Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/02/18
Area Forecast Discussion
National Weather Service Denver/Boulder CO
806 PM MDT Sun Jul 1 2018
.UPDATE...
Issued at 759 PM MDT Sun Jul 1 2018
Isold storms will still be possible across the Palmer Divide
through midnight. Otherwise it will be dry across the rest
of the area. Areas of smoke from the Weston Pass fire will
affect the area overnight mainly along and south of I-70.
&&
.SHORT TERM...(This evening through Monday)
Issued at 255 PM MDT Sun Jul 1 2018
Spotty convective cloud development now underway over the Rampart and
Tarryall Ranges and western portions of the Palmer Divide as evident
of GOES-16 visible sat imagery. Now also seeing pyro cumulus topping
the Weston wildfire in west-central Park County. Over the next
couple of hours should see this cloud cover filling in over this
same area and points farther east along the Palmer Divide, as well
as the formation of isolated/widely scattered high based showers
and/or t-storms. At this hour, LAPS and RAP sfc based CAPES running
anywhere from 400-650 j/kg acrs Douglas, Elbert, nrn Lincoln and srn
Arapahoe counties. Models also indicate nearly similar CAPE values
farther north along the I-25 corridor, but convective inhibition
(CIN) is greater in this area. Low-level moisture upsloping the
south side of the Palmer Divide stimulated by strong solar heating
will support strong updraft development along the crest of the
Palmer Divide for the next 3-5 hours. Inverted-V soundings off the
RAP and NAM indicate the potential for strong microburst and outflow
winds. Could see localized gusts to 45 mph. Do no see much in the
way of rainfall as cloud bases will be quite high for the most part.
Will stick with low PoPs from Park County eastward to northern
Lincoln, Douglas and wrn Elbert Counties thru early this evening.
Lastly, with lighter transport flow, smoke emanating from wildfires
in the area may not disperse well. So, hazy/smokey skies will be a
pretty good bet esply east of the mtns.
On Monday...expecting similar conditions, though a shade warmer as
temps aloft continue to warm with a more southwest flow aloft.
Ninety deg temps will be more common on the plains tomorrow with 70s
and 80s in the high country. Sfc winds to start out the day should
be light and variable as per HiRes models, but through the day winds
will increase and become s-swly in direction. At this time, it
appears wind speeds and min RH values will remain below red flag
criteria.
.LONG TERM...(Monday night through Sunday)
Issued at 255 PM MDT Sun Jul 1 2018
Upper trof developing over the northern Great Basin will begin to
shift the flow aloft more southwesterly over Colorado for Monday
night and Tuesday. This will begin to entrain a bit more moisture
over Colorado by Tuesday afternoon and evening with a slight
chance of showers and thunderstorms over most sections. Initially,
there is some higher low level moisture over the far Eastern
plains Monday evening so could trigger a strong to severe storm
there with 2000-3000j/kg of CAPE and dewpoints in the 50s/lower
60s.
The Pacific northwest disturbance shifts out over the northern
high plains Tuesday night and Wednesday which will allow a weak
cold front to move across the northeast plains Tuesday evening
with reinforcing upslope flow on Wednesday. Large dome of high
pressure aloft which covers much of the Mid Atlantic region now,
will also shift westward in the central high plains which will
also help steer moisture into Colorado. Could see a higher
coverage of storms on the 4th of July and continue through
Thursday with decent moisture in place.
The high pressure aloft will continue to shift westward with time
and recenter itself over the southern Great Basin towards Friday
and through the weekend. This will result in drier conditions as
the moisture flow is cutoff and temperatures rebound well back
into the 90s by next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 759 PM MDT Sun Jul 1 2018
A well defined Denver cyclone was in place near DIA as winds
have become northeast on the north side with southeast winds over
southern areas. Eventually this low is supposed to move north
with winds becoming more southerly by 05z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...RPK
SHORT TERM...Baker
LONG TERM...Entrekin
AVIATION...RPK
Area Forecast Discussion
National Weather Service Charleston SC
1008 PM EDT Sun Jul 1 2018
.SYNOPSIS...
Weak high pressure to prevail tonight into early this week. A
surface trough will then move towards the Southeast coast from
the Atlantic by the middle of the week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 10 PM: Last remaining cluster of showers may brush along
the Jenkins County line through 11 PM. The rest of the night
should remain dry over the land zones. Partly clear sky, light
to calm winds, and low to mid 70 dewpoints should support patchy
fog late tonight. Latest HRRR indicated condensation pressure
deficit values less than 10 mbs, generally 10 miles inland of
the beaches. I will keep a mention of patchy fog in the
forecast.
As of 650 PM: Visible satellite indicates very tin and shallow
NE to NW cloud streets across the forecast area. KCLX detected a
small cluster of showers on track to pass over Tattnall County
over the next hour. However, given the radar trends and
conditions of the Cu field, I would expect the convection to
dissipate by 8 PM. I will update the forecast to reduce PoPs
across the SC zones. MOS indicates patchy fog across the inland
zones and portions of the coastal counties. Given the partly
cloudy conditions, light winds, and dewpoints in the low to mid
70s, I will increase the mention of patchy fog across the CWA.
Previous Discussion:
The mid levels consist of a strong ridge over the East Coast.
The ridge will slowly shift eastward tonight. The highest
heights will generally remain far to our north, over the Mid-
Atlantic region. Additionally, a small area of troughing is
located off the west coast of FL, stretching northward towards
the TN Valley. This troughing is forecasted to slowly move to
the west tonight. At the surface, weak troughing will remain
under the aforementioned mid-level trough. Meanwhile, weak high
pressure should hover to our northeast, off the NC coast. PWATs
initially ~2" should decrease to ~1.75" overnight. The
instability is unimpressive for July 1st. SPC Mesoscale Analysis
shows MLCAPEs ranging from 1,000-1,500 J/kg with a few pockets
trying to inch up towards 2,000 J/kg before sunset. CAMs
indicate two areas for precipitation potential into this
evening. The first is over the Charleston Tri-County area, which
generally has been occurring. This convection is getting pushed
inland with the sea breeze. The second area is in association
with a meso-low over the FL Panhandle and the advancement of
convection associated with the Gulf Coast sea breeze. Radar
shows this is occurring and the POPs reflect this in portions of
GA for the next few hours. The severe threat is very low
because DCAPEs are struggling to reach a couple hundred. The
main threat is heavy rain. But with the decent storm motions and
small core sizes, the risk for localized flooding is low. The
convection will dissipate over land this evening and overnight
and then new convection may try to develop over the coastal
waters around daybreak. Additionally, some of the models hint at
the potential for patchy fog or low stratus tonight, especially
in areas that received the most rainfall. But the probabilities
at this point are too low to include in the current forecast.
Lows will average slightly above normal.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Monday and Monday night: The upper ridge will extend to the south
and southwest, encompassing the region. Also noted is an area of NVA
aloft, which should help keep diurnal convection at a minimum. Weak
surface high pressure will extend across the area, with onshore flow
prevailing. Models have been hinting for days that Monday will see
little to no convection and that trend continues. Therefore, rain
chances are only 20 percent, mainly covering the western half of the
forecast area. There is virtually no severe threat and is expected
to be a quiet afternoon with highs in the low 90s away from the
coast. Overnight, the ridge axis will shift inland as an upper low
begins to approach the Southeast coast. A surface trough associated
with this upper low will rotate toward the coast late and could
begin to kick off isolated to scattered showers and thunderstorms
around the Tri-County. Most of the night will be dry and quiet
though with lows in the low to mid 70s.
Tuesday and Tuesday night: The aforementioned upper low will
continue to track westward, removing the influence of the upper
ridge across the area. The surface trough will draw closer and rain
chances increase into the 30-40 percent range, mainly across
southeast South Carolina in the morning and afternoon. Activity
should then progress further to the west and inland into the
evening. The severe threat remains quite low for Tuesday. Overnight,
shower and thunderstorm coverage across the adjacent coastal waters
will increase as the main trough axis nears the Southeast coast.
Wednesday: This is expected to be the most active day of the period.
The upper low will draw near the northeast Florida coast and
shortwave energy will pinwheel around the north side of the low and
into the Georgia/South Carolina coast. Precipitable water values
increase to near 2 inches in the presence of improved forcing, and
models have been consistent in showing broad convective coverage
during the day, so rain chances have been increased into the 60
percent range. Still not a great severe threat, but there will be
the risk of locally heavy rainfall. There should be plenty of cloud
cover with the enhanced coverage so temperatures will be held in the
upper 80s for most areas.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A cutoff upper low will open into an inverted trough as it moves
onshore over the area Thursday, justifying continued higher than
normal POPs. Forecast uncertainly as we head into next weekend
revolves around how quickly ridging builds back into the area,
forcing the trough westward over the Gulf Coast. Have opted for near
normal afternoon storm chances for Friday through Sunday, as weak
ridging looks to dominate locally juxtaposed between the afore
mentioned troughing to our west and another low pressure system that
is progged to remain well off the coast.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
SSE winds will gradually weaken tonight as less than 1 MB
pressure change occurs across SE SC/GA. The partly clear
conditions, light to calm winds, and close dewpoint depressions
may result in a short period of pre-dawn patchy fog. I will
highlight MVFR fog at KCHS with a TEMPO from 10Z-13Z. Otherwise,
conditions should remain VFR and dry.
Extended Aviation Outlook: Overall, VFR conditions will prevail.
However, continued onshore flow will keep a rather maritime airmass
in place, which could result in varying degrees of stratus coverage
late each night or early each morning. Confidence is very low in the
timing and severity of any impacts to terminals.
&&
.MARINE...
Tonight: A weak pressure gradient across the waters is leading
to SE winds generally no higher than 10-12 kt. Winds should
become more southerly and ease a few kt this evening and
overnight. Seas will average 1-2 ft.
Monday through Friday: Weak high pressure across the region on
Monday will give way to a surface trough approaching from the east
by Wednesday. This general pattern will then hold through the end of
the week. Modest onshore flow in the 10-15 knot range will prevail
Monday. Thereafter, the flow will move between northeast and east as
the surface trough meanders around the Southeast coast. Speeds
should top out around 15 knots through the period, with enhancements
along the land/sea interface each afternoon with the sea breeze.
Seas should average 2-3 feet through the period, highest in the mid
to late week time frame.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...NED
SHORT TERM...
LONG TERM...
AVIATION...NED
MARINE...
Area Forecast Discussion
National Weather Service Grand Forks ND
940 PM CDT Sun Jul 1 2018
.UPDATE...
Issued at 938 PM CDT Sun Jul 1 2018
Made additional adjustments to PoPs/Wx/Sky to reflect current
trends. Activity is still holding on, but expectation is still
that weakening and then eventual exit of activity to our east by
06-07Z.
UPDATE Issued at 623 PM CDT Sun Jul 1 2018
Minor adjustments to reflect current radar trends/thunderstorm
coverage, and sky cover. Forecast generally on track. Marginal
storm environment is support development, but so far cells are
remaining sub severe. Still potential for isolated severe threat.
Thoughts are that once the sun goes down and updrafts become
elevated we should see a decrease in intensity with stronger
storms.
&&
.SHORT TERM...(This evening through Monday)
Issued at 339 PM CDT Sun Jul 1 2018
Clouds continue to pull out of northwest Minnesota as a surface
low pressure system lifts eastward into the western Great Lakes.
Sunshine behind that departing cloud mass has allowed for
significant warming and destabilization of the lower atmosphere
across eastern ND and the Red River Valley corridor... ahead of an
approaching midlevel shortwave trof. Showers and thunderstorms
are firing across eastern ND in advance of a surface trof now
located along a Langdon to Jamestown line. The main mid level
circulation is north of the CanAm border... and is lifting into
the Lake Winnipeg region attm. Given the proximity to the mid
level cold pool and stronger surface forcing, isolated strong to
severe convection is more likely nearer the CanAm border,
effectively along and north of the Highway 2 corridor in
northeast ND and far northwest MN through the late afternoon an
early evening.
HRRR guidance is generally an hour or so too fast on timing
storms across the area through this late afternoon into early
evening. Ensemble guidance shows shortwave energy pushing out of
northwest MN from 00 to 03z, so storm activity should diminish
there with sunset. Expect fair skies with light southwest winds
through evening and overnight hours.
Monday should see fair skies and light southwest winds early...
with increasing clouds and an increased risk for thunderstorms
late in the day.
.LONG TERM...(Monday night through Sunday)
Issued at 339 PM CDT Sun Jul 1 2018
Monday night... A warm front will lift across South Dakota during
the day and is expected to move into North Dakota Monday night into
Tuesday increasing chances for thunderstorms. With the introduction
of the low level jet there is potential for strong to severe
thunderstorms. SPC has a day 2 slight risk highlighting the area
around where the MN/ND/SD borders meet for elevated thunderstorms
with the primary threat of hail. The main risk area will be
southeast North Dakota into west central Minnesota.
Tuesday... An active period looks to continue into Tuesday.
Thunderstorms possible Tuesday morning across North Dakota and into
northern Minnesota north of a warm front. In this warm sector
unstable and moist air could allow for strong to severe storms. The
main inhibiting factor looks to be warm mid levels leading to a cap.
This threat continues later in the as well especially after surface
heating provides for a chance to help break the cap. Excessive
rainfall is also a concern for this period as NAEFS R-Climate and
GEFS M-Climate suggest an unusually moist environment with
precipitable water values in the 1.5 to 2.0 inch range.
Precipitable water in this range is near the GEFS M-Climate
maximum in southeast North Dakota Tuesday afternoon and evening.
Independence Day... Looks to be another active day for the
Independence Day holiday. A shortwave trough aloft associated with a
surface cold front looks to continue to provide chances for rain
showers and thunderstorms. Ahead of the cold front it looks to be a
hot and humid day with heat indexes near 90. The timing of the cold
front passage will play a major role in impacts both heat and
thunderstorm related. The cold front is expected to pass in the
afternoon or evening which will bring rain and thunderstorm chances
ahead of it but will cool us down as it passes. Timing of this
passage will be important to many as it could impact holiday
celebrations including fireworks shows near dusk.
Thursday into Sunday... Behind the cold front surface high pressure
moves in leading to a dryer and cooler period for the end of the
work week. Heat and moisture returns to the area for the weekend and
with another cold front passing late Saturday into Sunday rain and
thunder chances return.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 623 PM CDT Sun Jul 1 2018
Isolated to scattered thunderstorms tracking from central ND into
NW MN are producing outflow and erratic winds (occasionally
gusting around 40 mph). When these storms move over a terminal
(which is more likely from KDVL to KGFK to KTVF) MVFR vis with
moderate to heavy rain (and possibly hail) will be possible.
Coverage should decrease and transition east of the region by the
later part of the evening, with VFR conditions then prevailing
through the remaining TAF period.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...DJR
SHORT TERM...Gust
LONG TERM...NC
AVIATION...DJR
Area Forecast Discussion
National Weather Service Goodland KS
850 PM MDT Sun Jul 1 2018
.UPDATE...
Issued at 850 PM MDT Sun Jul 1 2018
Latest 00z model data showing low level moisture currently south
of the Kansas border lifting north into the southwest portion of
the area shortly after midnight around a surface high. This
moisture continues north by sunrise along and just east of the
CO/KS border. It continues to lift northeast through mid and late
morning Monday. There could be some stratus and possibly some fog
also with this feature but latest visibility forecasts arent too
excited about it just yet so limited any fog mention to Greeley
and Wichita counties.
A weather disturbance in the 700-500mb layer currently near the
Pueblo, Colorado area is forecast to merge with the moisture
mentioned above. 2km CAPE approaches 1000 J/KG around 09z with up
to 1500 J/KG by 12z Monday. CIN in this layer is below 20 J/KG.
The latest HRRR breaks out showers and thunderstorms within the
moisture axis and my slight chance pops may need to be raised if
things pan out per model solutions. This seems to match pretty
close to the stronger low level jet winds. Not sure about severe
weather threat but cant completely rule it out.
So for the update have added some slight chance pops for
thunderstorms. Dewpoints will rise and thus temperatures within
the moisture axis so some adjustment to dewpoints, temperatures
and min temperatures were needed.
Will monitor the possibility of adding fog to more areas as the
later model data comes in.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 245 PM MDT Sun Jul 1 2018
Overview: Surface high pressure /subsidence/ in the wake of a
shortwave lifting northeast toward the Upper Great Lakes will
prevail over the Tri-State area this aft/eve. An upper level
trough will amplify over the western CONUS tonight/Monday as
potent shortwave energy digs southeast from British Columbia to
the PAC NW. Southerly return flow will commence over the High
Plains tonight as surface high pressure progresses east of the
region.
Today-Tonight: Dry/cooler conditions are expected to prevail
across the Tri-State area - though isolated convection cannot be
entirely ruled out in eastern Colorado this evening in association
with weak forcing and marginal destabilization attendant low-
level southeasterly /upslope/ flow in the immediate lee of the
Rockies.
Monday-Monday Night: Moderate to strong destabilization is
expected Monday afternoon as southerly return flow advects richer
low-level moisture (17-18C H85 dewpoints) beneath the elevated
mixed layer amidst seasonably strong insolation. Though forcing
will be weak and primarily confined to low-level convergence
invof a lee trough/cyclone in eastern CO, mid-level lapse rates
on the order of 7.5-8.0 C/km suggest a relatively weak cap. As a
result, scattered convection is expected to develop somewhere
invof northeast CO, extreme northwest KS or southwest NE late
Monday afternoon. With the Tri-State area on the S/SE periphery
of the westerlies, deep layer shear will be relatively weak
albeit sufficient for multicellular organization. Some potential
for upscale growth /cold pool consolidation/ will exist given a
seasonably favorable thermodynamic environment -- though
confidence is low. If upscale growth should occur, propagation
would likely be toward the southeast given 20-30 knot southeasterly
low-level flow. Expect a primary severe weather hazard of damaging
wind gusts up to 70-80 mph along with a potential for quarter to
golf ball size hail, with the greatest threat along/north of I-70
between 4 pm and 11 pm MDT.
.LONG TERM...(Tuesday through Sunday)
Issued at 107 PM MDT Sun Jul 1 2018
Not much has changed in the overall pattern for the extended period.
Expect above normal temperatures with isolated to scattered afternoon
showers and thunderstorms for most of the period.
An elongated upper level high height center located over the
southeastern U.S. along with an upper level low height center
located over the Pacific Northwest region will produce predominantly
southwesterly upper level flow over the High Plains through the end of
the week.
On Tuesday and Wednesday (4th of July), A finger of the Subtropic
Jet will be located over parts of the Tri-State Region. This jet
will aid in producing isolated showers and thunderstorms over the
local area.
For the rest of the week, the upper level high will make it way
westward and be located over the Western U.S. by the end of the
period. During its transit westward it will build a strong ridge
over the Central U.S. and into central Canada. At the same time, the
models are showing a major shortwave trough moving within the flow
and over the axis of the building ridge. This trough will continue
to produce isolated to scattered showers and thunderstorms for the
local area through Friday.
Over the weekend, the ridge axis will become extended from the High
Plains and into the Great Lakes Region. This will influence the
local area with dry conditions.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 515 PM MDT Sun Jul 1 2018
KGLD, vfr conditions expected through much of the period.
Southeast winds under 10kts expected from taf issuance through 14z
then increasing through the rest of the day with gusts over 25kts
expected in the 18z-00z timeframe. There are some indications that
stratus and possibly some br/fg could impact the terminal in the
14z-16z timeframe as low level moisture moves in from the south.
Finally, will have to watch for a few showers/elevated
thunderstorms late this evening through early Monday morning with
isolated thunderstorms possible in the mid to late afternoon.
Right now coverage is too spotty to mention in the forecast.
KMCK, vfr conditions expected through the period. A light
southeast wind expected from taf issuance through 19z then
increasing with gusts near 25kts expected for the rest of the taf
period. Will have to watch for the possibility of a few
thunderstorms late tomorrow afternoon. At present time coverage
is too spotty to mention in the forecast.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...99
SHORT TERM...VINCENT
LONG TERM...BW
AVIATION...99
Area Forecast Discussion
National Weather Service Lubbock TX
643 PM CDT Sun Jul 1 2018
.AVIATION...
Slow moving storms currently 40SW-W of LBB have some potential
to impact LBB and PVW later this evening, mainly in the form of
outflows triggering new storms farther east. Will amend for
thunder once this possibility of new growth downstream becomes
more certain. Otherwise, light E winds veering S by Monday
morning with VFR prevailing.
&&
.PREV DISCUSSION... /issued 257 PM CDT Sun Jul 1 2018/
DISCUSSION...
As of 2 pm the cold front had made it through most of the South
Plains and was along a line from Childress to Lamesa. Several short
term models are showing scattered thunderstorms developing late this
afternoon into this evening. The HRRR has the most widespread
coverage starting along the state line and moving east through the
evening. PoPs reflect this and are around 40% for the western South
Plains this afternoon, then more widespread overnight. Dewpoints
ahead of the front are in the mid to upper 60s with mixed layer Cape
around 2500 J/kg. Storms that are able to form could be strong to
severe.
A narrow band of moisture extending along the New Mexico state line
will linger through Tuesday. Have kept a slight mention of rain for
our western counties to account for any showers and thunderstorms
that are able to form. The next chance of rain will be with the wave
that will move west across the Gulf Coast through the week. As with
previous runs, the bulk of the moisture will stay to our south, but
the wave may brush us close enough for some showers and
thunderstorms. Have kept the slight chance of rain for the
southeastern counties starting Thursday night. With the strong ridge
located to our north, we will stay in easterly flow for the later
half of the week. This should help keep highs to seasonal averages,
in the upper 80s to low 90s.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
93