Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/05/19
Area Forecast Discussion
National Weather Service La Crosse WI
653 PM CDT Fri Oct 4 2019
.SHORT TERM...(This evening through Saturday)
Issued at 222 PM CDT Fri Oct 4 2019
At 2 PM, skies were mostly cloudy across the Upper Mississippi River
Valley. Temperatures ranged from the mid-40s to mid-50s. The latest
RAP continues to show that the low ceilings will scatter out west of
the Mississippi River between 4 PM and 7 PM and 7 PM and 10 PM for
the remainder of the area. While we will be losing the low clouds
temporarily, the mid and high clouds will be quickly moving into the
region ahead of a negatively tilted short wave trough.
The rain associated with this system will move into southeast
Minnesota and northeast Iowa around midnight and reach the
Mississippi River around 3 AM. With precipitable water between 1
and 1.5 inches, the rain could be heavy at times. Rain totals will
range from 1 to 1.5 inches from southeast Minnesota into north-
central Wisconsin and from a half to 1 inch elsewhere. The HREF
indicates that a few locations could see anywhere from 2 to 2.25
inches. Fortunately, this rain will be falling on to areas which
could take in some water, so not anticipating any flash flooding.
While there is not much CAPE, there is some negative EPV and this
may result in scattered storms. None of these storms are expected
to become severe.
On Saturday afternoon, the rain will be gradually ending from the
west. The winds will shift to the southwest and remain in the 15 to
25 mph range. There will be even some gusts up to 30 mph.
.LONG TERM...(Saturday night through Friday)
Issued at 222 PM CDT Fri Oct 4 2019
The shortwave trough quickly pulls to the north and east Saturday
night with clearing skies. However, lingering cyclonic flow aloft as
a secondary trough drops southeast on Sunday/Sunday night may
keep more clouds around across northern WI and perhaps a few
For the first half of next week, a welcome period of dry weather is
in store as high pressure drifts east across the MS Valley. A
gradual warming trend will take place through mid-week as the
surface high shifts east and return flow develops with highs back
into the 60s and possibly 70s in some spots.
Another upper trough will drag a cold front through along with
increased rain chances late in the week, although confidence
remains somewhat low on the evolution of this system. Ensemble
guidance does, however, favor a period of below average temps
behind the front late next week into the weekend with the
potential for the first widespread freeze/frost for the region.
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 652 PM CDT Fri Oct 4 2019
Ceilings at KRST should finally break out of MVFR around 00Z, so set
ceilings to 5k ft at the start of the TAFs. VFR ceilings expected at
both sites this evening, with rain chances moving in overnight ahead
of an approaching surface low. Ceilings gradually lower overnight
becoming MVFR for both KRST and KLSE by Saturday morning. Strong
south to southeast winds expected ahead of a cold front as a
tightened pressure gradient spreads over the area on Saturday.
Wind shear concerns grow by mid morning ahead of the approaching
front. Although it will be breezy at the surface, winds between 45
to 50 knots are expected at 2k ft through morning/early afternoon.
A brief period of IFR ceilings possible at KRST, with KLSE likely
remaining low end MVFR by early afternoon. Rain looks to move out
by the afternoon hours, with perhaps a few vicinity showers
lingering. Kept thunder mention out as instability looks limited.
Ceilings should lift to VFR criteria closer to the end of the TAF
Issued at 320 AM CDT Fri Oct 4 2019
Rivers are rising or high in many locations and some minor
flooding is occurring or forecast. With the additional rainfall up
to around an inch expected Saturday, more rises will occur into
the new week. Each successive rain event without recovery time is
pushing the water system. Remarkably, much of the area is in the
top 5 wettest years on record /125 years of records/...again. Dont
expect the rivers to get down to seasonal normal levels this
Area Forecast Discussion
National Weather Service Columbia SC
1043 PM EDT Fri Oct 4 2019
A cold front will sink southward and into the forecast tonight
bring an end to the recent heat. A few showers or thunderstorms
could accompany the front. The front will slowly move farther
south and west Saturday but cloudiness and some light shower
activity may remain, along with much cooler conditions. Another
front will move into the region late Monday into Tuesday and
provide a chance of showers and isolated thunderstorms, followed
by fair conditions with seasonal temperatures during the middle
to late part of the week.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A backdoor cold front will move into the forecast area tonight.
High pressure behind the front centered in the Great Lakes
Region will push cooler air into the forecast area. Strong
surface convergence will occur near the front but lingering
upper ridging will limit shower and thunderstorm coverage. The
HRRR suggested scattered coverage. The upper ridging and
associated relatively high mid-level temperatures along with the
nocturnal timing should result in weak instability with a
diminished risk of severe thunderstorms. Temperatures are
expected to steadily fall late tonight as a cold air damming
regime develops with northeasterly surface winds and
southeasterly h85 winds resulting in low clouds.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
A backdoor cold front will push southward out the forecast area
Saturday morning. Cool, northerly air will continue to feed
into the forecast area through the day and mostly cloudy skies
will prevent much diurnal heating. Daytime temperatures will
likely be around 25 degrees lower than the previous day. The
NAM model guidance is cooler than most and is likely handling
the cold air damming set up the best. Some erosion of the wedge
is possible across the southern forecast area given that the
parent high is not as strong as a classic CAD event and the
cloud layer is likely too shallow to produce precipitation for
the majority of the day. The central and northern FA should see
highs in the upper 60s to low 70s. The southern portion of the
forecast area is less certain but should be between the low 70s
and low 80s. Mostly cloudy skies should continue overnight
preventing ideal radiational cooling. Overnight lows will be in
the upper 50s to low 60s.
Sunday, the parent high shifts off of the New England coast allowing
for moist, easterly flow over the forecast area. This will help to
erode the wedge conditions and support a chance of rain, with
highest rain chances to the south and east. With the warmer
onshore flow and eroding cloudiness, daytime temperatures will
be warmer. Expect highs in the upper 70s to mid 80s.
.LONG TERM /MONDAY THROUGH FRIDAY/...
An upper-level trough and surface front should move through the
Southeast late Monday into Tuesday. Models have been less
progressive with the front which may slow or stall as it reaches the
Appalachians. Surface high pressure will build into the Northeast
again by Tuesday night and may end up pushing the front through as
another backdoor cold front. Warm advection ahead of the front and
the frontal passage itself will support a chance of showers and
thunderstorms from Monday through Tuesday night. Though chances are
low (generally 30% or less) given a still relatively dry air mass
and mid-level ridging. Fair conditions and seasonal temperatures
are expected behind the front for Wednesday through Friday.
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions lowering to MVFR for much of the period.
Cold front currently across the northern Midlands and will move
into the terminals over the next couple of hours then south of
the area around daybreak. WSR-88D imagery shows a few showers
and thunderstorms in far southeastern NC and continue to expect
scattered showers around the terminals through daybreak.
Confidence in timing and impacts to specific terminals too low
to include attm so remain with VCSH at all sites. Behind the
front winds will remain northeasterly with MVFR cigs persisting
through mid to late afternoon Saturday. VFR conditions will
return from 19z through the end of the period.
EXTENDED AVIATION OUTLOOK...Early morning fog or stratus and
associated restrictions possible through Tuesday. Restrictions
possible in mainly diurnal convection Monday and Tuesday.
Augusta Regional Airport (AGS) daily high temperature record:
10/4: 101 set 10/4/19. Previous date record was 97 degrees set
The high of 101 was also a record for the month of October
surpassing yesterday, 10/3/19, when the high was 100. Before
yesterday, the record for the month was 97 set on October 4th,
5th, and 6th in 1954.
The daily high temperature record has now been either tied or
broken on nine of the past ten days in Augusta beginning 9/25.
Daily temperature records in the Augusta Area date back to 1873.
Columbia Metro Airport (CAE) daily high temperature record:
10/4: 100 set 10/4/19. Previous date record was 97 degrees set
Five high temperature records have occurred during the past
nine days in Columbia. Daily temperature records in the
Columbia Area date back to 1887.
Columbia`s record high for the month of October is 101 set
October 5th in 1954.
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1044 PM EDT Fri Oct 4 2019
High pressure will keep dry weather over the area through
Saturday. A cold front will bring rain Sunday into Monday. High
pressure and dry air are forecast to return for Tuesday and
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Area of cirrus that is moving across the northern counties is
beginning to break up. Expect this to continue and the skies to
be mostly clear after midnight.
Lows will range from the mid and upper 40s with some lower 40s
in outlying locations.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Dry weather will continue Saturday as the high moves off the New
England coast. Expect temperatures to warm back into the 70s as
warm advection rides on a veering east to southeast flow behind
Slow moving frontal system will be moving toward the area
Saturday night. There will be a chance of showers after midnight
as the air column moistens under increasing lift and convergence
aloft. Under the blanket of mostly cloudy skies, lows will be in
the upper 50s to lower 60s.
.LONG TERM /SUNDAY THROUGH FRIDAY/...
A cold front will be making its way slowly southeast into our region
on Sunday. There will be the likelihood of showers along the frontal
boundary with a chance elsewhere. There could be enough instability
for a rumble of thunder across the southeast zones during the
afternoon. Clouds will thicken with highs ranging from the lower 70s
northwest to the mid/upper 70s elsewhere.
A large scale mid level trough will dig southeast into the Great
Lakes and Ohio Valley Sunday night. Models continue to show that
upper divergence will develop in the RR quad of an upper level jet
(located on the east side of the mid level trough). This will induce
airmass evacuation, which will in turn allow a low level jet to
respond, which will impinge along the slow moving frontal boundary.
This will result in moist ascent along and over the boundary, which
should bring categorical PoPs to locations along and southeast of
the I-71 corridor, with probabilities decreasing toward west central
Ohio. Model blends indicate rainfall totals from a half inch near
the I-71 corridor to near 1.50 inches across the southeast zones.
This will be beneficial given the dry conditions and the onset of
drought conditions across the region. Lows will fall into the lower
to mid 50s.
On Monday, the cold front will continue southeast. Precipitation
will taper off from west to east as the upper level jet moves away
and the mid level trough axis moves overhead. An additional half
inch of rain is expected over the southeast half of the forecast
area before precipitation ends, bringing 1 to 2 inches of rain for
locations along and southeast of the I-71 corridor. Clouds will
slowly decrease from the northwest. It will be cooler with the
coolest reading expected across the southeast. Highs will range from
the lower to mid 60s.
As the overall mean mid level trough moves east Monday night, skies
will clear as drier and cooler air moves in from the west. Lows will
range from the lower to mid 40s.
Dry with sunny weather is expected on Tuesday as the surface high
traverses the Great Lakes and Ohio Valley. Highs will range from the
mid to upper 60s.
A mid level ridge is forecast to build near or just east of the
Great Lakes and Ohio Valley Tuesday night into Thursday in response
to large scale mid level troughing digging into the intermountain
west and the Great Plains. The center of surface high pressure will
gradually move off to the north and east. Skies will be mostly
clear/mostly sunny Tuesday night into Wednesday with a gradual
increase in clouds Wednesday nigh into Thursday. It should remain
dry. Cool lows in the lower to mid 40s Wednesday should give way to
lower to mid 70s Wednesday and Thursday.
There remains much uncertainty in the timing of the large scale mid
level trough as it moves east toward our region Friday into next
weekend. Much of this depends on jet energy digging into the back
side of the trough and whether a closed low forms as a result. This
will have timing implications with the next frontal boundary. Will
forecast partly cloudy skies for the end of the extend with low
chances for showers for now as we head into next Friday.
Temperatures will be a little above normal for early to mid October.
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Broken VFR stratocu continues to affect CMH/LCK due to cold air
aloft associated with departing high pressure. Expect the sc to
go scattered in the next few hours. Meanwhile bkn-sct cirrus is
racing east across northern Indiana into northern Ohio. Some
broken cirrus ceilings will also be possible for the first
quarter of the taf period. After 06Z mostly clear skies are
The center of the high will be over New England with a H5 ridge
over the Ohio Valley at 12Z Saturday. During the day Saturday,
the ridge will work into the Appalachians and upper level
moisture will begin to increase. Winds will veer from the
northeast tonight to the southeast on Saturday, before becoming
south after 00Z Sunday.
OUTLOOK...MVFR ceilings and visibilities are possible on Sunday
Area Forecast Discussion
National Weather Service Little Rock AR
648 PM CDT Fri Oct 4 2019
SHRA continue across southwest AR along and adjacent to a stalled
out frontal boundary. Precipitation is expected to impact KADF
and KHOT for the next several hours before dissipating. Prevailing
VFR conditions are being observed across all terminals attm and
expected to persist through the TAF cycle for all locations
except KADF and KHOT, where heavy rainfall from today is expected
to lead to low clouds and reduced visibilities to MVFR/IFR by
sunrise. VFR conditions should quickly return after sunrise on
.PREV DISCUSSION...(ISSUED 237 PM CDT Fri Oct 4 2019)
Short Term...Tonight thru Sunday...
Cold front has pushed thru the state, and a weak surface trof
extended over portions of southwest AR this afternoon. With a ridge
flattening out across the southeast, warm and moist air was being
pumped up over the surface front and was resulting in scattered
convection across southwest Arkansas. Some of this convection has
been training over the same areas along the I-30 corridor for hours,
and prompted the issuance of a flash flood warning. Several radar
rainfall estimates in some areas are over 6-7 inches, and the
heaviest rain is falling in an area where we have a lack of ground-
based observations. Convection has been rather shallow, and cloud-
top temperatures have not been excessively cold, so I suspect these
radar estimates are too high.
I should point out that most models have been clueless about the
ongoing convection today. Even the short-term models like the HRRR
have been trying to kill all the convection after an hour or two,
and this keeps repeating from run to run. No surprise, but the
models show little to no POPs after 00Z, but I have manually
augmented POPs in the southwest this evening, and tapered these off
Looking ahead, the ridge will continue to flatten out during the
remainder of the short term, and a second cold front will push down
into the area late tomorrow into Sunday, bringing additional
rainfall. POPs are being introduced in the NW zones tomorrow
afternoon, and should overspread much of northern AR Saturday
night. By Sunday, rain chances will be over 50 percent for much of
Extended Term...Sunday Night thru Friday Night...
The period begins with a long-wave trough tracking east through the
northern half of the U.S., with positive vorticity advection and
high winds speeds aloft. The forcing aloft supports a surface cold
front, which will have already entered the NW corner of the state by
late Sunday. The front will track SE and bring rain chances
throughout the day Monday, with cooler temperatures through the rest
of the week. High and low temperatures next week will be slightly
Weak upper level ridging will follow and become more
zonal through mid week until early Thursday, when a deep upper
trough approaches from the west, with strong upper level forcing and
winds. This wave will support another surface cold front, forecast
to enter the state from the west early Friday, bringing another
round of rain chances (through Saturday morning) and colder than
average temperatures behind the boundary.