Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/14/18
Area Forecast Discussion
National Weather Service La Crosse WI
538 PM CST Thu Dec 13 2018
.SHORT TERM...(This evening through Friday)
Issued at 230 PM CST Thu Dec 13 2018
Short term forecast appears to be on track with split flow pattern
bringing two main areas of precipitation toward the region. In
addition, afternoon analysis showed some returns off the KMPX radar
in western Wisconsin and southern Minnesota (likely associated with
some isentropic lift), but surface observations were not recording
any precipitation. Will need to continue to monitor trends here, as
RAP soundings have shown the potential for freezing drizzle, mainly
in southeast Minnesota, but run to run consistency on depth of the
saturated layer has not been good, so have kept the forecast dry for
Meanwhile, some light snow and/or flurries were falling across
northeast into central Minnesota along a cold front and ahead of a
trough moving into the area. The strongest forcing with this trough
still looks to stay mainly north of the forecast area, with only
perhaps some light snow sneaking into Taylor County.
To the south, a closed low over Texas had ejected some energy
northeastward, producing some precipitation across southern
Missouri. This is expected to expand farther northeast and possibly
get into far south/southeastern portions of the forecast area by
early evening, though latest trends in most CAMs keep everything
south and east of the area. For now, keeping slight chance of rain
mention in a small sliver of southern Grant county.
The next forecast challenge is then clouds/fog overnight into Friday
morning. Most models in pretty good agreement of clouds clearing out
as the cold front slides through the area this evening. However,
model soundings show a shallow layer of moisture under a pretty
stout inversion overnight. In addition, CAMs/SREF have pretty good
agreement of fog across most/all of the forecast area. May need
another Dense Fog Advisory at some point. Also, like Wednesday
night, temperatures will be below freezing, so there could be some
slick spots on roadways once again.
.LONG TERM...(Friday night through Thursday)
Issued at 230 PM CST Thu Dec 13 2018
Still looking like a fairly quiet and dry long term forecast period.
Ridging will build in for the weekend and bring slightly warmer
temperatures to the area, with highs in the mid 30s to lower 40s. A
trough axis will then slide through by Sunday afternoon, though the
associated low and precipitation look to stay well north of the
area. Northwest flow will take over in the wake of the trough,
leading to a brief cool down back into the upper 20s to lower 30s
for Monday. Still good model agreement of some shortwave energy in
the region on Tuesday, but trends have been farther north with any
precipitation, thus keeping the forecast area dry.
Then a more vigorous wave looks to dig southeast out of Canada
Wednesday afternoon into Thursday. Models differ in how much the
wave amplifies, and thus where a surface low spins up/deepens. The
13.12Z GFS is much less amplified than the 13.00Z ECMWF and keeps
the surface low and any associated precipitation north and east of
the forecast area. The 13.00Z ECMWF instead deepens the surface low
over or just east of the forecast area and brings precipitation
chances to areas east of the Mississippi River.
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 538 PM CST Thu Dec 13 2018
Last batch of lower clouds is making very slow eastward progress
at the moment, and will hang around for much of the night, likely
to be increasingly replaced by the development of fog later
tonight. MVFR ceilings at LSE will lower to IFR and current VLIFR
conditions for RST aren`t going to go much of anywhere overnight.
Looking quite likely that RST will see dense fog develop late this
evening or just after midnight, sticking around through 14-15Z
before lifting, while LSE may well also get in on the act with a
more brief period of dense fog either side of sunrise. Will of
course have to watch trends through the night to refine the
details, but many spots should see some fog before sunrise. The
good news is that once fog lifts in the 14-16Z time frame, clear
skies should make a welcome return for all areas into the
afternoon and early evening, as winds shift around to the
southwest 10-15 knots at RST, lower for LSE of course.
AREA FORECAST DISCUSSION
National Weather Service Binghamton NY
944 PM EST Thu Dec 13 2018
A moist easterly flow tonight will allow patchy drizzle and
freezing drizzle to develop over northeast Pennsylvania and the
western Catskills. A better defined weather system will impact
the region this weekend with periods of rain or showers Friday
night through Sunday, especially from the southern tier of New
York down into northeastern Pennsylvania. Then, turning much
colder with snow showers around Monday and Tuesday.
.NEAR TERM /THROUGH FRIDAY/...
With the mid evening update some minor adjustments were made
based on radar trends and regional observations. Our forecast
continues to be on track with the main uncertainty being the
presence of Freezing drizzle and fog later on tonight south and
east of Binghamton. Moisture continues to look lacking in the
snow growth zone which is supportive of freezing drizzle.
However, the development of precipitation is more of a question
given both the HRRR and RAP are not picking up on it while the
operational models do have it. Several observations are also
reporting fog northeast PA as well, coverage of this may
increase over the next few hours given the lowest levels are
saturated along with light winds. Potential is also present for
the patchy fog to cause slick spots. Will continue with an SPS
320 PM Update...Some low level instability is combining with a
weakening wave of low pressure to bring a line of snow showers
to the eastern third of the forecast area late this afternoon.
This will exit east by early evening, leaving behind some light
coatings. Current late afternoon temperatures remain locked in
the mid 20s to around 30 from roughly Interstate 81 east...with
32-40 west of Interstate 81. Expect very little change in
temperatures through the late evening hours, then perhaps a
slow rise late at night.
Overnight, a moist easterly flow in the low levels of the
atmosphere will upslope and lift to form areas of drizzle,
freezing drizzle and perhaps fog over the higher terrain of the
Poconos and western Catskills. Model soundings continue to show
the same signal, of saturated air in the lowest 3-5k ft agl of
the atmosphere, but then no moisture to form ice crystals in the
mid and upper levels. Confidence is still too low on exactly
where this freezing drizzle may set up to issue an advisory at
this time. Will cover with an SPS and continue to mention in the
HWO. Future shifts may decide a short fused winter weather
advisory is necessary, if and when reports of freezing drizzle
are actually received. Areas from Binghamton north and west
should be generally dry overnight, under mostly cloudy skies,
with a south wind 6-12 mph.
Friday: Lingering patchy drizzle, fog and pockets of freezing
drizzle southeast of I-88 in the Catskills and across much of NE
PA during the morning hours. The rest of the area will remain
mostly cloudy or overcast through the day. South winds 8-15 mph,
with a few higher gust over the ridgetops continues. A few light
rain showers could skirt by across the Fingerlakes and NY
Thruway corridor late morning or midday. Otherwise, most of the
area looks to remain dry through the afternoon hours. It will be
very mild, with above average temperatures. Highs reach 40-45.
Friday night: A better defined, but still weak disturbance
breaks off from the upper level low centered in the Lower
Mississippi Valley. This will bring a quick shot of steady rain
to parts of the area. The best moisture and forcing now looks
to remain along and south of the NY/PA border...but especially
across the Poconos and southern Sullivan County (NY). Adjusted
PoPs further south to account for these latest trends. Now have
categorical PoPs confined basically along and south of
I-84...with likely PoPs across the northern tier of PA over
toward Monticello. Further north, now only carrying chance PoPs
for rain along the Rte 17/I-86 and I-88 corridors. North of Penn
Yan, Cortland and Norwich the latest model trends now keep
things dry Friday night. Rainfall amounts this period look to
range from one half to one inch along and south of I-84...with
a quarter to third of an inch across the northern tier of PA.
Less than a quarter inch of rain is expected from the southern
tier of NY northward. At this time, do not feel these rainfall
amounts will be enough to cause any major hydrologic
concerns...but will continue to monitor this. Temperatures
remain rather mild Friday night, only dipping down between 35-40
in most locations.
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Closed upper low over
the Tennessee valley with double surface lows to the east early
Saturday will drift east over the weekend. Differences remain
between the operational Euro and GFS on the positioning of the
systems and reach to the north of the precipitation field. In
general, the best chance for rain will be over the PA zones,
with the chance tapering off to the north. At this time, it
looks like the heaviest rain will fall south of the area nearer
the mid level inflow to the developing triple point east of NJ.
This greatly lowers the threat of rainfall amounts reaching any
flood threat threshold. No real cold air about either, so the
main precip type will be liquid, at least through the short
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A bit of cooler air begins to drift in Sunday night so there
could be a bit of light snow near the end of the weekend system.
Cold front with much colder air drops in behind the system
Monday with some upper moisture so some snow showers seem
possible or likely into Tuesday in a northerly flow.
High pressure builds in for Wednesday. Later in the day, upper
heights build and a southwest flow develops at the surface
bringing temperatures back above normal for mid week.
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A southeasterly flow of cool, Atlantic air will produce MVFR
ceilings across much of the region overnight, with freezing
drizzle possible near KBGM and eastward. Winds will be light and
Marginal conditions for low level wind shear are forecast to
develop at KRME and KSYR toward sunrise and last for several
Conditions will mainly go to VFR tomorrow afternoon, though a
few terminals will remain MVFR in low ceilings.
Friday night through Saturday morning...Rain showers and likely
restrictions as a system moves through the region.
Saturday afternoon through Sunday...Showers and associated
restrictions possible, especially southern tier down into
Northeast PA. Lower confidence.
Monday and Tuesday...Possible restrictions in snow showers,
especially NY terminals.
Area Forecast Discussion
National Weather Service Des Moines IA
547 PM CST Thu Dec 13 2018
...Updated 00z Aviation...
.DISCUSSION.../Tonight through Thursday/
Issued at 250 PM CST Thu Dec 13 2018
Patchy fog has lingered across much of northern Iowa this afternoon,
with visibilities between 1 to 3 miles. Meanwhile patchy drizzle and
light rain has developed across southern and south east Iowa,
accompanied by patchy fog lowering visibilities into the 2 to 4
mile range. This is associated with low pressure centers to our
south and north which have phased just enough to induce weak
forcing and marginal precip. So far this afternoon models have
been over zealous with precip, although the HRRR caught on later
in the day. Expect this light precip to push east this evening and
remain liquid as temperatures above freezing are expected until
Satellite imagery shows rapid clearing on the back side of this
system as dry air filters in with high pressure building to the
west. As such, have decreased temperatures across northern to
northwest Iowa overnight by several degrees with temperatures likely
to drop off rather quickly as skies clear. Have low teens across
that area, however a few areas in the upper single digits may be
possible depending on how quickly that area clears out tonight. Do
expect fog to develop across northern Iowa as noted in hires
solutions, similar to what we have seen the past several days.
Expect fog to gradually diminish by mid to late morning.
The extended forecast remains quiet as ridging builds across the
area. With this, temperatures well above normal are expected
through the end of the middle of next week. Expect the morning fog
issues of the past few days to likely continue over the next
several days, particularly north and west over areas of snow pack.
Increased temperatures should help to diminish snow pack in these
areas. Model solutions diverge quite a bit towards the end of the
period, however there is some indication that some sort of system
may impact the midwest towards the end of next week.
.AVIATION.../For the 00Z TAFS through 00Z Friday evening/
Issued at 540 PM CST Thu Dec 13 2018
Tonights forecast will be difficult with low CIGs and low VSBYs
across Iowa. Clear skies are entering in the extreme northwest
portion of Iowa. However, recent guidance suggests low stratus
cloud cover will linger over the rest of Iowa during the evening
and overnight hours. For now, MVFR conditions will become IFR
mainly across the north. MVFR conditions can be expected at
terminals in central and southern Iowa. While this is unfolding,
the observations will be bouncing around quite a bit. But IFR
conditions can be expected across the north, with MVFR across
central and southern Iowa this evening. Skies will begin to clear
toward the end of the period.
previously mentioned afternoon forecast discussion reasoning of
patchy to broken rain shower activity moving into the mid state
tonight from the southwest in a more hrly detailed grid evolution
depiction. Based on the reasoning above, along with current sfc
obs and satellite imagery, light rainfall amounts will mainly be
confined to the TN River Valley Region thru 9 PM CST, approaching
western portions of the Nashville Metro Area around midnight, with
numerous light shwrs spreading across the entire mid state region
by 6 AM CST on Fri. Tweaked hrly temp, dewpoint, and wind
speed/direction grids. Current temp trends in line with overnight
forecasted low temp values. Remainder of forecast continues to be
00Z TAF DISCUSSION.
Mainly VFR conditions continue across all sites this evening.
Predominant MVFR conditions roll in overnight/around sunrise
Friday with rain moving in from the south and west. Hi-res
guidance suggests the bulk of the rain lingers through at least
the late afternoon/early evening, along with MVFR CIGS. Ceilings
could go IFR under a steadier rain, but will let later TAF cycles
re-evaluate this possibility.
SE winds tonight slowly become ENE through the day on Friday,
remaining around 5-10 kts with an isolated gust to 15 kts.
Area Forecast Discussion
National Weather Service Blacksburg VA
901 PM EST Thu Dec 13 2018
A developing low pressure system will eject northeast out of the
southern states overnight into Friday before crossing the Mid
Atlantic region this weekend. High pressure follows this system
for early next week.
.NEAR TERM /THROUGH FRIDAY/...
As of 845 PM EST Thursday...
Clouds increasing across the region this evening as the flow
backs well ahead of developing low pressure back across central
Texas per water vapor loop. However evening soundings show quite
a bit of dry air remaining aloft which in line with the latest
HRRR should act to slow down the arrival of precip until the
early morning hours and perhaps closer to dawn far southwest.
Thus slowed down pops a bit overnight before having rain surge
north early Friday as the conveyor belt between the coastal warm
front and the upper system lifts into the area from the south.
This should also help alleviate icing concerns to only the
deeper valleys farther south as guidance shows a steady increase
in dewpoints overnight while clouds limit much cooling. However
snow pack still enough to likely result in some spotty freezing
rain at the onset as it heads farther north by early Tuesday
given colder temps near the ground. Thus kept in a late night
mention along the Blue Ridge for now. Lows mostly in the 30s
with a few spots likely around 30 before rising as the deeper
moisture/rain arrives early in the morning.
Otherwise little change to the going flood watch with still
some concern for coastal front convection to cutoff deeper
moisture transport on Friday, leaving mostly light rain within a
cold wedge and limited melting to produce runoff.
Previous discussion as of 258 PM EST Thursday...
Flood watch posted for Friday afternoon into Saturday afternoon for
East of the Mountains...
Upper low over New York this afternoon will slide east tonight and
push off the New England coast Friday. Weak flat upper ridging will
build between the low to the north and the southern Plains low this
afternoon into tonight. Surface flow has weaken enough to dissipate
the low level clouds in the western mountains this afternoon. An ill-
defined warm frontal boundary will continue lifting northward
tonight across the region. There remains some light precipitation
associated with a weakening shortwave moving across the Piedmont and
warm advection this afternoon. The HRRR dissipates this activity
quickly this afternoon. High pressure to our north will wedge down
the east slopes of the Appalachains tonight, re-enforced by a
sharpening coastal front.
Low pressure system in the lower Mississippi valley will lift
northeast tonight into Friday. There may be enough sub-freezing air
in the boundary layer for a brief period of freezing rain early
Friday morning mainly west of the Blue Ridge north of Route 460 as
precipitation moves in. However any ice amounts would be quite light
before transitioning over to a cold, soaking rain across the
Appalachians. Used Top_down tool to calculate PTYPE tonight into
Friday morning. Overnight low temperatures will vary from the upper
20s in the coldest locations to the mid 30s along the southern Blue
Any freezing rain Friday morning will turn over quickly Friday
morning to all rain. Rain will spread northeast across our area
Friday and may become heavy at time Friday afternoon into Friday
night. As the precipitation advances, the low level wind field will
become quite energetic with some gusty winds expected at the higher
elevations west of the Blue Ridge Mountains. However, winds
should remain below wind advisory levels. Rainfall from tonight
into Friday afternoon will generally vary from around a quarter
inch to around one inch. High temperatures Friday will range
from around 40 degrees in the northern Mountains to the upper
40s in the far southwest mountains.
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 300 PM EST Thursday...
Flood watch continues into Saturday, with best rains occuring Friday
night/early Saturday. A fly in the ointment which would be a good
thing for our area, is if deeper convection along the NC/SC coast
steals moisture transport into the area, though majority of the flow
is out of the south/southwest so not seeing too much of this
happening, but models are shifting axis of heavier rains east.
Another issue will be how much snow melt occurs given cooler temps
and rainfall rates that are not that high. May turn into a case of
minor flooding with ponding water. However, ensembles on the rivers
showing the Dan Basin withe greatest threat of flooding.
The rain will taper to showers Sat afternoon as main axis of lift
shifts into the mid-Atlantic and front moves offshore. Will see
threat of showery weather into Sunday with potential for high
elevation snow if the upper low deepens more, but right confidence
Drying out Sunday evening with lingering upslope showers in the
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 1215 PM EST Thursday...
Operational models are not consistent in the upper pattern next
week, but are at least showing it dry and milder for early to mid
week, as the weekend system has exited. Ensembles favor a northern
stream dominated flow early in the period with heights rising, while
high pressure builds overhead by Wednesday. Beyond midweek, the
GFS/GEFS keep us in a northern stream flow with positive tilt
trough/upper low over Texas, while the ECM increases southwest flow
aloft and has more of a phased look to the trough but weaker.
For now will lean toward a blend of the models and previous forecast
showing dry weather through midweek, the potential for increasing
threat of showers by Thursday. At the moment threat of wintry precip
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
As of 700 PM EST Thursday...
Storm system approaching from the southwest will result in
thickening and lowering of cloud bases overnight from south to
north. High confidence forecast for rain Friday into Saturday
with rain overspreading the forecast area from the south early
Friday. This supports rapid deterioration of flight conditions
with transition to IFR and LIFR flight categories by the end of
the day Friday... low cigs/vsbys then continuing overnight
In addition to the low cigs/vsbys Friday, LLWS will become a
concern. Boundary layer...within 1500 feet of the ground...will
be under the influence of high pressure wedge from the north.
This will favor a northeasterly wind at the surface. Above the
wedge, about 2kft agl, models are forecasting a 35-40 kt Low
level jet, which will become more noticeable Friday afternoon
and into Friday night as the storm system gets closer.
Extended Aviation Discussion...
Upper low is expected to pass overhead Saturday with high
likelihood for IFR conditions associated with occasional
The system is expected to move east of the are Sunday leaving
scattered MVFR conditions with showers and low cigs. Trends
should feature improving conditions overall with some
lingering shower threat Sunday, but then transition to VFR
Monday and Tuesday as drying takes place.
As of 850 PM EST Thursday...
Flood watch continues for areas along and east of the Blue Ridge
from early Friday afternoon through late Saturday. This mainly
the result of a combination of snow melt and runoff from
moderate to heavy rain that is expected Friday afternoon/evening.
Current area river levels remain the highest along the Dan
where more melting has occurred in the last few days, while
readings are much lower heading to the north where the snow pack
has maintained itself a bit more providing little runoff. Just
how much the earlier melt and rainfall into whats left of the snow
cover coincide the keys to seeing at least small stream
flooding and subsequent flooding along the Dan and perhaps lower
Roanoke Rivers this weekend.
Models continue to depict an inch or two of QPF Friday through
Saturday night although the higher rates look to occur along the
southern Blue Ridge per upslope, and across the southeast where
will be closer to elevated convection northwest of the coastal
warm front. However guidance also still showing differences
with potential cutoff of deeper moisture to the southeast via
convection, and less higher rate rainfall in such a deep wedge.
This uncertainty supports just keeping mention of possible river
flooding within the watch, and not hoisting a warning at this
point. Also since forecast minor to even moderate flooding
remains based off projected QPF into the snow, uncertainty
exists given potential for limited melting given the cold
temperatures/dewpoints into Friday evening.
VA...Flood Watch from Friday afternoon through Saturday afternoon
NC...Flood Watch from Friday afternoon through Saturday afternoon
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
712 PM EST Thu Dec 13 2018
.UPDATE (Overnight and Friday)...
00Z water vapor and H4 RAP analysis is showing a vigorous
upper level low closing off over the southern Plains this
evening. It will be this system and associated surface
low/cold front that evolve eastward through the day on
Friday and bring increasing rain/storm chances to west-
central Florida. The system to impact us on Friday/Friday
night is a rather complex one with an atypical frontal
structure and evolution. The front is not going to be very
progressive the next 24-30 hours, especially as it reaches
the eastern Gulf of Mexico/Florida west coast. Several
mid/upper level disturbances moving over this lower level
boundary in conjunction with a highly diffluent upper level
southern stream jet pattern suggest several rounds of storms
may form and pivot eastward into Florida. This setup makes
detailed timing for highest rain chances difficult. Other
than a few showers after midnight for the northern Nature
Coast, most areas should remain dry for the overnight hours.
It appears likely the first round of significant
showers/storm coverage will impact areas north of the I-4
corridor during the morning hours, followed by another round
or two impacting the Tampa Bay Area during the mid/late
afternoon or early evening hours. Yet another round, or the
lingering earlier round from Tampa Bay, will then settle
south and east into our southern and interior southern zones
later in the evening and overnight. These initial rounds of
storm (especially in the afternoon/evening) look to be the
ones with the greatest potential for embedded severe and
rotating storm structures. The initial round into the Nature
Coast may very well have organized convection, but we will
have to see if any of this activity is rooted at the surface
or if its an entirely elevated convective situation.
Forecasters will be closely monitoring the lower level
environment to determine the potential for concerning
elevated radar signals to actually impact at ground level.
Greater potential for surface based convection exists later
in the day across the region due to a combination of
moisture/thermal advection from the south and diurnal
Even after the severe threat diminishes, the slow frontal
movement means we are unlikely to see a defined clearing of
the rain Friday night, but rather lingering elevated chances
for showers/weaker storms for all areas.
Of note: Many of the higher resolution NWP guidance members
are showing a squall-line coming into the I-4 corridor/Tampa
Bay Area region during the evening hours Friday, even late
evening in a few outlier solutions. While the slow progress
of the cold front could certainly make this timing a
reality, the overwhelming bias associated with these model
solutions is to bring MCS/squall-lines into our region late,
sometimes by several hours, compared to what actually ends
up occurring. The reasoning for this lies in the difficulty
all NWP models have dealing with cold pool
generation/evolution and propagation under and ahead of the
convection. This is especially true over the open waters of
the Gulf of Mexico. These cold pools of air very often move
quicker in reality compared to the model simulations, and
therefore we see the rain/storms arrive and exit quicker
than the model ensembles will forecast. this bias has been
applied to the current forecast related to timing of higher
rain chances / severe weather threat.
.AVIATION (14/00Z through 15/00Z)...
VFR conditions as BKN-OVC mid deck slowly lowers through the
night. E and ESE winds under 10 knots overnight begin to
increase between 12-15knots with higher gusts and become SE
to SSE AFT 14-15Z. Approaching cold front bring increasing
chances for showers/storms to KTPA/KPIE/KLAL/KSRQ by early
to mid afternoon and then continue into the evening hours. A
few storms later afternoon/evening may be strong to severe.
Rain/storm chances look to wait until after 21Z for
KPGD/KFMY/KRSW but then linger through the evening and
.Prev Discussion... /issued 246 PM EST Thu Dec 13 2018/
..SLIGHT RISK OF SEVERE THUNDERSTORMS FRIDAY...
..HAZARDOUS CONDITIONS ARE EXPECTED TO IMPACT MARINE WATERS AND
Robust mid level low over TX this afternoon takes an easterly
track...as ridging east of FL moves away...along the western Gulf
coast Fri then over the southeastern states during Sat. At the
surface - ridging over FL and the east Gulf slides to the east as
the surface reflection of the TX mid level low drags a cold front
across the Gulf. The front reaches the west-central and southwest
FL coastal waters Fri then slips across the state to the Atlantic
Moisture and wind fields begin to increase over the Gulf later
tonight ahead of the approaching system...shift into the coastal
waters early Fri...then cross west-central FL Fri morning into the
afternoon and southwest FL afternoon and evening. These times are
first guess and will be adjusted over the next couple of forecast
cycle. A squall line or two is expected to form ahead of the
front with strong to severe thunderstorms that can produce
damaging wind gusts...tornadoes or waterspouts...and locally heavy
rainfall with flooding. The most active weather will be moving
east across the state toward the Atlantic late Fri night. Large
waves and swells will be generated in the western Gulf that
translate onto area breaches for the weekend with a high risk of
rip currents expected.
For Sun - Thu: The mid level low exits the southeastern coast early
in the period as ridging builds into the nation/s mid-section from
Mexico then slides east through Wed. Surface high pressure settles
into the western Gulf Sun then tracks to the eastern seaboard by
midweek. On Thu a mid level short wave trough/low moves into the
southern plains with a surface low/cold front forming on the western
Gulf coast. The upper and surface ridging dominate for much of the
period with dry seasonable temperatures. Moisture increases enough
by Thu to support some showers and a few thunderstorms.
Increasing winds ahead of an approaching storm system will require
small craft advisories on some of the waters tonight...and spread to
the rest of the waters as the system moves into the coastal waters
early Fri with thunderstorms and possible waterspouts. The
front crosses the state Sat then moves out over the
Atlantic. This system is generating large waves and swells
in the western Gulf that will translate into the local
waters for perhaps much of the weekend. High pressure begins
to build into the western Gulf Sun then slides to the
eastern seaboard by midweek with winds veering and
Atmosphere continues very moist with no low humidity concerns. Storm
system coming in from the west will bring showers...thunderstorms...
and locally heavy rainfall mainly Fri with some showers and a few
storms into Sat.
.Preliminary Point Temps/PoPs...
TPA 65 76 65 72 / 10 90 90 30
FMY 66 81 69 74 / 0 40 70 40
GIF 64 80 65 74 / 10 80 70 40
SRQ 66 76 67 72 / 10 90 90 30
BKV 63 78 65 72 / 30 100 90 30
SPG 66 76 65 72 / 10 90 90 30
Gulf waters...Small Craft Advisory until 7 PM EST Friday for Waters from
Englewood to Tarpon Springs FL out 20 to 60 NM-Waters
from Tarpon Springs to Suwannee River FL out 20 to 60
Small Craft Advisory from 1 AM to 7 PM EST Friday for
Waters from Bonita Beach to Englewood FL out 20 to 60
Small Craft Advisory from 4 AM to 7 PM EST Friday for
Coastal waters from Bonita Beach to Englewood FL out
20 NM-Coastal waters from Englewood to Tarpon Springs
FL out 20 NM-Coastal waters from Tarpon Springs to
Suwannee River FL out 20 NM.