COOLER MIDLEVEL
TEMPERATURES WILL REMAIN CONFINED TO THE OHIO RIVER VALLEY. A VERY
WEAK BAROCLINIC ZONE...WITH NO JET SUPPORT ALOFT...WILL MATERIALIZE
TO SOUTH OF THE OHIO/MICHIGAN BORDER. IT IS ALONG THIS FEATURE AND
TO THE SOUTH WHERE A BETTER CHANCE EXISTS FOR A POP-UP SHOWER OR
THUNDERSTORM. FOR SOUTHEASTERN MICHIGAN THE FORECAST WILL REMAIN
DRY. WITH THE RIDGE EXPANDING EAST...THE HEAT AND UNCOMFORTABLE
CONDITIONS WILL GET STARTED WITH TEMPERATURES AND DEWPOINTS
COMBINING TO PUSH HEAT INDICES INTO THE MID TO UPPER 80S FOR MONDAY.
THE WEAK TEMPERATURE DISCONTINUITY OR FRONTAL ZONE IS THEN
FORECASTED TO LIFT SLIGHTLY NORTHWARD TUESDAY. THIS WILL OCCUR HAS
LOOSELY DEFINED AND WEAK SHORTWAVE ENERGY CONSOLIDATES INTO SOME
ORGANIZATION OVER GREATER PORTIONS OF OHIO AND INDIANA. A PLAN
VIEW OF MIDLEVEL OR 700 MB TEMPERATURES SHOWS THIS WITH SOME SUB
7C 700 MB TEMPERATURES LIFTING ACROSS THE STATELINE INTO FAR
SOUTHEASTERN MICHIGAN. IT IS A STEEP LAPSE RATE POCKET FROM
800-700MB THAT MAY THEN ALLOW FOR SOME CONVECTIVE SHOWER/TSTORM
DEVELOPMENT TUESDAY AFTERNOON AS THE BOUNDARY LIFTS NORTHWARD.
WILL REFRAIN FROM ADDING A PRECIPITATION MENTION THIS FORECAST
ISSUANCE AS POTENTIAL STILL APPEARS TO BE LESS THAN 20 PERCENT.
WORKING OFF WARMER MINS...TEMPERATURES ARE EXPECTED TO MODERATE A
FEW MORE DEGREES WITH HIGHS EASILY REACHING THE MIDDLE TO UPPER
80S TUESDAY AFTERNOON. HEAT INDICES ARE FORECASTED TO ECLIPSE THE
90 DEGREE MARK.
.EXTENDED...BY THE MIDDLE OF NEXT WEEK...SOUTHEAST MICHIGAN WILL BE
FIRMLY UNDER THE UPPER LEVEL RIDGING AND SOUTHERLY FLOW. THIS WILL
BRING A CONTINUATION OF ABOVE NORMAL TEMPERATURES ALONG WITH DRY
CONDITIONS WHICH WILL PERSIST THROUGH THE REMAINDER OF THE WEEK AND
INTO THE WEEKEND.
&&
.MARINE...
VERY QUIET MARINE WEATHER WILL PERSIST ON THE GREAT LAKES THROUGH
MUCH OF THE UPCOMING WEEK. A STRONG RIDGE OF UPPER LEVEL HIGH
PRESSURE WILL MAINTAIN LIGHT FLOW AND A GENERAL SOUTHWEST WIND
DIRECTION.
&&
.AVIATION...ISSUED 117 PM EDT SUN AUG 30 2015
STUBBORN MVFR CEILING...MOSTLY FROM PTK NORTHWARD...IS ASSOCIATED
WITH A FILLING WARM FRONT/TROUGH THAT IS MOVING SLOWLY EASTWARD
DURING THE AFTERNOON. THE DEPARTURE OF THE FRONTAL REMNANTS WILL
ALLOW LOW END VFR CEILING TO DEVELOP AT ALL LOCATIONS AS SURFACE
HEATING HELPS LIFT THE CLOUD BASE. THAT WILL LEAVE COVERAGE OF
SHOWERS OR ISOLATED THUNDERSTORMS TO BE MONITORED THROUGH MID
EVENING. EXPECTATION REMAINS THAT COVERAGE WILL BE TOO LOW TO
PINPOINT AT A TERMINAL LOCATION DEFERRING TO LATER UPDATES AS RADAR
TRENDS BECOME MORE CLEAR. DIMINISHING CLOUDS DURING THE EVENING WILL
LIKELY LEAD TO FOG AGAIN LATE TONIGHT. THERE WAS QUITE A BIT OF
IFR/LIFR COVERAGE OVER WISCONSIN/IOWA/ILLINOIS TO GUIDE POTENTIAL AS
THE NORTHERN FRINGES OF HIGH PRESSURE SETTLES OVER SE MICHIGAN
THROUGH MONDAY MORNING.
FOR DTW... LINGERING WARMTH AND HUMIDITY WILL PROMOTE LIFTING AND
PERSISTENCE OF CEILING AROUND 4500 FT THROUGH THE AFTERNOON FOLLOWED
BY A GRADUAL CLEARING TREND DURING THE EVENING. CLEAR SKY AND LIGHT
WIND WILL MAKE IFR FOG LIKELY AROUND SUNRISE MONDAY.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING 5000 FT OR LESS DURING THE AFTERNOON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...BT
LONG TERM....CB/SS
MARINE.......CB
AVIATION.....BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
117 PM EDT SUN AUG 30 2015
.AVIATION...
STUBBORN MVFR CEILING...MOSTLY FROM PTK NORTHWARD...IS ASSOCIATED
WITH A FILLING WARM FRONT/TROUGH THAT IS MOVING SLOWLY EASTWARD
DURING THE AFTERNOON. THE DEPARTURE OF THE FRONTAL REMNANTS WILL
ALLOW LOW END VFR CEILING TO DEVELOP AT ALL LOCATIONS AS SURFACE
HEATING HELPS LIFT THE CLOUD BASE. THAT WILL LEAVE COVERAGE OF
SHOWERS OR ISOLATED THUNDERSTORMS TO BE MONITORED THROUGH MID
EVENING. EXPECTATION REMAINS THAT COVERAGE WILL BE TOO LOW TO
PINPOINT AT A TERMINAL LOCATION DEFERRING TO LATER UPDATES AS RADAR
TRENDS BECOME MORE CLEAR. DIMINISHING CLOUDS DURING THE EVENING WILL
LIKELY LEAD TO FOG AGAIN LATE TONIGHT. THERE WAS QUITE A BIT OF
IFR/LIFR COVERAGE OVER WISCONSIN/IOWA/ILLINOIS TO GUIDE POTENTIAL AS
THE NORTHERN FRINGES OF HIGH PRESSURE SETTLES OVER SE MICHIGAN
THROUGH MONDAY MORNING.
FOR DTW... LINGERING WARMTH AND HUMIDITY WILL PROMOTE LIFTING AND
PERSISTENCE OF CEILING AROUND 4500 FT THROUGH THE AFTERNOON FOLLOWED
BY A GRADUAL CLEARING TREND DURING THE EVENING. CLEAR SKY AND LIGHT
WIND WILL MAKE IFR FOG LIKELY AROUND SUNRISE MONDAY.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING 5000 FT OR LESS DURING THE AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 1123 AM EDT SUN AUG 30 2015
UPDATE...
HELD THE LINE FROM THE MORNING FORECAST PACKAGE ON THUNDERSTORM
POTENTIAL FOR THIS AFTERNOON. THE SUBDUED/ISOLATED MENTION REMAINS
ON TARGET MAINLY AS DAYTIME HEATING ACTS ON LINGERING LOW LEVEL
MOISTURE. THE 12Z DTX SOUNDING INDICATES THE BEGINNING OF CAP
DEVELOPMENT UNDER INFLUENCE OF SUBSIDENCE TRAILING THE UPPER LEVEL
TROUGH AXIS AS IT EXITS LOWER MICHIGAN. THE RACE IS ALSO ON
BETWEEN SURFACE HEATING AND NEGATIVE THETA-E ADVECTION AROUND 850
MB. THIS PROCESS WILL GRADUALLY REDUCE THE DEPTH OF MOISTURE
INDICATED IN THE SOUNDING. MAINTENANCE OF ISOLATED THUNDERSTORM
COVERAGE ALONG AND SOUTH OF INTERSTATE 69 IS THEN A NOD TO CONTINUED
DEPICTION OF DEVELOPMENT IN EVEN THE MOST RECENT MESOSCALE MODEL
RUNS. THE LATEST RAP SUGGESTS SURFACE BASED CAPE RISING TO ABOUT
1200 J/KG AS LONG AS DEWPOINT CAN HOLD IN THE MID 60S. CONVECTION
MAY END UP BEING MORE OF A MODERATE DEPTH SHOWER RATHER THAN A
THUNDERSTORM ASSUMING MID LEVEL SUBSIDENCE CONTINUES TO EVOLVE. IF
CONVECTION CAN BREACH THE WARM LAYER AND REACH -20C/THUNDER THEN
SOME POTENTIAL FOR PRECIP LOADED WIND GUSTS WILL EXIST DUE TO
ENTRAINMENT OF MID TO UPPER LEVEL DRY AIR INDICATED IN THE
SOUNDING AND WV IMAGERY. OTHERWISE...JUST A LOCALLY HEAVY DOWNPOUR
EXPECTED THROUGH THE PEAK HEATING CYCLE INTO EARLY EVENING.
PREV DISCUSSION...ISSUED 302 AM EDT SUN AUG 30 2015
SHORT TERM... TODAY AND TONIGHT
MOIST AIRMASS IN PLACE OVER SOUTHEAST MICHIGAN EARLY THIS
MORNING...AS 00Z DTX SOUNDING REVEALED A 700 MB DEW PT OF 4
C...850 MB DEW PT OF 12 C...ALONG WITH A PW VALUE OF 1.6 INCHES.
SHEARED OUT SHORTWAVE/PV WILL SLOWLY BE EXITING THE CENTRAL GREAT
LAKES...BUT LAST VESTIGE OF 850-700 MB THETA-E AXIS STILL PROVE
SUFFICIENT FOR ISOLATED-SCATTERED LIGHT SHOWERS THIS MORNING BEFORE
DRIER AIR ATTEMPTS TO SLOWLY FILTER INTO SOUTHERN LOWER MICHIGAN
THROUGH THE DAY...BUT UNCERTAIN WE WILL BE ABLE TO SCOUR OUT THE LOW
LEVEL MOISTURE...AS 00Z NAM MAINTAINS HIGHER RH VALUES IN THE 925-
850 MB LAYER. WITH 500 MB TEMPS FALLING UP TO 2 C DEGREES...SURFACE
BASED INSTABILITY/CAPE IS PROGGED TO RISE TO AROUND 750 J/G...PER
00Z GFS...BUT 1000-2000 J/KG PER 00Z NAM...AS SURFACE DEW PTS REMAIN
SOLIDLY IN THE 60S. HOWEVER...700 MB TEMPS WILL BE RISING TO AROUND
9 C NORTH OF I-69...WHICH SHOULD ULTIMATELY PROVIDE A SUFFICIENT
CAP. SOUTH OF I-69 IS WHERE COOLER MID LEVELS PERSIST LONGER AND
WHERE A SLIGHT/LOW CHANCE OF SHOWERS/THUNDERSTORMS WILL BE CARRIED
FOR THE AFTERNOON HOURS. MINIMAL CONCERNS FOR SEVERE WEATHER WITH
WEAK WIND FIELDS...IF IN FACT A CELL IS EVEN ABLE TO GO UP.
BASED ON PESKY CLOUDS EXPECTED TODAY...WILL HOLD MAXES AROUND 80
DEGREES...BUT POTENTIAL FOR WARMER TEMPS IS THERE WITH 850 MB TEMPS
OF 16 C. LOW LEVEL MOISTURE/ELEVATED DEW PTS HOLDING IN THE LOWER
60S TONIGHT SHOULD SET THE STAGE FOR SOME FOG AS SKIES BECOME MAINLY
CLEAR WITH LIGHT/CALM WINDS IN PLACE.
LONG TERM...MONDAY THROUGH SATURDAY
SOUTHERN PLAINS UPPER RIDGE WILL UNDERGO STEADY DOWNSTREAM
AMPLIFICATION OVER THE NEXT 48 HOURS...IN RESPONSE TO SUBSTANTIAL
HEIGHT FALLS WORKING INTO THE WESTERN CONUS. THIS PROCESS WILL
EFFECTIVELY CENTER AN UPPER LEVEL ANTICYCLONE OVER SE MICHIGAN BY
MONDAY. A HIGH DEGREE OF STABILITY UNDER THE ATTENDANT MINIMUM IN
THETA-E AND AN ELEVATED MID LEVEL TEMPERATURE PROFILE WILL YIELD
PLENTY OF SUNSHINE...AND NO REAL OPPORTUNITY FOR CONVECTIVE
DEVELOPMENT. THE INCREASE IN THICKNESSES AND GENERALLY LIGHT
SOUTHWEST FLOW WILL PROVIDE A NOTED UPTICK IN TEMPERATURES RELATIVE
TO TODAY...WITH DAYTIME READINGS REACHING THE MID 80S.
UPPER RIDGING TO REMAIN THE PRIMARY GOVERNING FEATURE THROUGH THE
REMAINDER OF THE UPCOMING WORK WEEK. THIS WILL TRANSLATE INTO A
RELATIVELY BENIGN STRETCH OF WEATHER CONDITIONS...WITH ABOVE NORMAL
WARMTH AND LIMITED /IF ANY/ POTENTIAL FOR CONVECTION. THE RIDGE
AXIS MAY LOSE SOME DEFINITION BY MIDWEEK AS A WEAK HEIGHT FALL
CENTER DRIFTS THROUGH THE OHIO VALLEY...WITH A CORRESPONDING GRADUAL
INCREASE IN THETA-E DURING THIS TIME. PLAUSIBLE SCENARIO THAT WEAK
CVA WORKING THROUGH ALONG THE NORTH END OF THIS FEATURE PROVIDES A
LOCALIZED/BRIEF WINDOW FOR ASCENT...MEDIUM RANGE GUIDANCE STILL
CENTERING ON WEDNESDAY. LOW END POTENTIAL AT THIS STAGE GIVEN AN
OTHERWISE LACKLUSTER LOOKING FORCING/WIND FIELD.
MARINE...
BENIGN MARINE WEATHER WILL CONTINUE ACROSS THE GREAT LAKES REGION
THROUGH MUCH OF THE UPCOMING WEEK. A STRONG RIDGE OF UPPER LEVEL
HIGH PRESSURE WILL MAINTAIN LIGHT FLOW AND A GENERAL SOUTHWEST WIND
DIRECTION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
UPDATE.......BT
SHORT TERM...SF
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
404 PM CDT SUN AUG 30 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM CDT SUN AUG 30 2015
WATER VAPOR IMAGERY ALONG WITH RAP H5 HEIGHT ANALYSIS SHOWS UPPER
RIDGING BUILDING IN THIS AFTERNOON. A TROUGH EJECTING ACROSS THE
NRN ROCKIES HAS ALLOWED A BROAD AREA OF SFC LOW PRESSURE TO FORM
ACROSS ERN MT/NRN NODAK/SRN CANADA. IT IS THIS LOW THAT HAS
RESULTED IN AN INCREASING PRESSURE GRADIENT AND THE STRONGER SOUTH
WINDS WE HAVE SEEN TODAY.
IT IS THESE SOUTH WINDS THAT MAKE THE FORECAST FOR TONIGHT TRICKY.
NAM BUFR SOUNDINGS MONDAY MORNING LOOK LIKE CARBON COPIES OF THE MPX
SOUNDING THIS MORNING...WHICH OF COURSE WAS ASSOCIATED WITH ANOTHER
ROUND OF LOW STRATUS. STRATUS IS STILL HANGING TOUGH IN IOWA AND
WITH THE PATTERN TO OUR SOUTHEAST NOT MUCH DIFFERENT FROM WHAT WE
HAVE SEEN THE PAST COUPLE OF NIGHTS...EXPECT STRATUS TO EXPAND AGAIN
TONIGHT...THE QUESTION IS JUST HOW FAR NW DOES IT COME. ONE BIG
DIFFERENCE BETWEEN TODAY AND THE PAST COUPLE OF DAYS IS WE HAVE
STRONGER WINDS AND BETTER BOUNDARY LAYER MIXING TODAY. THE GRADIENT
AND ASSOCIATED WINDS WILL REMAIN IN PLACE THROUGH THE NIGHT...ADDING
A LAYER OF UNCERTAINTY TO THE SKY FORECAST. FOR NOW...DID A SOFT
PLAY FOR THE STRATUS...WITH 40/50% COVERAGE FROM SOUTH CENTRAL MN
INTO EAST CENTRAL MN AND WRN WI LATE TONIGHT/EARLY MONDAY MORNING
AND WILL LET FUTURE SHIFTS UP SKY COVER IF NEED BE WHEN THERE IS A
BETTER HANDLE ON WHERE IT IS GOING.
FOR MONDAY...THE PREVIOUSLY MENTIONED LOW WELL SEND A FRONT ACROSS
THE DAKOTAS...APPROACHING WEST CENTRAL MN BY THE AFTERNOON.
HOWEVER...WE ARE NOT ANTICIPATING ANY ACTIVITY ALONG THE FRONT THIS
FAR SOUTH...SO WE REMOVED WHAT SMALL POPS WERE MENTION MONDAY
AFTERNOON IN OUR NW. BESIDE NONE OF THE HI-RES...DETERMINISTIC...OR
ENSEMBLE MODELS SHOWING ANY PRECIP IN OUR AREA...FORECAST SOUNDINGS
AT AXN AND SURROUNDING SITES SHOW A STRONG WARM NOSE BETWEEN H8 AND
H7 THAT LOOKS TO KEEP A LID ON DEEP MOIST CONVECTION THIS FAR SOUTH.
IN ADDITION...THE WAVE AND ASSOCIATED HEIGHT FALLS DRIVING THIS
FRONT ARE GOING FROM MT TO HUDSON BAY...STAYING WELL NW OF THE
MPX AREA...SO FEEL CONFIDENT IN THE DRY FORECAST FOR MONDAY.
BESIDE DRY...ALL OF THE MODELS SHOW 925-850 TEMPS IN WRN MN DROPPING
A COUPLE OF DEGS C MONDAY AFTERNOON COMPARED TO WHAT WE ARE SEEING
TODAY...SO EXPECT HIGHS TO BE NO WARMER THAN WHAT WE ARE SEEING
TODAY AND LIKELY A COUPLE OF DEGREES COOLER IN WRN MN.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM CDT SUN AUG 30 2015
NO BIG CHANGES TO THE LONG TERM FORECAST AS THE PATTERN STILL
FAVORS RIDGING IN THE CENTRAL CONUS AND ABOVE NORMAL TEMPERATURES
LASTING INTO LABOR DAY WEEKEND.
THE LONGWAVE RIDGE AXIS WILL CONTINUE TO SHIFT EAST ON
TUESDAY...BUT THE BIGGEST RESERVOIR OF WARMTH WILL LINGER FROM THE
FOUR CORNERS UP THROUGH THE NORTHERN PLAINS. THE NAEFS
STANDARDIZED 850MB TEMPERATURE ANOMALIES ARE COMMONLY BETWEEN TWO
AND THREE SIGMA OVER THE NEXT WEEK IN THESE AREAS. AS THE 500MB
RIDGE AXIS SLIDES EAST ON TUESDAY THE LONGWAVE PATTERN LOSES SOME
OF ITS AMPLITUDE AND THE 850MB TEMPERATURE ADVECTION DECREASES
BEFORE REACHING THE FORECAST AREA. AS A RESULT...THE FORECAST AREA
WILL MAINTAIN MID 80S FOR HIGHS AS WE HEAD TOWARD MID WEEK...BUT
THE TEMPERATES WILL NOT APPROACH THE MID /AND EVEN UPPER/ 90S
THAT ARE CURRENTLY BEING OBSERVED IN THE DAKOTAS THIS AFTERNOON.
WESTERN MN IS ALREADY SEEING DEWPOINTS IN THE UPPER 60S AND
EASTERN MN AND WESTERN WI WILL SOON FOLLOW...THESE DEWPOINTS WILL
LINGER THROUGH THE WEEK AND THE DEWPOINT WILL MOST LIKELY HIT 70
DEGREES IN MANY LOCATIONS THIS WEEK. IN THE WED-THU TIME
FRAME...MUCH OF THE 12Z GUIDANCE HINTS AT THE CHANCE FOR RAIN WITH
MOISTURE TRANSPORT EMBEDDED IN THE LOW LEVEL SOUTHWEST FLOW. THE
FORCING ISNT EXTREMELY...BUT THERE IS ELEVATED INSTABILITY AND
THE CAP ISNT OVERLY STRONG EITHER WITH THE 12-14C AIR AT 700MB
REMAINING WEST OF THE AREA IN THE DAKOTAS. THEREFORE...WE
MAINTAINED THE SMALL POPS IN THE FORECAST...BUT ADMITTEDLY THERE
IS LOW CONFIDENCE ON TIMING/AMOUNTS AND EVEN IF THERE WILL BE MUCH
CONVECTIVE INITIATION LOCALLY.
THE PERSISTENT TROUGH OVER THE GULF OF ALASKA AND PACIFIC
NORTHWEST FINALLY LOOKS TO MAKE SOME EASTERN PROGRESS AS WE HEAD
TOWARD THE BACK HALF OF LABOR DAY WEEKEND. THE OPERATIONAL
GUIDANCE AND ENSEMBLE OUTPUT HAS SLIGHTLY SLOWED THE ARRIVAL OF
THE COLD FRONT...BUT AT THE VERY LEAST WE CAN SAY NEXT WEEKEND
LOOKS MORE UNSETTLED WITH A PATTERN SHIFT LOCALLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1251 PM CDT SUN AUG 30 2015
STRONGER WINDS AND ASSOCIATED MECHANICAL MIXING HELPED CLEAN
STRATUS OUT MUCH FASTER THIS MORNING THAN WHAT WE SAW YESTERDAY.
REALLY...THE ONLY QUESTION THIS TAF PERIOD IS WHERE DOES THE
STRATUS RETURN TONIGHT. FORECAST SOUNDINGS FROM THE NAM LOOK LIKE
CARBON COPIES OF THIS MORNINGS SOUNDING HERE AT MPX...SO STRATUS
IS LOOKING LIKE A REAL POSSIBILITY FOR A THIRD NIGHT IN A ROW. ONE
BIG DIFFERENCE THOUGH BETWEEN TODAY AND YESTERDAY AS WE HAVE
STRONGER WINDS TODAY...WHICH MEANS BETTER BOUNDARY LAYER MIXING.
THIS IS WHAT ADDS UNCERTAINTY TO THE STRATUS FORECAST FOR
TONIGHT...IS THIS MIXING ENOUGH TO KEEP THE STRATUS FARTHER EAST
TONIGHT. FOR NOW...PLAYED UP THE STRATUS THREAT AT WIS TERMINALS
WHERE WINDS ARE WEAKEST TODAY...BUT IT IS CERTAINLY POSSIBLE TO
SEE STRATUS AS FAR WEST AS MSP/STC AGAIN TONIGHT.
KMSP...WILL BE VFR WITH SOUTH WINDS THE REST OF THE DAY. CURRENT
THINKING IS BETTER MIXING TODAY WILL MAKE IT MORE DIFFICULT TO GET
THE STRATUS GOING TONIGHT...BUT IF YOU WERE TO GO STRAIGHT OFF THE
NAM BUFR SOUNDING...MSP WILL SEE A REPEAT PERFORMANCE ON THE
STRATUS FOR A THIRD NIGHT IN A ROW. DECIDED TO GO THE SCT008 ROUTE
FOR NOW UNTIL THERE IS MORE CONFIDENCE ON WHERE STRATUS WILL END
UP TONIGHT.
/OUTLOOK FOR KMSP/
TUE-THU...VFR WINDS S 5-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS BILLINGS MT
311 PM MDT SUN AUG 30 2015
.SHORT TERM...VALID FOR MON AND TUE...
A SEASONABLY STRONG COLD FRONT WILL CROSS THE REGION TONIGHT AND
LEAD INTO A PERIOD OF QUIET WEATHER MONDAY AND TUESDAY.
TONIGHT...THE 12 UTC MODELS AND MORE CONTEMPORARY HRRR MODEL RUNS
ARE IN GENERAL AGREEMENT IN SHOWING THE COLD FRONT MOVING THROUGH
THE LIVINGSTON AREA BETWEEN 6 PM AND 9 PM MDT...BILLINGS BETWEEN 7
PM AND 11 MDT...SHERIDAN BETWEEN 11 PM AND 3 AM MDT...AND MILES
CITY AND BAKER AFTER MIDNIGHT. WE EXPECT A SHIFT TO WEST-NORTHWEST
WINDS BEHIND THE FRONT WITH GUSTS TO 45 MPH BASED ON THE DEGREE OF
LOW- AND MID-LEVEL COLD AIR ADVECTION AND THERMAL GRADIENT IN THE
FRONTAL ZONE. THAT/S SUPPORTED BY MOS STATISTICAL OUTPUT /THE MAV
AND MET/ AS WELL. FORECAST SOUNDINGS DO SUGGEST THE BOUNDARY LAYER
MAY BE A BIT TOO DECOUPLED FOR FULL MOMENTUM TRANSFER OF THE 40 KT
WINDS THAT ARE SIMULATED WITHIN 3000 FT AGL OF THE GROUND...BUT WE
BELIEVE THE COLD AIR ADVECTION WILL OVERCOME THAT TENDENCY. A RED
FLAG WARNING CONTINUES THROUGH THE EVENING TO CONVEY THE RISK THIS
COLD FRONTAL PASSAGE WILL PRESENT FOLLOWING LATE-AFTERNOON MIX-OUT
OF GUSTY SOUTHWEST WINDS AND DRYING IN SOUTH CENTRAL MT.
WHERE PRECIPITATION IS CONCERNED...ISOLATED SHOWERS AND STORMS ARE
POSSIBLE WITH THE SHORTWAVE TROUGH PASSAGE DRIVING THE COLD FRONT
EASTWARD...MAINLY THIS EVENING. STRONG MID-LEVEL WINDS SUGGEST A
STRONG STORM IS POSSIBLE...BUT WE FEEL THAT RISK WILL GENERALLY BE
MITIGATED BY A LACK OF STRONGER INSTABILITY.
MONDAY...THE POST-FRONTAL AIR MASS WILL BE COOLER...DRIER...AND
STABLE. HIGHS WILL BE NEAR 80 F WITH AFTERNOON HUMIDITIES AROUND
20 PERCENT PER THE 12 UTC MULTI-MODEL CONSENSUS WE USED TO DERIVE
THE OFFICIAL FORECAST...BUT WIND/S WILL NOT BE ANYTHING TO WRITE
HOME ABOUT.
TUESDAY...DEEPER MIXING TO 700 MB OR MORE AND WARMING TEMPERATURES
ALOFT WITH SOUTHWEST FLOW WILL PROMOTE A WARM-UP INTO THE UPPER
80S AND LOWER 90S F. ATMOSPHERIC MOISTURE CONTENT WON/T CHANGE
TOO MUCH AND THE RESULT WILL BE EVEN LOWER HUMIDITIES WELL DOWN
INTO THE TEENS...THOUGH WINDS AREN/T EXPECTED TO BE STRONG ENOUGH
FOR ANY RED-FLAG-TYPE CONDITIONS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
UPPER TROUGH OVER THE PACIFIC NORTHWEST WILL MOVE INLAND ON
WEDNESDAY AND THIS SETS UP DEEP SOUTHWEST FLOW OVER SOUTHERN
MONTANA AND NORTHERN WYOMING. HIGHS WILL APPROACH 90 DEGREES ON
WEDNESDAY AHEAD OF COLD FRONT. THIS FRONT WILL MOVE THROUGH
WEDNESDAY NIGHT AND BRING COOLER WEATHER FOR THE END OF THE WEEK.
IN FACT...THIS WILL MARK A DRAMATIC PATTERN CHANGE AS THE WESTERN
TROUGH SWINGS OVER THE NORTHERN ROCKIES THIS WEEKEND. THIS WILL
END THE WARM AND DRY REGIME AND PROVIDE COOLER TEMPERATURES AND A
CHANCE OF PRECIPITATION. SOME OF THE MOUNTAIN TOPS COULD EVEN SEE
A LITTLE SNOW SATURDAY AND SUNDAY...ALTHOUGH THE STRONGER FORCING
AND MOST LIKELY PRECIPITATION PLACEMENT...WOULD BE OVER NORTHERN
MONTANA. TWH
&&
.AVIATION...
STRONG SOUTHWEST WINDS WILL CONTINUE AT KLVM THIS AFTERNOON WITH
SOME GUSTS TO 35KTS. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
WILL DEVELOP THROUGH THIS EVENING AS A COLD FRONT APPROACHES. SOME
OF THE STORMS NORTHWEST OF BILLINGS COULD BE STRONG WITH WIND
GUSTS TO 45KTS. A COLD FRONT WILL MOVE THROUGH CENTRAL LOCATIONS
FROM KBIL TO KLVM FROM 01-03Z...KSHR 02-04Z AND KMLS AND KBHK
04-06Z. NORTHWEST WINDS WILL GUST TO 35KTS BEHIND THE FRONT. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 054/082 054/089 059/090 055/075 048/069 047/070 045/071
20/U 00/U 01/U 11/B 23/T 33/T 22/T
LVM 045/080 046/086 051/085 048/072 041/067 038/069 039/073
20/K 00/K 01/B 23/T 44/T 44/T 32/T
HDN 054/083 053/092 057/094 056/080 048/075 048/072 046/073
20/U 00/U 11/U 11/B 22/T 22/T 22/T
MLS 057/082 055/092 059/097 059/081 051/077 049/073 047/072
30/U 00/U 00/U 11/B 22/T 22/T 22/T
4BQ 056/080 055/092 059/096 058/082 053/079 051/071 049/070
30/U 00/U 00/U 01/U 12/T 22/T 22/T
BHK 055/079 054/091 057/095 058/081 051/080 049/073 046/070
30/U 00/U 10/U 11/U 12/T 22/T 22/T
SHR 050/083 049/091 054/092 053/082 046/076 044/070 042/071
20/U 00/U 10/U 01/B 12/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONES 28-29-34-35-39>42-56-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
954 AM PDT SUN AUG 30 2015
.SYNOPSIS...A BROAD LOW PRESSURE TROUGH MOVING INTO THE GREAT BASIN
AND MOJAVE DESERT REGION WILL BRING DRY SOUTHWEST FLOW WITH COOLER
AND BREEZY CONDITIONS THROUGH THE COMING WEEK AND INTO THE LABOR DAY
WEEKEND. SLIGHT CHANCES FOR THUNDERSTORMS WILL REMAIN IN EASTERN
MOHAVE COUNTY WITH ACTIVITY DECREASING THROUGH TUESDAY.
&&
.UPDATE...A BAND OF MID AND HIGH CLOUDS EXTENDING FROM SOUTHERN
CALIFORNIA ACROSS SOUTHERN NEVADA INTO UTAH WAS SHOWING SIGNS OF
DECREASING AND LIFTING TO THE NORTHEAST. THE LATEST HIGH LEVEL RH
FORECASTS INDICATE THIS TREND WHICH ALLOW MORE SUNSHINE DURING THE
AFTERNOON. THE 12Z LAS VEGAS SOUNDING REVEALED 2-3 DEGREES C OF
COOLING BETWEEN THE SURFACE AND 700 MB AND HIGH TEMPS THIS AFTERNOON
WILL REFLECT THE BEGINNING OF THIS COOLING TREND. OVERALL...THE
FORECAST TRENDS LOOK OKAY AND NO IMMEDIATE CHANGES NEEDED. -ADAIR-
&&
.PREV DISCUSSION...
200 AM PDT SUN AUG 30 2015
.SHORT TERM...TONIGHT THROUGH TUESDAY.
A SOUTHWESTERLY FLOW HAS TAKEN HOLD OF THE REGION IN RESPONSE TO
TROUGHING ACROSS THE PACIFIC NORTHWEST AND HIGH PRESSURE SHUNTED
SOUTHWARD INTO NORTHERN MEXICO. THIS HAS RESULTED IN THE MOIST
MONSOONAL FLOW BEING SUBDUED AND PUSHED MORE INTO ARIZONA LEAVING
MOST OF OUR FORECAST AREA HIGH AND DRY FOR THE FORESEEABLE FUTURE.
ONLY CAVEAT TO THAT WILL BE ACROSS EASTERN MOHAVE COUNTY THE NEXT
COUPLE AFTERNOONS WHERE SOME MARGINAL INSTABILITY WILL REMAIN IN
PLACE TO SUPPORT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY THE
HIGHER TERRAIN. EARLY MORNING RUNS OF THE HRRR SUPPORT THIS AGAIN
FOR THIS AFTERNOON...PARTICULARLY NORTH OF THE I-40 CORRIDOR IN
EASTERN MOHAVE COUNTY...AND HAVE MAINTAINED POPS FOR THOSE AREAS
THIS AFTERNOON.
ELSEWHERE...SOME PERIODS OF HIGH CLOUDS CAN BE EXPECTED BUT NOTHING
OVERLY SUBSTANTIAL. HIGH TEMPERATURES WILL CREEP DOWNWARD THROUGH
TUESDAY BUT SHOULD REMAIN SLIGHTLY ABOVE NORMAL THROUGH
MONDAY...BEFORE RETURNING TO NEAR NORMAL ON TUESDAY.
.LONG TERM...WEDNESDAY THROUGH SUNDAY.
NUMEROUS SHORTWAVES WILL MOVE THROUGH A LONGWAVE TROUGH WHICH WILL
REMAIN OVER THE PAC NW/NRN ROCKIES DURING MUCH OF THE PERIOD. THIS
WILL KEEP THE SOUTHERN GREAT BASIN/MOJAVE DESERT UNDER A SOUTHWEST
FLOW. LOOK FOR BREEZY TO LOCALLY WINDY AFTERNOON/EVENING HOURS WITH
SLIGHTLY BELOW NORMAL TEMPERATURES.
SOMETHING TO MONITOR WILL BE THE POTENTIAL DEVELOPMENT OF A TROPICAL
SYSTEM IN THE EASTERN PACIFIC. BOTH THE GFS/ECMWF DEVELOP A SYSTEM
WELL SOUTHWEST OF CABO SAN LUCAS WEDNESDAY. THE FEATURE MOVES NORTH
BUT LOOKS TO GET SHEARED APART WEST OF THE BAJA PENINSULA FRIDAY
WITH REMNANT MID LEVEL ENERGY GETTING CAUGHT IN THE SOUTHWEST FLOW
AND MOVING OVER ARIZONA SATURDAY. THE ASSOCIATED MOISTURE BEARS
WATCHING AS SOME OF IT MAY GET PULLED NORTHWARD UP THE COLORADO
RIVER AND INTO WESTERN ARIZONA SATURDAY NIGHT OR SUNDAY.
&&
.AVIATION...FOR MCCARRAN...FAIR WEATHER EXPECTED TODAY WITH PERIODS
OF PASSING HIGH CLOUDS. SOUTHWESTERLY WINDS EXPECTED MOST OF THE DAY
WITH SPEEDS OF 12-20 KTS WITH GUSTS TO 25 KTS. WHILE
UNLIKELY...THERE IS A SMALL POSSIBILITY OF A PERIOD OF SOUTHEAST
WINDS BETWEEN 15Z-18Z. WIND GUSTS WILL DECREASE AFTER SUNSET.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...FAIR WEATHER EXPECTED WITH ONLY SLIGHT CHANCES FOR
THUNDERSTORMS IN FAR EASTERN MOHAVE COUNTY. ELSEWHERE..JUST PASSING
HIGH CLOUDS EXPECTED WITH AREAS OF SMOKE IN THE OWENS VALLEY AND
NEAR KBIH. BREEZY SOUTHWEST WINDS OF 15-20KT WITH GUSTS TO 30KTS
EXPECTED IN THE AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION WILL NOT BE
NECESSARY. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY
SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
SHORT TERM/AVIATION...OUTLER
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 NORMAN OK
220 PM CDT SUN AUG 30 2015
.DISCUSSION...
MAINLY DRY WEATHER AND NEAR OR SLIGHTLY ABOVE AVERAGE TEMPERATURES
ARE EXPECTED DURING THE NEXT SEVEN DAYS.
THROUGH 10 PM THIS EVENING...A FEW THUNDERSTORMS MAY FORM NEAR A
WEAK SURFACE FRONT OVER SOUTHERN OKLAHOMA...NEAR WAURIKA TO
COALGATE. CAPPING IS RATHER STRONG...HOWEVER A MID LEVEL
WEAKNESS CENTERED OVER EASTERN OKLAHOMA MAY BE ENOUGH FOR TO
ALLOW FOR ISOLATED DEVELOPMENT. THUS...WENT WITH A 20 PERCENT
CHANCE IN THESE LOCATIONS. IF STORMS FORM...THEY WOULD BE SLOW
MOVERS...PRODUCE LOCALIZED DOWNPOURS...AND GUSTY WINDS PERHAPS UP
TO 50 TO 60 MPH. ANY CONVECTION WOULD DIMINISH WITH THE LOSS OF
DAYTIME HEATING.
AFTER 10 PM THIS EVENING INTO MONDAY MORNING...PATCHY FOG MAY FORM
AGAIN ACROSS MAINLY NORTHERN OKLAHOMA. LATEST HRRR RUNS HAVE BEEN
CONSISTENT WITH DEPICTING LOW CLOUDS AND FOG OVER NEAR ALVA...
ENID...AND CHEROKEE. THIS SEEMS REASONABLE AS HIGHER SURFACE
DEWPOINTS ARE FORECAST TO MOVE INTO THESE LOCATIONS LATE TONIGHT.
THUS...ADDED MENTION OF PATCHY FOG. DOUBT FOG WILL BE TOO DENSE
OR WIDESPREAD SINCE NO RAIN WILL OCCUR IN THESE LOCATIONS TODAY.
MONDAY WILL BE MOSTLY SUNNY AND HOTTER WITH INCREASING SOUTH
SURFACE WINDS. CANNOT COMPLETELY RULE OUT A STRAY AFTERNOON OR
EVENING STORM IN SOUTHEAST OF A WAURIKA TO ADA LINE WHERE MID
LEVEL TEMPERATURES WILL BE A BIT COOLER AND CAPPING IS A BIT
WEAKER...BUT WILL NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
MONDAY NIGHT THROUGH NEXT SUNDAY...SEASONABLY HOT AND MAINLY DRY
WEATHER WILL CONTINUE WITH A WEAK MID/UPPER RIDGE OVERHEAD. LOW
STORM CHANCES MAY RETURN TO MAINLY NORTHWESTERN OKLAHOMA BY THE
WEEKEND...BUT CONFIDENCE IS LOW.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 66 93 70 92 / 0 0 0 0
HOBART OK 65 97 71 96 / 0 0 0 0
WICHITA FALLS TX 69 97 72 97 / 0 0 0 0
GAGE OK 62 96 69 95 / 0 0 0 0
PONCA CITY OK 66 93 70 93 / 0 0 0 0
DURANT OK 71 95 71 94 / 20 10 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
1226 PM CDT SUN AUG 30 2015
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
VFR CONDITIONS ARE GENERALLY EXPECTED. SURFACE WINDS SHOULD STAY
BELOW 10 KT AT ALL LOCATIONS THROUGH 14Z MONDAY BEFORE INCREASING.
PATCHES OF MVFR OR LOWER CONDITIONS WITH BR MAY OCCUR 07-15Z
MAINLY OVER NORTHERN OKLAHOMA...BUT DID NOT MENTION IN TAFS DUE
LOW CONFIDENCE OF OCCURRENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 1113 AM CDT SUN AUG 30 2015/
DISCUSSION...
THE UPDATE THIS MORNING IS MAINLY TO REMOVE MENTION OF FOG AND
MORNING THUNDER. FOG HAS CLEARED ALL OF THE OBSERVATION SITES. IF
THERE IS SOME LINGERING FOG OVER ALFALFA/GRANT COUNTIES... DO NOT
EXPECT IT TO REMAIN LONG AND CONDITIONS WILL CONTINUE TO IMPROVE.
TO THE SOUTH... ONE ISOLATED SHOWER IS DRIFTING ACROSS BRYAN
COUNTY... BUT OTHERWISE HAVE SEEN NO SIGNIFICANT DEVELOPMENT. WILL
KEEP THE MENTION OF ISOLATED SHOWER FOR THE MORNING HOURS BUT
REDUCE POPS TO LESS THAN 20. STILL SOME MIXED SIGNALS FOR
REDEVELOPMENT THIS AFTERNOON IN THE SOUTHEAST AND WILL LEAVE THE
LOW AFTERNOON POPS IN THE SOUTHEAST.
PREV DISCUSSION... /ISSUED 646 AM CDT SUN AUG 30 2015/
DISCUSSION...
30/12Z TAF ISSUANCE.
AVIATION...
LIFR CONDITIONS IN FOG/STRATUS ARE EXPECTED ACROSS NORTHERN
OKLAHOMA TERMINALS THROUGH 15Z. WILL ALSO MENTION MVFR FOG OVER
CENTRAL OKLAHOMA TERMINALS OF KOKC/KOUN FIRST FEW HOURS OF
FORECAST. OTHERWISE VFR FORECAST WITH LIGHT NORTHERLY WINDS
BECOMING LIGHT SOUTHERLY LATE IN THE AFTERNOON AND TONIGHT.
PREV DISCUSSION... /ISSUED 406 AM CDT SUN AUG 30 2015/
DISCUSSION...
MAIN ADJUSTMENT TO GOING FORECAST PACKAGE WAS TO ADD FOG FOR THIS
MORNING ACROSS AREAS NORTH OF I-40. THE MOST WIDESPREAD AND
POSSIBLY DENSE FOG WILL BE OVER FAR NORTH/NORTHWEST OKLAHOMA
NEAREST LOW LEVEL RIDGE AXIS. CONFIDENT THAT THERE WILL BE FOG BUT
JUST NOT SURE HOW WIDESPREAD ANY DENSE FOG WILL BE. THE MOST
AGGRESSIVE MODELS...WRF AND HRRR KEEP A MAJORITY OF DENSE FOG UP
IN KANSAS THROUGH 9 AM. DENSE FOG ADVISORY NOT ANTICIPATED AT THIS
POINT BUT WE WILL WATCH TRENDS AND ISSUE AS NEEDED. POPS WERE ALSO
CONTINUED THROUGH TODAY ACROSS SOUTHEAST CWA NEAR MID-LEVEL SHEAR
AXIS AND EFFECTIVE SYNOPTIC BOUNDARY.
TODAYS TEMPS WERE COOLED A BIT FROM PREVIOUS FORECAST AS WELL.
INITIALIZATIONS CAME IN A FEW DEGREES COOLER MAINLY OVER NORTHERN
AND WESTERN OKLAHOMA...AND WITH PLUME OF HIGH LEVEL SMOKE THIS
SOUNDS REASONABLE. GFS AND ECM HAVE TRENDED WEAKER WITH THE UPPER
LEVEL RIDGE AND HAVE GENERALLY UNDERFORECAST STRENGTH/PERSISTENCE
OF LONGWAVE TROUGH AXIS JUST TO OUR EAST. THIS WILL YIELD SLIGHTLY
COOLER TEMPS THROUGH THE WEEK MOST AREAS AND ALTHOUGH POPS ARE TOO
LOW TO MENTION...CANNOT RULE OUT AN ISOLATED SHOWER OR WEAK STORM
ESPECIALLY FAR NORTHWEST OKLAHOMA CLOSER TO POSSIBLE HIGH PLAINS
REMNANTS AND FAR SOUTHEAST OKLAHOMA CLOSER TO UPPER TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 68 93 70 92 / 0 0 0 0
HOBART OK 67 97 71 95 / 0 0 0 0
WICHITA FALLS TX 71 97 72 96 / 0 0 0 0
GAGE OK 63 96 69 94 / 0 0 0 0
PONCA CITY OK 67 93 70 93 / 0 0 0 0
DURANT OK 71 95 71 94 / 10 10 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
1113 AM CDT SUN AUG 30 2015
.DISCUSSION...
THE UPDATE THIS MORNING IS MAINLY TO REMOVE MENTION OF FOG AND
MORNING THUNDER. FOG HAS CLEARED ALL OF THE OBSERVATION SITES. IF
THERE IS SOME LINGERING FOG OVER ALFALFA/GRANT COUNTIES... DO NOT
EXPECT IT TO REMAIN LONG AND CONDITIONS WILL CONTINUE TO IMPROVE.
TO THE SOUTH... ONE ISOLATED SHOWER IS DRIFTING ACROSS BRYAN
COUNTY... BUT OTHERWISE HAVE SEEN NO SIGNIFICANT DEVELOPMENT. WILL
KEEP THE MENTION OF ISOLATED SHOWER FOR THE MORNING HOURS BUT
REDUCE POPS TO LESS THAN 20. STILL SOME MIXED SIGNALS FOR
REDEVELOPMENT THIS AFTERNOON IN THE SOUTHEAST AND WILL LEAVE THE
LOW AFTERNOON POPS IN THE SOUTHEAST.
&&
.PREV DISCUSSION... /ISSUED 646 AM CDT SUN AUG 30 2015/
DISCUSSION...
30/12Z TAF ISSUANCE.
AVIATION...
LIFR CONDITIONS IN FOG/STRATUS ARE EXPECTED ACROSS NORTHERN
OKLAHOMA TERMINALS THROUGH 15Z. WILL ALSO MENTION MVFR FOG OVER
CENTRAL OKLAHOMA TERMINALS OF KOKC/KOUN FIRST FEW HOURS OF
FORECAST. OTHERWISE VFR FORECAST WITH LIGHT NORTHERLY WINDS
BECOMING LIGHT SOUTHERLY LATE IN THE AFTERNOON AND TONIGHT.
PREV DISCUSSION... /ISSUED 406 AM CDT SUN AUG 30 2015/
DISCUSSION...
MAIN ADJUSTMENT TO GOING FORECAST PACKAGE WAS TO ADD FOG FOR THIS
MORNING ACROSS AREAS NORTH OF I-40. THE MOST WIDESPREAD AND
POSSIBLY DENSE FOG WILL BE OVER FAR NORTH/NORTHWEST OKLAHOMA
NEAREST LOW LEVEL RIDGE AXIS. CONFIDENT THAT THERE WILL BE FOG BUT
JUST NOT SURE HOW WIDESPREAD ANY DENSE FOG WILL BE. THE MOST
AGGRESSIVE MODELS...WRF AND HRRR KEEP A MAJORITY OF DENSE FOG UP
IN KANSAS THROUGH 9 AM. DENSE FOG ADVISORY NOT ANTICIPATED AT THIS
POINT BUT WE WILL WATCH TRENDS AND ISSUE AS NEEDED. POPS WERE ALSO
CONTINUED THROUGH TODAY ACROSS SOUTHEAST CWA NEAR MID-LEVEL SHEAR
AXIS AND EFFECTIVE SYNOPTIC BOUNDARY.
TODAYS TEMPS WERE COOLED A BIT FROM PREVIOUS FORECAST AS WELL.
INITIALIZATIONS CAME IN A FEW DEGREES COOLER MAINLY OVER NORTHERN
AND WESTERN OKLAHOMA...AND WITH PLUME OF HIGH LEVEL SMOKE THIS
SOUNDS REASONABLE. GFS AND ECM HAVE TRENDED WEAKER WITH THE UPPER
LEVEL RIDGE AND HAVE GENERALLY UNDERFORECAST STRENGTH/PERSISTENCE
OF LONGWAVE TROUGH AXIS JUST TO OUR EAST. THIS WILL YIELD SLIGHTLY
COOLER TEMPS THROUGH THE WEEK MOST AREAS AND ALTHOUGH POPS ARE TOO
LOW TO MENTION...CANNOT RULE OUT AN ISOLATED SHOWER OR WEAK STORM
ESPECIALLY FAR NORTHWEST OKLAHOMA CLOSER TO POSSIBLE HIGH PLAINS
REMNANTS AND FAR SOUTHEAST OKLAHOMA CLOSER TO UPPER TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 93 70 / 10 0 0 0
HOBART OK 92 67 97 71 / 0 0 0 0
WICHITA FALLS TX 96 71 97 72 / 10 0 0 0
GAGE OK 91 63 96 69 / 0 0 0 0
PONCA CITY OK 88 67 93 70 / 0 0 0 0
DURANT OK 94 71 95 71 / 10 10 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
135 PM EDT SUN AUG 30 2015
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL LIFT NORTH ALONG
THE APPALACHIAN CHAIN THIS AFTERNOON INTO EARLY MONDAY...BRINGING
A GREATER CHANCE FOR SHOWERS TO THE REGION. UPPER LEVEL HIGH
PRESSURE WILL THEN STRENGTHEN AND KEEP US IN A RATHER STAGNANT
PATTERN...MAINTAINING A CHANCE FOR AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EDT SUNDAY...
RADAR HAS SHOWN A SLOW INCREASE IN LIGHT REFLECTIVITY OVER THE
PAST COUPLE HOURS. THE VAST MAJORITY OF THE MOISTURE IS NOT
REACHING THE SURFACE...HOWEVER KEEPING CHANCE POPS IN EARLY THIS
AFTERNOON FOR THE OCCASIONAL SPRINKLE OR BRIEF LIGHT SHOWER ACROSS
THE MOUNTAINS. HRRR AND RAP CONTINUE TO SHOW SPOTTY PRECIPITATION
LATER THIS AFTERNOON MAINLY ACROSS THE MOUNTAINS...HOWEVER
CONTINUING WITH THE TREND OF JUST CHANCE POPS. BUMPED UP HIGH
TEMPS A BIT OUT EAST WHERE THEY HAVE HAD SOME DECENT CLEARING AND
MORE SUNSHINE.
AS OF 915 AM EDT SUNDAY...
ONLY MINOR ADJUSTMENTS TO THE NEAR TERM FORECAST. AN AREA OF
SPRINKLES/LIGHT RAIN MOVED ACROSS NW NC WITH LIGHT DRIZZLE
REPORTED AT TNB AND UKF AROUND 13Z. UPPER AIR SOUNDING AT 12Z
SHOWS THE COLUMN BEGINNING TO MOISTEN UP...HOWEVER THE LOW LEVELS
ARE STILL FAIRLY DRY SO ANY PRECIPITATION OUT OF THIS MORNINGS MID
DECK WILL BE CONFINED TO JUST A FEW SPRINKLES. ALL OTHER FORECAST
DETAILS REMAIN ON TRACK.
AS OF 715 AM EDT SUNDAY...
RADAR INDICATING LIGHT RETURNS ACROSS NORTH CAROLINA APPROACHING
OUR AREA THIS MORNING. VERY LITTLE OF THIS IS REACHING THE
GROUND...HOWEVER RAISED RAIN CHANCES SLIGHTLY DURING THE MORNING
TO ACCOUNT FOR ANY INCREASES IN THE COVERAGE OF SHOWER ACTIVITY.
OTHERWISE...THE EARLY MORNING FORECAST REMAINS ON TRACK.
AS OF 345 AM EDT SUNDAY...
STARTING THE MORNING OFF WITH A BROAD BUT WEAK UPPER LEVEL TROUGH
SITUATED FROM THE GREAT LAKES SOUTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY...WHILE SUBTROPICAL RIDGING REMAINS PARKED OFF THE ATLANTIC
COAST OF THE SOUTHEAST STATES. THIS PATTERN IS MAKING FOR
SOUTHWESTERLY WINDFLOW ALOFT FOR THE MID ATLANTIC...WHICH WILL CARRY
A SERIES OF WEAK DISTURBANCE NORTHWARD ALONG THE APPALACHIAN CHAIN.
FOR TODAY...EXPECT THE MID AND HIGH CLOUDS CURRENTLY IN PLACE TO
LINGER THROUGH THE DAY...ALTHOUGH BRIEF BREAKS WILL OCCUR AT TIMES.
SOUTH SOUTHEASTERLY WINDS NEAR THE SURFACE WILL CONTINUE TO DRAW
MOISTURE INTO THE MOUNTAINS...AND EXPECT WE WILL SEE SHOWERS DEVELOP
DURING EARLY AFTERNOON ALONG THE RIDGES. THE MID AND HIGH CLOUDS
WILL KEEP INSTABILITY QUITE LIMITED...SO DO NOT REALLY MORE THAN
VERY ISOLATED AND BRIEF THUNDERSTORMS TO DEVELOP. AFTERNOON
TEMPERATURES WILL RANGE FROM THE MID 70S TO AROUND 80 ACROSS THE
MOUNTAINS...AND REACH INTO THE LOW/MID 80S ACROSS THE PIEDMONT.
SLIGHTLY BETTER CHANCES FOR SHOWER ACTIVITY ARE EXPECTED HEADING
INTO LATE SUNDAY EVENING AS A STRONGER UPPER LEVEL DISTURBANCE
APPROACHES FROM THE SOUTH. EVEN THEN...WEATHER FORECAST MODELS ARE
CALLING FOR THE BRUNT OF RAINFALL TO MISS OUR AREA TO THE
SOUTHEAST...AND BELIEVE THE PASSAGE OF THIS SYSTEM WILL AMOUNT TO
SPOTTY SHOWERS FOR THE MOUNTAINS...AND PERHAPS THE PIEDMONT SOUTH OF
HIGHWAY 460. SUNDAY NIGHT LOWS WILL RANGE FROM THE UPPER 50S AND LOW
60S WEST...TO THE MID 60S EAST.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
A WEAK UPPER LOW AND ASSOCIATED TROPICAL MOISTURE ASSOCIATED WITH
FORMER TROPICAL SYSTEMS DANNY AND ERIKA...WILL BE LIFTING NORTHEAST
ACROSS THE REGION MONDAY ON THE WESTERN PERIPHERY OF A BUILDING
SUBTROPICAL RIDGE ACROSS THE WESTERN ATLANTIC. MODEST LOW-LEVEL
MOISTURE INCREASE IS INDICATED WITH PRECIPITABLE WATER VALUES
CREEPING INTO THE 1.5/1.6 RANGE ACROSS MUCH OF THE CWA. AT THE SAME
TIME...HOWEVER...THE UPPER TROUGH IS WEAKENING AND SHEARING OUT. ON
THE OTHER END OF THE CWA A DIFFUSE AND STALLING FRONT BOUNDARY WILL
BE LOCATED JUST TO OUR NORTH WITH THE ASSOCIATED UPPER AIR SUPPORT
HAVING LIFTED WELL NORTHEAST OF THIS REGION. DESPITE THESE WEAK
SYSTEMS...THE UNDERLYING THEME WILL BE A BROAD SUBTROPICAL RIDGE
BUILDING ACROSS MUCH OF THE EASTERN 2/3RDS OF THE U.S.
SUFFICIENT MOISTURE...INSTABILITY...AND DYNAMICS...GIVEN THE
FRONT TO THE NORTH AND UPPER TROUGH LIFTING ACROSS THE REGION...
SHOULD BE PRESENT MONDAY TO SUPPORT ISOLATED TO SCATTERED DIURNAL
CONVECTION...WITH A FEW SPRINKLES OR LIGHT SHOWERS EVEN POSSIBLE
DURING THE MORNING...TYPICAL FOR A POCKET OF REMNANT TROPICAL
MOISTURE DRIFTING ACROSS THE REGION. AM NOT CONCERNED ABOUT A HEAVY
RAIN THREAT GIVEN THE LACK OF ANY FOCUSING MECHANISM AND NOTING THAT
THE PLUME OF DEEP TROPICAL MOISTURE REMAINS GENERALLY OFF THE EAST
COAST. MODEL QPF IS VERY LACKLUSTER...GENERALLY 1/4 INCH AMOUNTS AT
BEST. THIS AGREES WELL WITH WPC.
FOR TUE-WED...THE MAIN STORY WILL BE THE BUILDING UPPER RIDGE. ANY
VESTIGE OF THE TROPICAL SYSTEMS...FRONTAL BOUNDARY...AND UPPER
TROUGH IS COMPLETELY GONE IN THIS TIME FRAME WITH 588DM OR GREATER
HEIGHTS ENCOMPASSING MOST OF THE U.S. SOUTH OF THE CANADIAN
BORDER...WEST TO THE ROCKIES. A VERY WEAK UPPER LOW TROUGH
WILL LINGER ACROSS THE WESTERN TN VALLEY INTO THE SOUTHERN
PLAINS. LINGERING TRAPPED TROPICAL MOISTURE AND DIFFERENTIAL HEATING
ACROSS THE MOUNTAINS WILL LIKELY BE SUFFICIENT EACH AFTERNOON TO
TRIGGER ISOLATED CONVECTION...BUT LITTLE TO SUPPORT MORE THAN 30
POPS AT THIS TIME. BY WED AFTERNOON...THE GFS AND ECMWF BOTH DEPICT
A POTENTIAL BACKDOOR FRONT SLIPPING INTO THE REGION FROM THE
NORTHEAST...WITH A SLIGHT INCREASE IN CONVECTION POSSIBLE ACROSS THE
NORTHERN AREAS AS A RESULT.
TEMPERATURES WILL BE ON THE INCREASE THROUGH THE PERIOD AS 850MB
TEMPS RISE FROM THE CURRENT LEVELS AROUND +14C TO +16C TOWARD +20C
DURING THE PERIOD. THIS WILL SUPPORT HIGHER MAX TEMPS...WITH SOME
AREAS ACROSS THE PIEDMONT APPROACHING 90 DEGREES...WITH 75 TO 80
MOUNTAINS AND 80S ELSEWHERE. MIN TEMPS WILL ALSO BE ON THE INCREASE
WITH HIGHER DEWPOINTS/RH/PWATS IN PLACE THROUGH THE PERIOD. OVERALL
MIN TEMPS WILL AVERAGE 10 DEGREES ABOVE NORMAL THROUGH THE PERIOD
WITH MAX TEMPS ABOUT 5 DEGREES ABOVE AVERAGE.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 415 AM EDT SUNDAY...
THE EXTENDED PERIODS CONTINUE TO BE LARGELY DOMINATED BY A BROAD
LATE SUMMER UPPER RIDGE ACROSS THE EASTERN HALF OF THE U.S.
INCREASING TROUGHING ALONG THE WEST COAST WILL ALLOW THE UPPER RIDGE
TO PUSH FURTHER EAST...QUICKLY ERASING ANY MIDWEEK EFFECTS OF A
BACKDOOR FRONT AND WEAK SHORTWAVE TRAVERSING THE NORTHEASTERN
PERIPHERY OF THE UPPER RIDGE. TROPICAL MOISTURE WILL LINGER ACROSS
THE REGION WITH NO CHANGE IN AIR MASS EXPECTED. ON THE OTHER
HAND...THERE IS SIMPLY NO SYNOPTIC/DYNAMIC TRIGGERING MECHANISM.
THIS LEAVES CONVECTION TO BE DRIVEN ENTIRELY BY DIFFERENTIAL DIURNAL
HEATING THROUGH THE END OF THE WORK WEEK.
TEMPERATURES ARE EXPECTED TO CONTINUE ABOVE NORMAL THROUGH THE
PERIOD WITH HIGHS 75 TO 80 MOUNTAINS AND 80S ELSEWHERE...NEAR 90
ACROSS THE PIEDMONT. MIN TEMPS WILL BE MORE SIGNIFICANTLY ABOVE
NORMAL WITH MAINLY 60S TO NEAR 70 PIEDMONT. THESE READINGS ARE 5 TO
10 DEGREES ABOVE NORMAL.
LOOKING AHEAD...SOME MODELS ARE ADVERTISING PERHAPS THE FIRST FALL
COLD FRONT INTO THE FOLLOWING WEEK...BUT ENTIRELY TOO FAR OUT TO
PUT ANY CREDIBILITY IN AT THIS POINT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 130 PM EDT SUNDAY...
WILL GO WITH A LIGHT WIND VFR FORECAST THROUGH THE PERIOD AT ALL
SITES...BUT WITH SOME CAVEATS. DIURNAL SHOWERS ARE DEVELOPING
AHEAD OF INCREASING MOISTURE AND A SHORT WAVE APPROACHING FROM THE
SOUTH. LOW LEVEL DRY AIR IS SLOW TO SATURATE DESPITE GOOD
TRANSPORT OF TROPICAL MOISTURE ALOFT FROM THE GULF OF MEXICO. THE
RESULT IS ABUNDANT MID/UPPER CLOUDS... SPOTTY SHOWERS/SPRINKLES...
AND NO SUB VFR CIGS. BELIEVE THIS WILL CONTINUE TO BE THE CASE
INTO EARLY THIS EVENING AS DIURNAL ACTIVITY STARTS TO WANE WITH
THE LOSS OF HEATING SO WILL GO WITH VFR CONDITIONS AND VCSH
THROUGH THE FIRST PART OF THE TAFS.
HOWEVER...THE APPROACHING WAVE LOOKS TO BRING ANOTHER CHANCE OF SHOWERS
IN FOR THE OVERNIGHT. MODELS ARE QUITE DIFFERENT IN HANDLING PRECIPITATION
POTENTIAL AND ADVECTION OF LOW LEVEL MOISTURE SO DO NOT HAVE A LOT OF
CONFIDENCE IN SPECIFIC LOCATION/TIMING OF ANY SHOWERS AND LOWER CIGS.
THUS...WILL INDICATE A GRADUAL THICKENING/LOWERING OF VFR CLOUDS AND
LEAVE OUT MENTION OF PRECIPITATION FOR NOW. WILL USE VCSH ONLY AT KDAN
SINCE THEY WILL BE CLOSEST TO ADVANCING MOISTURE AND INTRODUCE SOME
LOWER VFR CIGS FOR KBLF/KBCB/KDAN LATE TONIGHT. BELIEVE THICKENING/LOWERING
CLOUDS WILL PREVENT FOG FORMATION SO WILL HEDGE AGAINST MOST GUIDANCE
AND NOT INCLUDE ANY FOG AT KBCB OR KLWB. THERE WILL BE MORE DIURNAL
SHOWERS AND POSSIBLY SUB VFR CIGS ON MONDAY BUT MOST LIKELY BEYOND
THIS TAF PERIOD.
EXTENDED AVIATION DISCUSSION... THE FORECAST AREA WILL REMAIN IN A
WEAKLY FORCED SYNOPTIC ENVIRONMENT THROUGH MIDWEEK...WITH CHANCES FOR
DIURNAL CONVECTION MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR
FOG/STRATUS DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB.
&&
.EQUIPMENT...
AS OF 700 AM EDT SUNDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...CF/NF
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...MBS/NF
EQUIPMENT...JR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1243 PM EDT SUN AUG 30 2015
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL LIFT NORTH ALONG
THE APPALACHIAN CHAIN THIS AFTERNOON INTO EARLY MONDAY...BRINGING
A GREATER CHANCE FOR SHOWERS TO THE REGION. UPPER LEVEL HIGH
PRESSURE WILL THEN STRENGTHEN AND KEEP US IN A RATHER STAGNANT
PATTERN...MAINTAINING A CHANCE FOR AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EDT SUNDAY...
RADAR HAS SHOWN A SLOW INCREASE IN LIGHT REFLECTIVITY OVER THE
PAST COUPLE HOURS. THE VAST MAJORITY OF THE MOISTURE IS NOT
REACHING THE SURFACE...HOWEVER KEEPING CHANCE POPS IN EARLY THIS
AFTERNOON FOR THE OCCASIONAL SPRINKLE OR BRIEF LIGHT SHOWER ACROSS
THE MOUNTAINS. HRRR AND RAP CONTINUE TO SHOW SPOTTY PRECIPITATION
LATER THIS AFTERNOON MAINLY ACROSS THE MOUNTAINS...HOWEVER
CONTINUING WITH THE TREND OF JUST CHANCE POPS. BUMPED UP HIGH
TEMPS A BIT OUT EAST WHERE THEY HAVE HAD SOME DECENT CLEARING AND
MORE SUNSHINE.
AS OF 915 AM EDT SUNDAY...
ONLY MINOR ADJUSTMENTS TO THE NEAR TERM FORECAST. AN AREA OF
SPRINKLES/LIGHT RAIN MOVED ACROSS NW NC WITH LIGHT DRIZZLE
REPORTED AT TNB AND UKF AROUND 13Z. UPPER AIR SOUNDING AT 12Z
SHOWS THE COLUMN BEGINNING TO MOISTEN UP...HOWEVER THE LOW LEVELS
ARE STILL FAIRLY DRY SO ANY PRECIPITATION OUT OF THIS MORNINGS MID
DECK WILL BE CONFINED TO JUST A FEW SPRINKLES. ALL OTHER FORECAST
DETAILS REMAIN ON TRACK.
AS OF 715 AM EDT SUNDAY...
RADAR INDICATING LIGHT RETURNS ACROSS NORTH CAROLINA APPROACHING
OUR AREA THIS MORNING. VERY LITTLE OF THIS IS REACHING THE
GROUND...HOWEVER RAISED RAIN CHANCES SLIGHTLY DURING THE MORNING
TO ACCOUNT FOR ANY INCREASES IN THE COVERAGE OF SHOWER ACTIVITY.
OTHERWISE...THE EARLY MORNING FORECAST REMAINS ON TRACK.
AS OF 345 AM EDT SUNDAY...
STARTING THE MORNING OFF WITH A BROAD BUT WEAK UPPER LEVEL TROUGH
SITUATED FROM THE GREAT LAKES SOUTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY...WHILE SUBTROPICAL RIDGING REMAINS PARKED OFF THE ATLANTIC
COAST OF THE SOUTHEAST STATES. THIS PATTERN IS MAKING FOR
SOUTHWESTERLY WINDFLOW ALOFT FOR THE MID ATLANTIC...WHICH WILL CARRY
A SERIES OF WEAK DISTURBANCE NORTHWARD ALONG THE APPALACHIAN CHAIN.
FOR TODAY...EXPECT THE MID AND HIGH CLOUDS CURRENTLY IN PLACE TO
LINGER THROUGH THE DAY...ALTHOUGH BRIEF BREAKS WILL OCCUR AT TIMES.
SOUTH SOUTHEASTERLY WINDS NEAR THE SURFACE WILL CONTINUE TO DRAW
MOISTURE INTO THE MOUNTAINS...AND EXPECT WE WILL SEE SHOWERS DEVELOP
DURING EARLY AFTERNOON ALONG THE RIDGES. THE MID AND HIGH CLOUDS
WILL KEEP INSTABILITY QUITE LIMITED...SO DO NOT REALLY MORE THAN
VERY ISOLATED AND BRIEF THUNDERSTORMS TO DEVELOP. AFTERNOON
TEMPERATURES WILL RANGE FROM THE MID 70S TO AROUND 80 ACROSS THE
MOUNTAINS...AND REACH INTO THE LOW/MID 80S ACROSS THE PIEDMONT.
SLIGHTLY BETTER CHANCES FOR SHOWER ACTIVITY ARE EXPECTED HEADING
INTO LATE SUNDAY EVENING AS A STRONGER UPPER LEVEL DISTURBANCE
APPROACHES FROM THE SOUTH. EVEN THEN...WEATHER FORECAST MODELS ARE
CALLING FOR THE BRUNT OF RAINFALL TO MISS OUR AREA TO THE
SOUTHEAST...AND BELIEVE THE PASSAGE OF THIS SYSTEM WILL AMOUNT TO
SPOTTY SHOWERS FOR THE MOUNTAINS...AND PERHAPS THE PIEDMONT SOUTH OF
HIGHWAY 460. SUNDAY NIGHT LOWS WILL RANGE FROM THE UPPER 50S AND LOW
60S WEST...TO THE MID 60S EAST.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
A WEAK UPPER LOW AND ASSOCIATED TROPICAL MOISTURE ASSOCIATED WITH
FORMER TROPICAL SYSTEMS DANNY AND ERIKA...WILL BE LIFTING NORTHEAST
ACROSS THE REGION MONDAY ON THE WESTERN PERIPHERY OF A BUILDING
SUBTROPICAL RIDGE ACROSS THE WESTERN ATLANTIC. MODEST LOW-LEVEL
MOISTURE INCREASE IS INDICATED WITH PRECIPITABLE WATER VALUES
CREEPING INTO THE 1.5/1.6 RANGE ACROSS MUCH OF THE CWA. AT THE SAME
TIME...HOWEVER...THE UPPER TROUGH IS WEAKENING AND SHEARING OUT. ON
THE OTHER END OF THE CWA A DIFFUSE AND STALLING FRONT BOUNDARY WILL
BE LOCATED JUST TO OUR NORTH WITH THE ASSOCIATED UPPER AIR SUPPORT
HAVING LIFTED WELL NORTHEAST OF THIS REGION. DESPITE THESE WEAK
SYSTEMS...THE UNDERLYING THEME WILL BE A BROAD SUBTROPICAL RIDGE
BUILDING ACROSS MUCH OF THE EASTERN 2/3RDS OF THE U.S.
SUFFICIENT MOISTURE...INSTABILITY...AND DYNAMICS...GIVEN THE
FRONT TO THE NORTH AND UPPER TROUGH LIFTING ACROSS THE REGION...
SHOULD BE PRESENT MONDAY TO SUPPORT ISOLATED TO SCATTERED DIURNAL
CONVECTION...WITH A FEW SPRINKLES OR LIGHT SHOWERS EVEN POSSIBLE
DURING THE MORNING...TYPICAL FOR A POCKET OF REMNANT TROPICAL
MOISTURE DRIFTING ACROSS THE REGION. AM NOT CONCERNED ABOUT A HEAVY
RAIN THREAT GIVEN THE LACK OF ANY FOCUSING MECHANISM AND NOTING THAT
THE PLUME OF DEEP TROPICAL MOISTURE REMAINS GENERALLY OFF THE EAST
COAST. MODEL QPF IS VERY LACKLUSTER...GENERALLY 1/4 INCH AMOUNTS AT
BEST. THIS AGREES WELL WITH WPC.
FOR TUE-WED...THE MAIN STORY WILL BE THE BUILDING UPPER RIDGE. ANY
VESTIGE OF THE TROPICAL SYSTEMS...FRONTAL BOUNDARY...AND UPPER
TROUGH IS COMPLETELY GONE IN THIS TIME FRAME WITH 588DM OR GREATER
HEIGHTS ENCOMPASSING MOST OF THE U.S. SOUTH OF THE CANADIAN
BORDER...WEST TO THE ROCKIES. A VERY WEAK UPPER LOW TROUGH
WILL LINGER ACROSS THE WESTERN TN VALLEY INTO THE SOUTHERN
PLAINS. LINGERING TRAPPED TROPICAL MOISTURE AND DIFFERENTIAL HEATING
ACROSS THE MOUNTAINS WILL LIKELY BE SUFFICIENT EACH AFTERNOON TO
TRIGGER ISOLATED CONVECTION...BUT LITTLE TO SUPPORT MORE THAN 30
POPS AT THIS TIME. BY WED AFTERNOON...THE GFS AND ECMWF BOTH DEPICT
A POTENTIAL BACKDOOR FRONT SLIPPING INTO THE REGION FROM THE
NORTHEAST...WITH A SLIGHT INCREASE IN CONVECTION POSSIBLE ACROSS THE
NORTHERN AREAS AS A RESULT.
TEMPERATURES WILL BE ON THE INCREASE THROUGH THE PERIOD AS 850MB
TEMPS RISE FROM THE CURRENT LEVELS AROUND +14C TO +16C TOWARD +20C
DURING THE PERIOD. THIS WILL SUPPORT HIGHER MAX TEMPS...WITH SOME
AREAS ACROSS THE PIEDMONT APPROACHING 90 DEGREES...WITH 75 TO 80
MOUNTAINS AND 80S ELSEWHERE. MIN TEMPS WILL ALSO BE ON THE INCREASE
WITH HIGHER DEWPOINTS/RH/PWATS IN PLACE THROUGH THE PERIOD. OVERALL
MIN TEMPS WILL AVERAGE 10 DEGREES ABOVE NORMAL THROUGH THE PERIOD
WITH MAX TEMPS ABOUT 5 DEGREES ABOVE AVERAGE.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 415 AM EDT SUNDAY...
THE EXTENDED PERIODS CONTINUE TO BE LARGELY DOMINATED BY A BROAD
LATE SUMMER UPPER RIDGE ACROSS THE EASTERN HALF OF THE U.S.
INCREASING TROUGHING ALONG THE WEST COAST WILL ALLOW THE UPPER RIDGE
TO PUSH FURTHER EAST...QUICKLY ERASING ANY MIDWEEK EFFECTS OF A
BACKDOOR FRONT AND WEAK SHORTWAVE TRAVERSING THE NORTHEASTERN
PERIPHERY OF THE UPPER RIDGE. TROPICAL MOISTURE WILL LINGER ACROSS
THE REGION WITH NO CHANGE IN AIR MASS EXPECTED. ON THE OTHER
HAND...THERE IS SIMPLY NO SYNOPTIC/DYNAMIC TRIGGERING MECHANISM.
THIS LEAVES CONVECTION TO BE DRIVEN ENTIRELY BY DIFFERENTIAL DIURNAL
HEATING THROUGH THE END OF THE WORK WEEK.
TEMPERATURES ARE EXPECTED TO CONTINUE ABOVE NORMAL THROUGH THE
PERIOD WITH HIGHS 75 TO 80 MOUNTAINS AND 80S ELSEWHERE...NEAR 90
ACROSS THE PIEDMONT. MIN TEMPS WILL BE MORE SIGNIFICANTLY ABOVE
NORMAL WITH MAINLY 60S TO NEAR 70 PIEDMONT. THESE READINGS ARE 5 TO
10 DEGREES ABOVE NORMAL.
LOOKING AHEAD...SOME MODELS ARE ADVERTISING PERHAPS THE FIRST FALL
COLD FRONT INTO THE FOLLOWING WEEK...BUT ENTIRELY TOO FAR OUT TO
PUT ANY CREDIBILITY IN AT THIS POINT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 745 AM EDT SUNDAY...
CLOUD COVER CONTINUES TO THICKEN AND GRADUALLY LOWER THIS MORNING
AS WEAK UPPER LEVEL DISTURBANCES APPROACH FROM THE SOUTH. CEILINGS
ARE VFR...RANGING IN HEIGHT FROM 8KFT TO 15KFT MOST LOCATIONS.
STILL A LITTLE PATCHY FOG REPORTED IN A FEW SPOTS...HOWEVER
EXPECT VISIBILITIES TO IMPROVE AFTER 14Z WITH DAYTIME HEATING.
FOR TODAY...EXPECT A GRADUAL INCREASE IN SHOWER ACTIVITY AS WEAK
DISTURBANCES PASS ACROSS THE AREA. WEATHER MODEL FORECAST
SOUNDINGS CONTINUE TO INDICATE THAT THE LOW LEVELS OF THE
ATMOSPHERE WILL REMAIN DRY...SUCH THAT CEILING BASES WILL FALL
INTO THE 4KFT TO 8KFT RANGE DURING LATE AFTERNOON...BUT WILL
REMAIN MOSTLY VFR. ANY REDUCTIONS IN VISIBILITIES WILL BE LIMITED
TO THOSE IN RAINFALL...WHICH SHOULD BE BRIEF DUE TO THE RATHER
SPOTTY NATURE OF THE SHOWER ACTIVITY. INSTABILITY APPEARS TO BE
VERY LIMITED...SO ANY THUNDERSTORMS WHICH DEVELOP SHOULD BE
ISOLATED AND SHORT LIVED.
A STRONGER UPPER LEVEL DISTURBANCE WILL APPROACH THE AREA LATE
SUNDAY EVENING...HOWEVER WEATHER MODELS APPEAR TO BE IN GOOD
AGREEMENT THAT THE MOST SIGNIFICANT RAINFALL WILL MISS THE AREA TO
THE SOUTHEAST. AS SUCH...EXPECT CONTINUED SPOTTY RAINFALL
OVERNIGHT...WITH MAINLY VFR CEILINGS. CLOUD COVER IS EXPECTED TO
KEEP REDEVELOPMENT OF FOG MINIMAL.
EXTENDED AVIATION DISCUSSION...
THE FORECAST AREA WILL THEN REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH MIDWEEK...WITH CHANCES FOR DIURNAL CONVECTION
MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR FOG/STRATUS
DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB.
&&
.EQUIPMENT...
AS OF 700 AM EDT SUNDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...NF
NEAR TERM...CF/NF
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...NF/WP
EQUIPMENT...