Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/23/19
AREA FORECAST DISCUSSION
National Weather Service Albany NY
936 PM EST Sun Dec 22 2019
.SYNOPSIS...
Dry conditions will persist through the next several days.
Temperatures will be relatively warmer this week compared to the
past several days, with Monday expected to be warmest day of
the week. A cold front will cross the region Monday night, with
cooler air filtering in for Christmas Eve into Christmas day.
Temperatures will still average above normal through much the
week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 930 PM EST...Patchy of dense stratus has slowly lifted
northward over portions of Herkimer and Hamilton Counties and
latching on across the southern Greens and northern Berks per
the enhanced nighttime microphysics GOES imagery. 00Z sounding
shows the nocturnal inversion below H850 where moisture is able
to spread under the inversion. HRRR low level RH fields suggest
this mesoscale feature will lift northward or dissipate as we
will continue to adjust sky coverage a bit from previous
forecast. Also, as winds are near calm, temperatures are also
responding as we will lower overnight lows a couple more
degrees. However, diversity of temperatures are quite
challenging with large spread over short distances. Attempted to
account for these mesoscale effects with this update. Otherwise,
low level jet magnitudes increase overnight from the west with
weak warm advection.
Prev Disc...Temperatures have warmed into the 30s and 40s this
afternoon, with the coldest temperatures still in valley
locations form Albany north and east and warmest readings in
higher terrain areas south and west of Albany. Some high level
clouds continue to pass through the region, but skies averaging
mostly clear to partly cloudy. Dry conditions will persist
tonight, as our area will be between a southern stream system
over the SE CONUS and a northern stream system well north in
Canada. A few extra clouds may drift into the Adirondacks
tonight well ahead of this disturbance.
Temperatures will be milder than previous nights (upper 10s to
upper 20s) with a slight breeze, but still went below guidance
as forecast soundings indicate the low level inversion
strengthening tonight.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Monday looks to be the warmest day of the week, as we are
expected better mixing compared the past few days along with
warming temperatures aloft. There will be more of a pressure
gradient, which will allow for westerly winds to increase by
late morning into early afternoon. Will trend forecast towards
the cooler side of guidance, but not below. This translates to
highs in the mid to upper 40s in most areas, with possible 50+
readings in the mid Hudson Valley.
A cold front is expected to move across the region Monday
night. Winds will shift to the northwest and become gusty during
the evening and early overnight hours behind the front. Winds
will quickly become lighter on Tuesday, as a ridge of high
pressure extending southward from an anticyclone centered over
central Quebec moves in. So another dry day is anticipated, but
with temperatures cooling down about 10 degrees compared to
Monday.
Dry conditions and seasonably cold temperatures in store for
Christmas Eve night, with the surface ridge positioned over our
region. An increase in mid level moisture could result in some
added cloud cover, especially from around the Capital District
westward.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Rather low confidence forecast leading into this last full week of
2019 as timing and strength of Pacific origin short waves will have
implications to sensible weather for the long term period.
Wednesday, still several discrepancies with the position of east-
west frontal boundary as all available global guidance suggest this
frontal zone will be in the vicinity with minimal moisture to work
with at this time. For now, we will keep the forecast dry under
variable cloudiness with temperatures mainly into the 30s with some
lower 40s for the Capital Region and points southward through the
Hudson River Valley.
From here, just how far south this frontal zone gets remains to be
seen. The GFS is the most aggressive with a stronger surface high to
our north with the ECMWF weaker with more clouds and the increase
probabilities for wintry type precipitation late Thursday into
Thursday night from west to east. For now, and per collaboration,
we will hold PoPs back during the daylight hours and increase toward
slight chance Thursday night.
Friday, either the frontal zone remains in the vicinity or lifts
north of the region. This is where the upstream Pacific short waves
will have implications to the forecast as the GFS is the most
aggressive when compared to the remainder of the global guidance. As
per the previous forecast, we will keep chance PoPs with a wintry
mix of rain/snow depending on those temperatures. MOS values are
rather close as we will keep close to those values with this update.
Then into the first half of the weekend, even lower confidence
forecasts as the GFS opens up the Pacific wave(s) with the ECWMF,
GGEM, ICON keeping the upper low intact and further upstream. So per
coordination with neighboring offices, we will keep slight chance to
chance PoPs in the forecast grids and near seasonable
temperatures.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
VFR conditions prevail through the TAF period.
Watching a patch of stratus across the Dacks and developing into
the southern Greens where CIG levels were borderline VFR/MVFR.
Expectations are for this stratus to expand a bit yet should be
few-sct for KGFL-KALB-KPSF to keep the VFR forecast.
Have continued LLWS mainly tonight into Monday at all sites
except KPOU. Surface winds will remain light. Meanwhile, low
pressure across southern Canada combined with high pressure
across the mid Atlantic will tighten the height gradient across
our area. This will push winds at 2K feet to 30-40 knots tonight
into Monday. Right now it looks like the strongest winds will
remain north of KPOU.
Outlook...
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Christmas Day: No Operational Impact. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: Low Operational Impact. Slight Chance of SHSN.
Friday: Moderate Operational Impact. Chance of SHRA...SHSN...RA...SN.
&&
.HYDROLOGY...
Dry conditions are expected for the next several days. Cold
temperatures will persist through tonight, with moderating
temperatures on Monday. Some gradually melting is possible
during the daylight hours this week as temperatures rise above
freezing across much of the area, with re-freezing occurring
each night. This trend may continue through much of the week, as
temperatures are forecast to be slightly above normal.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.CLIMATE...
Christmas Day Records
Albany NY
Records date back to 1874
Normal: High 33 / Low 18
Last Year: High 35 / Low 24 / AvgTemp 29.5 / Pcpn Trace / Snow Trace
Max Temperature: 66 degrees 1889
Min Temperature: -22 degrees 1969
Lowest High Temperature: 3 degrees 1983 and 1980
Highest Low Temperature: 46 degrees in 1964
Warmest Average Temperature: 54 degrees 1964
Coldest Average Temperature: -8.5 degrees 1980
Wettest: 1.79 inches 2002
Snowiest: 19.2 inches 2002
Glens Falls NY
Records date back to 1893 with some gaps in the data
Normal: High 31 / Low 12
Last Year: High 32 / Low 14 / AvgTemp 23 / Pcpn 0.00
Max Temperature: 62 degrees 1964
Min Temperature: -27 degrees 1980
Lowest High Temperature: 4 degrees 1968
Highest Low Temperature: 43 degrees in 1964
Warmest Average Temperature: 52.5 degrees 1964
Coldest Average Temperature: -11 degrees 1980
Wettest: 1.33 inches 1978
Poughkeepsie NY
Records date back to 1931
Normal: High 37 / Low 19
Last Year: High 40 / Low 22 / AvgTemp 31 / Pcpn 0.00
Max Temperature: 63 degrees 1964
Min Temperature: -13 degrees 1980
Lowest High Temperature: 11 degrees 1983
Highest Low Temperature: 41 degrees in 2014
Warmest Average Temperature: 51.5 degrees 2014
Coldest Average Temperature: 2.5 degrees 1980
Wettest: 1.07 inches 1965
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...JPV
NEAR TERM...BGM/JPV
SHORT TERM...JPV
LONG TERM...BGM
AVIATION...BGM/OKeefe
HYDROLOGY...JPV
CLIMATE...
Area Forecast Discussion
National Weather Service Bismarck ND
922 PM CST Sun Dec 22 2019
.UPDATE...
Issued at 921 PM CST Sun Dec 22 2019
Stratus and fog continues its expansion across northwest and north
central North Dakota. The HRRR and RAP have come into better
agreement through their 02 UTC iterations of expanding the fog and
stratus into southwest and south central North Dakota through the
night and into Monday morning. This fits with observed satellite
trends, and a forecast transition to east to southeast upslope
surface winds with low level warm air advection reinforcing the
inversion. Have added a dense fog mention to the HWO, and will
monitor trends for a possible Dense Fog Advisory later tonight.
UPDATE Issued at 534 PM CST Sun Dec 22 2019
Quite a bit of uncertainty tonight regarding fog and stratus
formation. The GOESEast Nighttime Microphysics RGB depicts an
expanding fog and stratus bank across northwest and far north
central North Dakota behind a cold front that has nearly cleared
all of western and central North Dakota as of 2330 UTC. This fog
and stratus bank is not being handled well by most of the rapidly
updating guidance. The RAP has the best depiction, and also is the
most aggressive at expanding the fog and stratus through the
night into Monday morning, which at this points seems plausible
based on observed trends. Thus, have trended towards the 22 UTC
RAP for fog potential within its visibility forecast. A Dense Fog
Advisory is certainly not out of the question.
&&
.SHORT TERM...(This evening through Monday)
Issued at 240 PM CST Sun Dec 22 2019
A cold front will move from the northwest to the southeast
tonight bringing a cooling trend and increasing clouds but we
expect dry weather, to the region. The shallow cool air will
favor some fog formation along with the clouds tonight and Monday
morning.
On Monday, cooler temperatures are forecast, with highs from
around 20 northeast to around 40 southwest. Mainly cloudy skies
are expected Monday as well.
.LONG TERM...(Monday night through Sunday)
Issued at 240 PM CST Sun Dec 22 2019
Cooler, but actually near normal temperatures, are expected to
last through Christmas week. The next chance for snow will be
Christmas afternoon and night, into Thursday, when a shortwave
trough brings a chance for light accumulating snow. GEFS plumes
average liquid remains less than 2 tenths of an inch, but the
individual members remain very dispersive, so this event remains
beyond the forecast horizon.
After the the Christmas snow, the remainder of the forecast period
appears dry with similar temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 914 PM CST Sun Dec 22 2019
IFR/LIFR stratus and freezing fog across northwest and north
central North Dakota as of 0330 UTC is expected to expand into
southwest and south central North Dakota tonight into Monday
morning.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PA
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...PA
Area Forecast Discussion
National Weather Service Houston/Galveston TX
923 PM CST Sun Dec 22 2019
.SHORT TERM [Tonight]...
Only a few minor changes made to forecast...lowering forecast
mins a few degrees NW counties. Kept mention of patchy fog for
those NW areas...including Bryan, College Station, Caldwell,
Madisonville, etc. Both NAM and RAP model soundings for CLL for
example show near surface saturated layer. SREF visibility
guidance and HRRR determinitic vsby fields would also argue for at
least patchy fog up that way...with greater chances and coverage
farther NW beyond the CWA. Had something similar occur Sunday
morning...so certainly reasonable keeping patchy fog mention
there...and will have to evaluate coverage and fog thickness in
the late overnight and around sunrise to see if any stronger
wording may be needed...or perhaps a targetted advisory. Farther
south and east...for areas including the greater Houston and
Galveston areas...not expecting fog...except perhaps very patchy
ground fog...but should not be of any significance. Another cold
night with lows mainly in the lower 40s inland sections.
Reilly
&&
.PREV DISCUSSION /Issued 544 PM CST Sun Dec 22 2019/...
.AVIATION...
VFR. The only caveat will be short-lived northern hub post-
sunrise fog development as temperatures cool to within degree
of their respective dew points. Sky clear and northwest breezes
tomorrow. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 36 67 39 71 45 / 0 0 0 0 0
Houston (IAH) 41 67 44 71 47 / 0 0 0 0 0
Galveston (GLS) 48 64 53 66 57 / 0 0 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until midnight CST tonight
for the following zones: Coastal waters from Freeport to
Matagorda Ship Channel TX out 20 NM...Coastal waters from
High Island to Freeport TX out 20 NM...Waters from Freeport
to Matagorda Ship Channel TX from 20 to 60 NM...Waters from
High Island to Freeport TX from 20 to 60 NM.
&&
$$
Area Forecast Discussion
National Weather Service Wichita KS
613 PM CST Sun Dec 22 2019
.SHORT TERM...(This evening through Wednesday night)
Issued at 343 PM CST Sun Dec 22 2019
A quiet evening is in store across the area as Areas of dense fog
appear likely again develop overnight and continue through
tomorrow morning, with very low visibility possible at times. A
Dense Fog Advisory has been issued across southeast KS, which is
where the greatest confidence for dense dog development is. That
said, RAP soundings indicate the moisture profile is much
shallower than what was realized today. This would bring a small
amount of uncertainty in both the extent and the duration of any
dense fog areas that develop. However, the HREF which has
performed quite well over the last couple of days hits southeast
KS and small areas of east central and south central KS rather
hard. Confidence was not high enough to warrant the advisory
further north and west, but can certainly be expanded if needed.
High temperatures tomorrow continue to be a challenge as the
extent/duration of fog/cloud cover across the area will dictate
how much warming occurs throughout the day tomorrow. Went ahead
and cooled the highs tomorrow given the continued confidence in
another round of low clouds and fog developing, particularly over
portions of southeast KS. As the previous forecaster discussed,
model guidance is quite uncertain indicating highs across the area
of near 40 or as high as the low 60s for areas that don`t see fog
or clear out quickly. Went on the cooler side, yet warmer than
what was reached today, as a shallower moisture profile should
allow clearing a little quicker than today. However that still
keeps southeast KS in the low 50s.
Upper ridging along with southerly sfc flow will continue for the
next couple of days. A ripple in the 700mb will flow will glide
through the area Wednesday into Thursday which will help push a
weak cool frontal boundary through the area however with very
limited moisture, the Christmas Holiday still looks to be dry,
albeit can`t completely rule out a stay rain drop/snowflake.
.LONG TERM...(Thursday through Sunday)
Issued at 343 PM CST Sun Dec 22 2019
A closed mid level low is progged to develop and plunge south
along the West Coast and will move through the dessert Southwest
late next week, bringing widespread precipitation to the area.
There remains some decent disagreements in timing and forward
progression of this feature which will impact precip type and
amounts. However at this time the bulk of the event looks like a
rain event. Changes to the forecast are likely in the extended,
with many days left for models to work on this system.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 613 PM CST Sun Dec 22 2019
Forecast Concern (Major): Potential for (+)FG remains high early-
mid Mon morning.
Most facets of the airmass are essentially unchanged from the past
2 days/nights, but there is 1 difference: A DEEP upper-deck trough
that this evening is situated from the OR Coast to about 300NM off
the CA Coast is ejecting an extensive CS veil ENE across the Srn &
C Rockies. The CS will play the role in all facets of (+)FG
development & duration. For now am `air`ing on the side of caution
by keeping (+)FG assigned to KCNU with IFR vsbys likely at KICT
from about 08Z-14Z. The duration will definitely be watched as the
(+)FG has persisted to almost 18Z the past 2 days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 32 57 36 61 / 0 0 0 0
Hutchinson 30 57 34 60 / 0 0 0 0
Newton 34 57 37 60 / 0 0 0 0
ElDorado 33 57 38 61 / 0 0 0 0
Winfield-KWLD 33 58 38 62 / 0 0 0 0
Russell 29 62 31 57 / 0 0 0 0
Great Bend 29 63 32 60 / 0 0 0 0
Salina 31 57 34 59 / 0 0 0 0
McPherson 31 57 34 59 / 0 0 0 0
Coffeyville 32 54 37 62 / 0 0 0 0
Chanute 33 53 37 61 / 0 0 0 0
Iola 33 53 37 61 / 0 0 0 0
Parsons-KPPF 32 54 37 61 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory from midnight tonight to 10 AM CST Monday for
KSZ070>072-094>096-098>100.
&&
$$
SHORT TERM...KMB
LONG TERM...KMB
AVIATION...EPS
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1001 PM EST Sun Dec 22 2019
.SYNOPSIS...
High pressure will remain in place across the region through
the week, providing for mainly dry and mild conditions.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
GOES-East IR imagery this evening has shown considerably more
enhanced cirrus clouds across our southern CWFA. This moisture,
funneling northeast from a Gulf Coast mid level low, was
located between 300 mb and 250 mb. Latest RAP model indicates
that the combination of some upper divergence from the right
rear quad of an exiting jet, along with some lift from a high
level trof axis, will keep the thicker cirrus longer than
expected. We should, however, see a trend of the cirrus exiting
off to the southeast between 06Z and 12Z as aforementioned high
level trough axis moves southeast as well. Thus skies will
range from mainly clear across the north to mostly cloudy to
cloudy across the south, with a clearing trend expected across
the south later tonight.
Since a surface high is sitting right on top of our area, the
combination of snow melt and added moisture today into the near
surface brings some concern for fog development. However, KILN
sounding shows that moisture to be very shallow with dry air
right above it. So, still thinking any fog will be confined to
the normally foggy locations (river valleys) and very isolated
in nature so as to not place in the public forecast.
Lows should generally range from the mid 20s to the lower 30s
with a few isolated lower 20s possible.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
Quiet weather continues. Deep closed low continues to migrate
across the Gulf Coast states while weak energy much further
north in the northern stream tracks across southeast Canada.
Axis of surface high pressure continues across the heart of the
ILN forecast area. Should again be plenty of sunshine per
forecast soundings. Mixing again will be very limited, and
despite some decent warming up at 925mb /up to +10C/, surface
temperatures will struggle to warm much more than a few degrees
over today`s readings. Generally went widespread mid/upper 50s
in the south, with lower 50s over lingering snowpack in the
north.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Models continue to show a broad ridge in the upper atmosphere
containing anomalous geopotential heights. 500 mb heights of around
5700 meters, coupled with a southerly low level flow around surface
high pressure, will allow much above normal temperatures through the
period. Limited day to day fluctuations will be observed, with highs
in the upper 40s to mid/upper 50s Tuesday increasing to the
low/mid 50s to low 60s Christmas Day, with readings falling
only a few degrees Thursday through Saturday under increasing
clouds and decreasing heights aloft. Sunday may be a few degrees
cooler under a round of modest cold advection on a northwest
low level flow, with forecast highs in the mid 40s to low 50s.
Precipitation threat is absent Tuesday through Thursday due to a
lack of moisture and forcing. Rain chances move in late Friday and
continue through Saturday and Sunday as low pressure and a cold
front move to the Great Lakes. Went below NBM for pops due to model
inconsistency leading to lower than average confidence, especially
considering that the latest ECMWF now shows a return of high
pressure and dry air.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Surface high pressure will remain over the Ohio Valley through
the TAF period. Meanwhile, a weak front will drop southeast
across the Great Lakes on Monday.
For tonight, cirrus shield along and south of the Ohio River
should slowly exit to the southeast. Most locations will see
mainly clear skies. Winds will be light/variable or calm. Some
MVFR mist may form at KDAY/KILN where surface dewpoints are
higher. At KLUK, some local river fog will likely form, bringing
MVFR visibilities with TEMPO LIFR visibilities. All mist/fog
should lift between 13Z and 15Z Monday.
On Monday, FEW-SCT cirrus will drift in from the northwest,
otherwise, clear skies will prevail. Winds will be
light/variable across the south with light southerly winds
across the north.
OUTLOOK...MVFR ceilings possible Thursday into Friday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Binau/Hickman
NEAR TERM...Hickman
SHORT TERM...Binau
LONG TERM...Coniglio
AVIATION...Hickman
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
604 PM EST Sun Dec 22 2019
.UPDATE...
FOR 00Z AVIATION.
&&
.SHORT TERM (Tonight and Tomorrow)...
Current water vapor imagery and RAP upper air analysis indicates a
closed low over Louisiana with moisture surging northward from the
Gulf of Mexico across the Southeastern U.S. At the surface, a low is
centered along the northwestern Gulf of Mexico with a high centered
over the Mid-Atlantic. Low-level winds are generally from the east
to northeast with a downsloping component. Current radar imagery
indicates decent returns as far north as Knoxville. However, the low-
levels are rather dry and not seeing much of this reaching the
ground. Rain is currently being reported at Chattanooga but ceilings
are still in the 6-8 kft range. Additionally, the downsloping is
hindering the northern extent of the precipitation. Overall, it will
continue to take sometime for the low-levels to saturate and for
precipitation to reach the ground.
Models indicate the upper level low will continue to track to the
east throughout the short-term forecast period along the northern
Gulf Coast. Models indicate low to mid-level lift peaking in the 21z-
06z timeframe this evening into tonight. The best lift will be
across the southern tier of counties or so across southeast
Tennessee and southwest North Carolina. The 850 mb easterly winds
will increase during this timeframe as well into the 30-40 kt range
as the surface and upper low continue to deepen. The higher peaks of
southeast Tennessee and southwest North Carolina could see some
gusts approach advisory criteria but will hold off for now. There
will be a sharp gradient in PoPs and rainfall amounts in the short-
term period with storm total amounts in the 1-2 inch range near
Chattanooga with amounts as low as a tenth of an inch in the Tri-
Cities area. Temperatures will be mild tonight with continued warm
advection, cloud cover, and precipitation. Lows will range from the
low to mid 40s for most locations.
Rain chances will begin to taper off from northwest to southeast
late tonight and into Monday. The upper level low is cut-off with
broad ridging across the eastern 2/3rd`s of the CONUS. Therefore,
there will be no real cold air advection as the system drifts to the
southeast on Monday. Skies will eventually clear from northwest to
southeast later in the afternoon with highs in the mid to upper 50s.
The highest temperatures will be across northeast Tennessee and for
the western foothills where low-level easterly flow will continue.
MA
.LONG TERM (Monday night through Sunday)...
Upper low and surface cyclone will be shifting eastward off the
Atlantic Coast of FL on Monday night and Tuesday with upper ridging
increasing across our forecast area. This will result in a mostly
clear sky and warmer than average temperatures across the region.
May have some locally dense valley fog Tuesday night and Wednesday
night with upper subsidence and high pressure at the surface, but
otherwise, quiet weather is expected on Christmas Eve and Christmas
Day. Max temperatures on Christmas Eve and Christmas Day are
forecast to be in the mid 60s across much of the area, around 15 to
20 degrees above normal due to upper ridging magnitude being around
the 90th percentile, but this will still fall short of record highs.
Ridge axis shifts east on Thursday with SW upper level flow and
increasing mid and high level clouds. As moisture increases through
the weekend, rain chances will increase on Saturday and Sunday.
However, large run to run inconsistencies and model to model
differences are resulting in low forecast confidence next weekend.
Global models have widespread ideas on potential phasing, or lack
thereof, of northern stream and southern stream shortwaves which
will impact the magnitude and timing of any associated cyclones.
Based on these uncertainties, maintained only chance PoPs on
Saturday night and Sunday.
JB
&&
.AVIATION...
00Z TAF DISCUSSION.
A NE wind has been supplying dry air in the low levels that have
kept cigs and vis VFR at some sites despite rain. Over the next
few hours, rain intensity is expected to increase, mainly at CHA,
which should lower vis and cigs to potentially IFR conditions. A
downslope wind will continue to affect TYS and TRI, keeping cigs
VFR at those sites, although vis at TYS may drop to MVFR at times
if rain is heavy enough. Rain should taper off across the area
through tomorrow morning, and rising vis/cigs will follow.
DGS
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 46 56 44 67 44 / 100 60 0 0 0
Knoxville McGhee Tyson Airport, TN 45 57 42 64 42 / 90 50 0 0 0
Oak Ridge, TN 44 58 41 64 41 / 80 40 0 0 0
Tri Cities Airport, TN 43 58 39 64 38 / 60 30 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Nashville TN
806 PM CST Sun Dec 22 2019
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
Radar imagery this evening shows light rain continues across the
southeastern two-thirds of Middle Tennessee on the north side of
an upper level low along the Gulf Coast. Rain is expected to
continue through midnight in roughly the same area, but begin to
diminish in coverage and intensity after then with all of the
rain gone by 18Z tomorrow. Have adjusted pops based on radar and
the latest HRRR model. 00Z OHX sounding shows deep, intense
southerly flow through most of the troposphere with an unusually
strong (for the direction) 50 knot southeasterly 850mb jet.
This should keep temperatures roughly steady or with only
a slight decrease overnight, except for the northwest which is
outside of the rain shield and will see decreasing cloud cover by
morning.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR cigs will continue through the TAF period with light rain
affecting BNA/MQY/CSV through 12-14Z before ending. Models appear
to be too aggressive with lowering cigs due to the dry low levels
and have removed MVFR cigs from forecast. Generally light
northeast winds are anticipated through tomorrow.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Shamburger
AVIATION........Shamburger