Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/16/17
Area Forecast Discussion
National Weather Service Columbia SC
1003 PM EST Sun Jan 15 2017
.SYNOPSIS...
High pressure to the north will push a little cooler air into
the forecast area Monday. The high will be off the coast and a
southerly flow on the backside of the high will dominate
Tuesday. A cold front and associated moisture will be in the
area Wednesday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A downstream upper ridge will build east over the region
tonight as an upper low over southern New Mexico lifts
northeastward. At the surface, high pressure over the Eastern
Seaboard will ridge into the area promoting light east/southeasterly
surface winds. Models show the deepest moisture in the northern
portion of the area with PWAT values around 1 inch. Have
continued to indicate a slight chance of showers in this area
tonight due to the combination of moisture and weak lift.
Moisture near the surface coupled with light winds and nocturnal
cooling is expected to result in areas of fog overnight and
early Monday as well. Well above normal low temperatures
expected once again in the 50s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Easterly flow will continue through the day Monday with a front
well north of the region and weak ascent across the area. This
will keep mostly cloudy skies across the area with slight
chance pops across the far western Midlands and northern CSRA.
With the increased clouds temperatures Monday will be cooler
with afternoon highs ranging from the lower 60s along the NC
border to the low 70s in the CSRA...with lows Monday night in
the upper 40s to low 50s. Situation will be slow to change
Tuesday with some change Tuesday night as a cold front
approaches from the west. This will keep partly cloudy skies
over the eastern half of the forecast area with mostly cloudy
elsewhere. With a bit less cloudiness and low-level flow
turning more southerly temperatures will be slightly warmer with
mid 60s to low 70s for daytime highs and mid 50s for overnight
lows.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Pattern will remain active through the long term as the upper-
level flow will be highly amplified. Models agree on a system
crossing the forecast area Wednesday with drier air briefly over
the region Wednesday night as the cold front moves offshore. As
high pressure marches through the area Thursday the Gulf will
once again open up with a plume of moisture extending northward
through the western Gulf States. As high pressure moves offshore
Friday the moisture will move eastward bringing showers back into
the forecast. The pattern will remain active for next weekend
as another upper low moves into the southwestern US allowing
the Gulf of Mexico to remain open and a series of systems
expected to move through the area.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Weak moisture convergence associated with the weak boundary and
nocturnal cooling will help support stratus and fog development
tonight. The guidance is in good agreement indicating widespread
IFR conditions developing. Leaned toward the GFS LAMP and HRRR
for the timing. The NAM and GFS indicated diurnal improvement
with VFR conditions during the afternoon. The pressure gradient
will remain weak with light wind.
EXTENDED AVIATION OUTLOOK...High low-level moisture associated
with an onshore flow combined with noctural cooling indicates
widespread stratus and fog may occur during the late night and
early morning hours Tuesday. Widespread restrictions may occur
in showers associated with frontal systems mainly Wednesday and
Friday.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
646 PM CST Sun Jan 15 2017
.UPDATE...
The forecast has been updated to include the mention of Tornado Watch
#8, which is in effect for the Hill Country and portions of the I-35
corridor until midnight. In addition, a Severe Thunderstorm Watch
remains in effect for the Rio Grande plains and Edwards plateau until
10 PM.
&&
.AVIATION...
Concerns continue to be centered on the chance for showers and
thunderstorms this evening and overnight. We will continue to mention
a TEMPO group at DRT through 04Z as storms continue to develop near
and to the west of the terminal. After 04Z, shower and thunderstorm
activity is expected to move east of the terminal. Farther east
across the I-35 corridor, isolated showers will continue this evening
and we will mention VCSH. Early Monday morning, we still expect a
line of convection to move in from the west between 08-11Z along
I-35 and will mention TEMPO groups at our sites. Once the line passes
east of the terminals, we expect some lingering showers through mid-
morning.
&&
.PREV DISCUSSION... /ISSUED 305 PM CST Sun Jan 15 2017/
SHORT TERM (Tonight through Monday Night)...
Strong to severe convection is about to enter the western boundary of
our forecast area, northwest of Del Rio. This convection is being
generated by a strong shortwave trough, unstable Gulf air, and a
slowly northward moving warm front. High resolution mesoscale models
have been consistent in depicting a thin MCS with embedded supercell
structures. The Texas Tech and NSSL WRFs have verified best so far
with timing and linear mode, with recent HRRR runs showing a more
broken line of supercells. Overall, prior forecasts are on track and
we expect the line to sweep across the area, generally along and
north of U.S. 90. The line should weaken with time, and reach the
I-35 corridor around 05-06Z. While one or two brief tornadoes are
possible, the main severe threats will be large hail and damaging
winds. Rainfall will average 1/2 to 1 inch, although some locations
in the Edwards Plateau, Hill Country, and Metro Austin could receive
up to 2-3 inches by daybreak Monday. Showers and thunderstorms will
linger on the coastal plains Monday, but rainfall amounts should be
1/4 inch or less.
LONG TERM (Tuesday through Sunday)...
Highly amplified and progressive flow will continue across the CONUS
through the next 7-10 days. This will bring a progression of fairly
sharp shortwave troughs through a general longwave trough over the
Plains. The net result for our area will be a cold front bringing
colder conditions Wednesday and Thursday, then back to above normal
temperatures Friday through Sunday before another cold front. PoPs
will be in the forecast through Friday, although rainfall should be
light. Just beyond this forecast period is another strong front and
the potential for strong convection, then a colder, drier period.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 61 71 51 57 49 / 80 40 30 60 50
Austin Bergstrom Intl Airport 62 71 52 58 49 / 80 40 30 60 50
New Braunfels Muni Airport 62 72 54 58 51 / 70 40 40 60 50
Burnet Muni Airport 55 69 46 55 46 / 90 10 20 50 50
Del Rio Intl Airport 50 72 51 60 50 / 60 0 - 40 30
Georgetown Muni Airport 58 69 48 56 47 / 90 30 30 50 50
Hondo Muni Airport 60 75 55 60 51 / 70 10 20 60 50
San Marcos Muni Airport 62 72 53 59 50 / 70 40 40 60 50
La Grange - Fayette Regional 66 72 57 61 53 / 70 60 50 50 50
San Antonio Intl Airport 62 74 55 60 52 / 70 20 30 60 50
Stinson Muni Airport 62 74 57 61 53 / 70 20 30 50 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Mesoscale/Aviation...24
Synoptic/Grids...Allen
Public Service/Data Collection...30
Area Forecast Discussion
National Weather Service Lincoln IL
857 PM CST Sun Jan 15 2017
.UPDATE...
Issued at 848 PM CST Sun Jan 15 2017
The band of light rain and sleet that pushed across the area late
this afternoon into this evening continues to track northeast out
of the area with one more additional area of light rain.
Temperatures have held around the freezing mark or slightly above
that as the rain moved through so no significant icing problems
were seen. Once this last area of light rain moves through it
appears we will see mainly some spotty light rain/drizzle and some
patchy fog for the rest of the night with the possibility for a
little freezing rain or drizzle along and especially north of the
I-74 corridor. Overnight temperatures are expected to remain
nearly steady, especially across the north with steady or slowly
rising temperatures across the south late tonight as the next
storm system starts to push towards our area on Monday bringing
rain to the forecast area along with mild temperatures. With the
lingering chance for some freezing rain or drizzle overnight,
there will be no changes made to the current Winter Weather
Advisory across the north. We should have the update out by
915 pm.
&&
.SHORT TERM...(This evening through Monday)
ISSUED AT 307 PM CST Sun Jan 15 2017
Will continue the winter weather advisory from Fulton, Tazewell and
McLean counties northward tonight into Monday morning for light
icing up to a tenth inch possible along with some sleet. Latest
model runs are warming surface temps a bit quicker late tonight into
Monday morning, so the winter weather advisory might be able to end
sooner.
An area of light rain was along and south of a Macomb to Lincoln to
Terre Haute line at mid afternoon, with the northern fringe of
precipitation mixed with some light freezing rain and sleet. Surface
temperatures were mostly just above freezing over CWA, expect still
30-32F from Galesburg to Jacksonville west where mixed light
precipitation occurring. 1030 mb high pressure over the southern
great lakes was keeping northeast CWA from Lincoln ne dry so far
today with overcast mid level clouds around 10k ft. Light
precipitation was from overrunning of a warm front just south of TN
into central Texas to 1006 mb surface low pressure in sw Texas.
Aloft a 555 dm 500 mb low was spinning just east of El Paso Texas.
Hi resolution models like the HRRR and ARW (to a lesser extent with
the RAP model) lift the light precipitation ne across rest of
central IL late this afternoon and this evening. Then more
precipitation develops later tonight over western CWA and then
spreads ne across rest of area on Monday. Continued small chances of
thunderstorms late Monday afternoon sw of Springfield. The thermal
profiles still support best chances of light freezing rain north of
I-72 this evening, shifting nw of a Rushville to Bloomington line by
sunrise Monday, and nw of a Galesubrg to Henry line by 9 am Monday,
as temps rise above freezing. Lows tonight range from around 30F
over northern CWA where winter wx advisory is posted, to the mid 30s
from I-70 southeast and may be nearly steady or even rise slightly
later tonight. Milder highs Monday range from low to mid 40s over
northern CWA, to the low to mid 50s in southeast IL with southeast
winds 8-15 mph.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 307 PM CST Sun Jan 15 2017
The upper low currently over western TX will eject northeastward
across the southern Plains reaching NW Missouri by Monday evening.
As it does so, warm moist southerly flow ahead of the low will
result in instability characterized by MUCAPE values around 200
J/kg, which should allow for isolated thunderstorms...continuing
after midnight east of I-55. Moderate rain amounts around 1/2 inch
to 1 inch should accompany this portions of the storm as the surface
low moves through northern IL. Low temperatures should only reach
around 50 near the Indiana border to the upper 30s in Galesburg as
the cold front sweeps across the state late in the night. As
temperatures remain above freezing and saturation depth decrease
dramatically behind the upper wave, precipitation type should remain
all rain with a loss of ice aloft. A bit cooler Tuesday with some
lingering drizzle/light rain toward the northeast, with highs
ranging from near 40 in Galesburg to above 50 in Lawrenceville.
Fair weather mid week as high pressure shifts east across the
central U.S. with highs in the mid 40s to lower 50s and lows upper
20s to mid 30s.
Pattern transitions to a longwave trough over the west and ridge
over the east for late in the week and next weekend. The result will
be a series of waves ejecting out of the southwestern U.S. toward
the Midwest. Although timing and track uncertainties remain, this
should bring mild temperatures with periodic chances for rain Friday
through the weekend. Current model consensus places a chance for
precipitation Friday and Sunday as indicated in afternoon forecast
package, however there will undoubtedly be refinements in the timing
and track of these systems in the upcoming days. As highs/lows
likely to be in the 50s/40s through this time, all rain expected at
this point.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 505 PM CST Sun Jan 15 2017
Latest surface observations indicate a large band of IFR to LIFR
cigs were located from Springfield to just south of Decatur and
are expected to edge north tonight. Latest forecast soundings
suggest our northern TAF sites (PIA and BMI) should see the IFR
cigs around midnight and once they arrive, it appears they will
be with us through the rest of the forecast period. A band of
light rain and sleet was track east across the TAF sites late
this afternoon and will continue to drift east early this evening
with most of the precip shifting away from our area in the 01z to
03z time frame. Surface temperatures around KBMI may slip a degree
below freezing for a time so we may see a brief period of -FZRA
and sleet early this evening before the precip moves out. Light
easterly winds of less than 10 kts tonight will turn more into
the southeast at 10 to 15 kts on Monday ahead of a approaching
storm system.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST Monday for ILZ027>031-
036>038.
&&
$$
UPDATE...Smith
SHORT TERM...07
LONG TERM...37
AVIATION...Smith
Area Forecast Discussion
National Weather Service Indianapolis IN
1000 PM EST Sun Jan 15 2017
.UPDATE...
The Near Term Section has been updated below.
&&
.SYNOPSIS...
Issued at 700 PM EST Sun Jan 15 2017
A low pressure system originating in the Southern Plains will be the
main focus early in the forecast period. Moisture will be limited
tonight though with just scattered light showers early, patchy
drizzle, and a slight chance across the northern counties for
freezing rain or patchy freezing drizzle for a few hours late. Rain
showers will then increase across the forecast area tomorrow from
west to east. Increased forcing could also result in some isolated
thunderstorms on Monday night. As the system pushes farther east,
dry conditions will prevail on Wednesday and Thursday.
Further out, three separate systems will approach from the
southwest, bringing periodic rain chances late in the week and next
weekend.
&&
.NEAR TERM /Rest of Tonight/...
Issued at 1000 PM EST Sun Jan 15 2017
HRRR and RAP continue to show some spotty light precip continuing
across the area through at least 9z or so and their soundings
support this, but very little if any qpf. Decided to add patchy
light drizzle to the area through much of the night as a result. A
quick check of forecast temperatures show a few hours below freezing
in some of the northern counties, so in those added patchy light
freezing drizzle. Any freezing should be pretty short-lived as
temperatures are forecast to start to increase late during the
overnight, but during those few hours it could produce a few slick
spots on roads in the north.
Low temperatures remain unchanged from afternoon issuance, with low
30s in the north to mid to upper 30s in the south.
&&
.SHORT TERM /Monday through Wednesday/...
Issued at 242 PM EST Sun Jan 15 2017
The main focus of the short term period will be a low pressure
system approaching from the southwest. Originating in the Southern
Plains, this system will track through the Missouri Valley on
Monday, advecting much warmer air ahead of it. Temperatures will
soar above normal on Monday and Tuesday with highs topping off in
the mid to upper 50s across portions of Central Indiana.
Isentropic lift with aforementioned system strengthens most during
the Tue 00-12Z time frame. As a result, will mention isolated
thunderstorms during that period which coincides with SPC`s day two
convective outlook.
Rain showers will linger through Tuesday and across the northern
sections of central Indiana on Tuesday night. However, thunderstorm
threat will have ended by then as low pushes farther into the Lower
Great Lakes Region. A wintry mix will be possible briefly on
Tuesday night across the northeastern counties on the tail end of
the system, but moisture will be limited by that point. So, no
accumulations are expected.
Further out, GFS and Euro start to differ on day 4. The GFS is
trending toward a moisture deprived upper low, while the Euro is
showing high pressure. Either way, will trend toward a dry forecast
for Wednesday. Temperatures by Wednesday will be a tad cooler with
highs in the low to upper 40s.
&&
.LONG TERM /Wednesday night through Sunday/...
Issued at 200 PM EST Sun Jan 15 2017
Models consistent in dry weather through at least Thursday morning
as an upper ridge moves over the area. Then, three straight
southwest systems will bring warm weather and periodic rain shower
chances to the area late this week and weekend. The ECMWF has been
running the quickest east with these systems compared to the GFS.
Regional blend goes along better with a slower solution that is also
preferred by WPC. So, will go with that. Highs could reach 60
degrees or so next week.
&&
.AVIATION /Discussion for 160300z TAF issuance/...
Issued at 930 PM EST Sun Jan 15 2017
Ceilings at KIND have improved, but MVFR visibility remains. Think
cloud deck will drop back to MVFR in a few hours, say 5z, and then
drop further within a few hours of that. Previous discussion
follows...
Some spotty shower activity could be seen at the sites especially
in the next couple of hours, but the main impact to operations
will be the ceilings. These are expected to stay low in the case
of KBMG where 600 ft are already in place, and to drop everywhere
else where MVFR to VFR is currently the rule. Should see them drop
to around 300 ft everywhere during the overnight hours, with
mainly MVFR visibilities with some good low level moisture but
still some boundary layer mixing to keep vsbys from getting too
low. Little improvement is expected through the day on Monday to
ceilings with them just bouncing between low and high IFR. Monday
afternoon/evening rain chances will pick up as a low pressure
system approaches from the plains.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD/CP
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...CP
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
947 PM CST Sun Jan 15 2017
.UPDATE...
Issued at 924 PM CST Sun Jan 15 2017
Most of the light rain has shifted northeast of our forecast area
this evening. There is still fog across much of the area along with
patchy drizzle. The HRRR and latest NAM model runs bring another
round of rain northeastward into central and northeast MO and
west central IL late tonight/early Monday morning well ahead of an
approaching upper level low and associated surface low moving into
the central Plains and north of a warm front. Temperatures in
northeast MO and west central IL were still near the freezing
mark this evening, but these should be slowly rising overnight.
GKS
&&
.SHORT TERM... (Through Late Monday Afternoon)
Issued at 326 PM CST Sun Jan 15 2017
Freezing line continuing to lift northward through region this
afternoon. So freezing rain slowly changing over to all rain from
south to north. Have expired/cancelled Ice Storm Warning and
replaced portions over northeast MO, west central IL with a Freezing
Rain Advisory til 6 pm. Any ice accumulation in this area will be
less than a tenth of an inch.
Otherwise, most locations to see a bit of a break from precipitation
til after 06z tonight. Main shortwave/trof over southwestern US to
lift northeastward towards area with increasing surface temps and
low level moisture. So precipitation chances to be on the increase
after 06z Monday. During the day on Monday, surface dewpts to rise
into the low 40s to low 50s, decent low level jet and MU capes
between 100 and 500 J/kg, so slight chance of thunderstorms, mainly
during the afternoon hours.
As for temperatures, with system lifting northeast towards region,
will see steady or increasing temperatures tonight. Decent WAA ahead
of system on Monday with highs in the low 40s to upper 50s, a good
10 to 15 degrees above normal for this time of year.
Byrd
.LONG TERM... (Monday Night through Next Sunday)
Issued at 326 PM CST Sun Jan 15 2017
The models are in relatively good agreement with the large scale
features Monday night into early Tuesday with the upper low moving
from NW MO into the lower Great Lakes. The associated surface low
will follow a similar track with the southward trailing cold front
sweeping across the entire area Monday night, and located east of
the CWA by 12z Tuesday. Good deep large scale ascent will continue
to favor showers/rain through the warm sector ahead of the front
on Monday night, with weak instability supporting isolated
thunderstorms. Tuesday will be largely dominated by weak CAA in
the wake of the cold front and extensive post-frontal stratus.
Temperatures while cooler than Monday, will still be above
average. There is a secondary northern stream short wave trof
progged to dig from the northern Plains into the mid/upper MS
Valley in the Monday night-Tuesday Night time frame. The GFS is
the odd model out with a slower solution showing more digging, and
this could maintain clouds longer and even help generate some
spotty pcpn if correct. At this time it has been largely discounted.
By Wednesday, a low level WAA regime gets well underway and this
should promote well above average temps at least on Wednesday. The
models diverge during the later part of the week with the
evolution and northeast movement of the lagging southwestern U.S.
upper low/trof. Both the GFS and ECMWF are similar bringing this
lifting upper trof/low into the MS Valley in a negatively-tilted
fashion however differ by timing on the order of 18 hours, with
the ECWMF faster centered from late Wednesday night-Thursday
night. Regardless of timing, temps should be above average, its
just how much above average and then timing on the attendant
threat of showers and maybe thunder. In the wake of this system,
deep southwesterly flow will evolve into the weekend keeping above
average temps going strong.
&&
.AVIATION... (For the 00z TAFs through 00z Monday Evening)
Issued at 542 PM CST Sun Jan 15 2017
The areas of light rain, freezing rain in UIN, should move out of
the area later this evening, but patchy drizzle may continue. Very
low stratus cloud cigs of 500 feet or less will continue through
at least Monday morning along with fog. Rain will spread eastward
into COU late tonight and into the rest of the taf sites early to
mid morning ahead of an approaching low pressure system and north
of a warm front. There may be some embedded thunderstorms, but
will leave TSRA out of the tafs for now. East-northeast surface
wind will veer around to a southeast direction on Monday and
strengthen as the surface ridge centered over the Ohio Valley
region shifts eastward.
SPECIFICS FOR KSTL: The areas of light rain should move out of
the area later this evening, but patchy drizzle may continue. Very
low stratus cloud cigs of 500 feet or less will continue through
at least Monday morning along with fog. Rain will spread eastward
into the STL area Monday morning ahead of an approaching low
pressure system and north of a warm front. There may be some
embedded thunderstorms, but will leave TSRA out of the STL taf for
now. East-northeast surface wind will veer around to a southeast
direction on Monday and strengthen as the surface ridge centered
over the Ohio Valley region shifts eastward.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Melbourne FL
1005 PM EST Sun Jan 15 2017
.DISCUSSION...
No significant changes to current forecast. Thin cirrus will
continue to stream overhead overnight with occasional marine
stratocu pushing onshore. Cannot rule out some sprinkles along the
Treasure coast falling out of the wetter stratocu but chance of
measurable rain looks too low to mention.
Tonight-Monday (previous)...Mid level ridge over Florida will weaken
sightly as the high center drifts slightly southward. The surface
high pressure ridge along the SE seaboard this evening will drift
eastward into the Atlantic on Monday. This results in slight veering
of the mean wind flow from east to ESE, with sensible weather
conditions (sky cover, temps, nil pops) similar to the past 24
hours. Some patchy, shallow late night mist/fog possible inland, but
probably more like this morning`s milquetoast visibility reductions
rather than Saturday`s more dense fog/stratus.
Mins tonight in the U50s inland and L60s near the coast. Max temps
in the U70s to near 80F inland, under a light onshore ESE breeze.
&&
.AVIATION...mainly VFR. MOS/LAMP guidance indicating fog late
tonight north of MCO but HRRR and local WRF models do not show
significant vsby reductions over EC FL. So have low confidence on
extent of fog tonight and have kept TAFs VFR. On Monday, E/SE winds
around 10 knots.
&&
.MARINE...
A moderate E to ESE breeze will continue with the long (10-11sec)
period E swell slowly decaying. Seas 3-5FT tonight decreasing to 3-
4FT by Monday afternoon. No headlines.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 60 75 58 78 / 10 10 0 0
MCO 59 79 59 81 / 0 10 0 0
MLB 63 77 61 79 / 10 10 0 0
VRB 63 77 60 79 / 10 10 0 0
LEE 57 79 58 81 / 0 10 0 0
SFB 58 79 59 81 / 0 10 0 0
ORL 59 79 60 81 / 0 10 0 0
FPR 63 77 60 78 / 10 10 0 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
Kelly/Weitlich
Area Forecast Discussion
National Weather Service Paducah KY
853 PM CST Sun Jan 15 2017
.UPDATE...
Issued at 843 PM CST Sun Jan 15 2017
The measurable rainfall seems to be near an end in the northeast,
and the latest HRRR runs indicate that it may very well remain dry
throughout the area for the rest of the night. Updated to trend
drier through 06Z, but still have some lower chance PoPs coming
into the west toward morning.
The bigger story tonight will be fog which is prevalent over the
southern half of the region at this time. A few sites along the
southern border of the region are under a mile, but to this point
have not seen any reports of 1/4SM. Have added areas of dense fog
to the forecast. Held it out until near sunrise in the EVV Tri
State, but latest short term guidance indicates that even the
northeast will see some decent fog by morning.
I would prefer to see some observations/reports of dense fog
before pulling the trigger on a Dense Fog Advisory, but will
probably be making a decision in the next hour or so. It seems
most likely over southeast Missouri and the Tennessee border areas
of west Kentucky.
UPDATE Issued at 612 PM CST Sun Jan 15 2017
Updated aviation discussion.
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 157 PM CST Sun Jan 15 2017
High rain chances return to the region Monday and especially
Monday night as a cold front and associated H50 short wave
approach from the west, and a surface low tracks northeastward
through through the Plains and into the Midwest. Southerly winds
will likely push high temperatures Monday afternoon well into the
50s north/60s south.
Still not too excited at this time on strong/severe threat given
overall lack of instability. MU CAPES progged to remain
limited...in the 100-300 J/KG range. More likely just a few
isolated storms here and there with some locally heavy downpours.
Things could change a bit if more than anticipated instability
levels were to work northeast into the region from AR. As far as
rain amounts are concerned, could be some decent amounts up over
1/2 inch, especially along and south of the OH River.
High pressure moving in behind this system will be of Pacific
origin, so should stay with above normal temps as we head into
Tue/Wed time frame. May even finally see a long awaited return to
some decent amounts of sunshine by Wednesday. Tuesday looks to be
quite breezy (west winds) with quite a bit of residual cloud
cover.
.LONG TERM...(Wednesday through Sunday)
Issued at 157 PM CST Sun Jan 15 2017
The extended forecast period begins with the ridging in place at the
surface and aloft in the wake of the exiting weather system on
Tuesday.
The mean hemispheric pattern suggests that the strong zonal flow
will slowly translate toward the West Coast of the U.S. while ridging
builds aloft along the eastern U.S. by the middle of this week. This
will create an oscillating fire hose effect, generating eddies in
the mean flow until the zonal flow from the Eastern Pacific pushes
into the southwest quarter of the U.S. over the weekend.
The closed low that moved into Western Texas today (Sunday) from the
Northern Mexico this morning is expected to maintain enough
troughiness in the Western U.S. to support another sharpening
shortwave into the backside of the trough. This next shortwave will
be the likely generator of precipitation from the Lower Mississippi
Valley as it moves along the eastern axis of the mean trough,
eventually dampening the ridge over the WFO PAH forecast area on
Thursday.
This circulation will bring moisture and instability into the WFO
PAH forecast area Thursday into Friday, bringing the next chance for
rain and a few thunderstorms to the area.
Beyond Friday, the moisture, instability, and flow will become more
chaotic with periodic chances for rain for the remainder of the
weekend. Anticipate that the best chances for rain will remain
higher to the south and lesser to the north across the WFO PAH
forecast area.
Preferred the ECMWF solution over the GFS Solution for most of the
extended period, with the NAM-WRF presenting a good median position
at the beginning of the extended period. The preference to the ECMWF
is also shared by the folks at NCEP.
&&
.AVIATION...
Issued at 612 PM CST Sun Jan 15 2017
An atmosphere at or near saturation north of a warm front will
remain conducive to IFR/LIFR cigs and MVFR/IFR vsbys this evening
and overnight. The worst conditions will probably be in southeastern
MO and the Purchase area of KY. Some areas of drizzle are possible
by mid morning Mon, followed by light rain in the afternoon and
generally improving cig/vsby conditions, especially in the Pennyrile
region of KY. Meanwhile, surface winds will gradually veer to the
south or southeast by Mon afternoon.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
UPDATE...DRS
SHORT TERM...GM
LONG TERM...Smith
AVIATION...DB