Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/10/23
Area Forecast Discussion
National Weather Service Amarillo TX
615 PM CDT Sun Apr 9 2023
...New AVIATION...
.SHORT TERM ...
(This evening through Monday night)
Issued at 220 PM CDT Sun Apr 9 2023
Morning convection and a small area of ongoing light precip and
clouds has left an area of cooler temps across the eastern TX
Panhandle, however skies have cleared further west along the weak
boundary that extended roughly from Liberal to Dumas and Romero at
2 pm CDT and a CU field had formed along and ahead of this
boundary. Subsidence in the wake of the leading S/WV is certainly
in play. There is additional energy assoc w/ a s/wv coming into
the backside of the first wave from the NW that is going to have
to overcome this, and the thinking is that it will. CU field has
continued to slowly increase and there is some moderate CU and
modest towering CU and even isold weak shra now present. Expect
better convective development to kick in between 20 and 21 UTC
especially from near Perryton to Amarillo as temperatures continue
to warm. These storms will track ESE and highest POPs remain in
the SE 3rd of the area. RAP continue to forecast MLCAPE of
500-1000 J/KG with cap eroding. This combined with effective bulk
shear of near 30 is enough to support a low chance for a severe
storm this aftn and SPC continues to maintain a marginal threat in
SWODY1 for hail slightly over 1" and wind gusts up to around
60 mph. Storms should mostly push out of the region to the SE by
mid evening.
The combination of near saturated low levels, possibly (hopefully)
some wet grounds from rain and light winds with a weak boundary
across the area should lead to some patchy fog mainly across the
southern zones. There could be some lingering clouds, but if skies
clear wouldn`t be shocked to see some dense patches around
sunrise.
Monday will generally be a nice day with highs in the 70s and just
a light north wind behind the boundary. The boundary may stall
across the southeast corner of the area before retreating north
and washing out and this could lead to an isolated storm in the
far SE corner on Monday. CAPE would be similar to today, which
means a strong storm is possible if everything comes together, but
the area is not included in any SVR storm outlook attm given low
probabilities.
Gittinger
&&
.LONG TERM ...
(Tuesday through next Saturday)
Issued at 220 PM CDT Sun Apr 9 2023
Mid level ridging will develop across the area between a cut-off low
near SE TX and the next trough moving in the Pacific NW. The ridge
will get squeezed between the two systems late Wed into Thu.
Approach of the next trough will lead to deepening SFC low
pressure in ERN CO with tightening PGRAD. This should lead to
breezy to windy southerly flow during the mid-week time frame.
Combination of the SRLY winds and mid-upr ridging will lead to
above normal temps through the week.
As the next large scale upper trough moves east across the WRN US,
models agree that a leading S/WV wave will traverse the area on Thu
with decent H7 theta-e ridging along and ahead of it. H85
moisture/wind progs show modest theta-e ridge along and ahead of a
dry line which sharpens through the aftn across the area. The
limiting factor for convection will be SFC dewpoints which may only
reach the mid 40s, but GFS forecast soundings do show some limited
CAPE which becomes uncapped near the dryline. Not surprisingly,
starting to see some models generate precip focused mainly on the
Panhandles along and just ahead of the dry line. It is possible
this leads to relatively dry convection with limited QPF and lots
of virga (given inverted V soundings) and NBM POPs remain below
15 percent. That said, feel a 20 POP is warranted for parts of the
area (especially central zones). IF this isolated convection pans
out, dryish lighting strikes (potential fire starters) and
downbursts would be the main concerns.
Med range models are all over the place with the evolution of the
main trough as if moves east. Recent trends in operational models
has been toward a more progressive system with less energy in the
base of the trough and fewer NBM ensemble members show the closed
low solution than yesterday. Even models with more robust southern
portion of the trough suggest dry air and strong EML will be an
issue for convective development. This would suggest more of a
fire weather system for our area on Friday with a FROPA by
Saturday. That said, modeling has been struggling and the GEM is
still trying to close and cut the system off over the plains. So
we certainly can not rule out anything at this point for Fri into
Sat which means a rain maker and and/or a fire weather maker are
still both on the table UFN despite the NBM POPs decreasing to
below 15 percent for most of the area Fri-Sat.
Gittinger
&&
.AVIATION...
(00Z TAFS)
Issued at 606 PM CDT Sun Apr 9 2023
VFR conditions are expected at KDHT and KGUY through this period.
At KAMA, VFR is expected through around 07z. Radiational fog may
develop in or around the KAMA TAF site, but confidence is not high
enough to reduce conditions below MVFR. Amendments may be needed
if the fog looks to impact the terminal. So, while not in the
current TAF, IFR/LIFR conditions can`t be ruled out at KAMA from
around 07z through about 13z. Afterward, VFR conditions return.
Aside from the first few hours of this TAF period where winds are
in the 10-15kt range, winds will be light and variable for the
remainder of the TAF period.
&&
.FIRE WEATHER...
Issued at 220 PM CDT Sun Apr 9 2023
Increasing southerly winds are expected through mid week and
elevated to critical fire weather conditions are expected
especially in north and NW zones that remained dry today leading
to higher ERC values in those areas. Wed has the most potential
for red flag conditions in the mid week period and if models hold,
Friday will have greatest potential for higher end red flag
conditions. Relatively dry lightning (or minimal rainfall
producing storms) may be a possibility with the dryline Thursday
as well.
&&
.PRELIMINARY POINT TEMPS/POPS...
Amarillo TX 46 77 46 82 / 20 10 0 0
Beaver OK 42 79 43 83 / 10 0 0 0
Boise City OK 40 77 41 83 / 0 0 0 0
Borger TX 46 82 46 85 / 10 10 0 0
Boys Ranch TX 45 79 45 85 / 10 10 0 0
Canyon TX 44 78 44 82 / 20 10 0 0
Clarendon TX 46 77 45 79 / 30 20 0 0
Dalhart TX 39 77 40 83 / 10 0 0 0
Guymon OK 41 78 42 84 / 0 0 0 0
Hereford TX 45 78 44 83 / 20 10 0 0
Lipscomb TX 43 79 44 81 / 20 10 0 0
Pampa TX 45 78 46 81 / 20 10 0 0
Shamrock TX 46 78 45 78 / 30 20 0 0
Wellington TX 46 77 46 79 / 30 20 0 0
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...None.
OK...None.
&&
$$
SHORT TERM...88
LONG TERM....88
AVIATION...52
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
932 PM CDT Sun Apr 9 2023
.UPDATE...
Issued at 929 PM CDT Sun Apr 9 2023
Other than some upper level clouds in the northwest, the satellite
picture this evening looks clear. Blended in current observations
to the going forecast, otherwise no changes needed.
UPDATE Issued at 635 PM CDT Sun Apr 9 2023
Sunny skies and mild temperatures continue over western and
central North Dakota this evening. Temperatures range from the
upper 30s to lower 40s east to the lower 60s in the southwest.
Some patchy fog remains possible tonight, though with little
confidence in location. No changes needed with this update.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 130 PM CDT Sun Apr 9 2023
The main forecast issue in the short term period will be
temperatures.
Currently, a relatively weak pressure pattern is located over
the, forecast area. Skies were partly to mostly sunny with only
some mid and high level clouds.
Tonight and Monday...Look for broad and strong upper level ridging
to continue to build over the Northern Plains. Forecast lows
tonight are expected to be in the low to mid 20s east, to the low
to mid 30s west. On Monday, highs range from the 40s east to lower
70s southwest. A warm front approaches from the west Monday night
with another mild night where temperatures remain above freezing
in many areas. Runoff from melting snow is expected to make it`s
way to the rivers and streams of western North Dakota through
tonight, and spread into central North Dakota as we head into the
very mild early portion of next week. Flooding of low lying areas
will be a risk across western and central North Dakota going
forward.
.LONG TERM...(Monday night through Sunday)
Issued at 130 PM CDT Sun Apr 9 2023
The main forecast issue in the long term period will be temperatures
through mid week, then precipitation chances later in the week.
Monday and Tuesday will to be the warmest days during the entire
forecast period. Tuesday especially looks quite warm. On Tuesday,
the NAEFS SA table indicates 85H temperatures are at or above the
99th percentile across the state Tuesday afternoon. However the
ECMWF EFI shows the potential for extreme warm temperatures
limited to far western and south central ND, indicating that
although the potential for record or near record highs would be
across the state based on temperatures aloft, surface features, or
lack thereof, and especially in this case, snowpack, will have
something to say about our max temperatures early in the week. NBM
ensemble temperatures at Bismarck, Dickinson and Jamestown
continue to show a large envelope of solutions Monday and Tuesday,
positively skewed. Meanwhile across the north, the spread also
remains high, but interestingly the distribution of solutions is
negatively skewed. One potential reason for this is the shortwave
and associated surface low tracking across southern Canada Tuesday.
GEFS Plumes of 2M temperatures and 85H temperatures at Minot and
Williston do show more of a spread, or more low outliers below the
mean on Tuesday. Thus a timing/placement issue with the shortwave
could mean a tendency that forecast highs could be too high
across the north due to the proximity to this feature, and too low
over southern sites.
Just looking over temperatures today, other considerations
include rural areas vs cities/towns and winds or the lack thereof.
Breezy areas and urban areas would seem have more of a tendency
to over perform than rural and protected areas due to less albedo
(cities) and better mixing potential (winds/elevation). A strong
downslope wind or a frontal passage with strong westerly winds
behind it, would be a failure mode where we temperatures
substantially outperform everywhere across the forecast area, but
that doesn`t seem to be the case here. At this time anyway, the
pressure gradient over the forecast area is decent Tuesday, but
certainly not overly strong as the warmest temperatures aloft are
spreading across the forecast area. So, even though temperatures
aloft would support near record or record highs, it looks like
only the far west and south central, where the the snow is gone,
may realize this potential at the surface. Dickinson has a
forecast high of 80 degrees on Tuesday and the record high is 81
set back in 1949. This would of be the only major climate station
to have the potential for a record high on Tuesday. Another
potential failure mode would be low stratus/fog near/over the
snowpack after a couple days of melting today and Monday. Although
this is something to be monitored as we get closer, the latest
RAP shows low level humidities currently not at levels high enough
to sustain widespread stratus. Any patchy fog that could possibly
develop, would likely burn off pretty quickly with daytime
heating.
Precipitation chances enter the forecast by Wednesday. At this time,
any precipitation looks to be light with mainly rain during the
daytime with a rain/snow mix at night and in the early morning.
Temperatures wise, Wednesday will be a transition day and by
Thursday and Friday we drop below mid April normals, which are in
the lower 50s. We won`t be too far off though, with highs mainly
in the upper 30s and 40s Thursday and Friday, with some lower 50s
possible by Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 635 PM CDT Sun Apr 9 2023
Some patchy fog can`t be ruled out early Monday morning, but
overall uncertainty is too high to include at any TAF site. VFR
conditions expected across all sites otherwise.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...AE
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...AE
Area Forecast Discussion
National Weather Service Gray ME
1025 PM EDT Sun Apr 9 2023
.SYNOPSIS...
High pressure gradually shifts southward through and away from
New England through early week with a continued warming trend. A
weak low pressure system crosses Tuesday night into early
Wednesday with a few showers, but otherwise the warm trend will
continue through the week with many locations expected to reach
into the 70s by week`s end. That is, away from the coast where
cooling sea breezes are more likely to moderate the warmth.
Unsettled conditions look to return this weekend.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
1030pm Update...Very minor changes to temp and winds at this
hour. Broad sfc high pressure continues to pass to the south
tonight, with nearest low clouds either crossing into the
western Great Lakes, the Canadian Maritimes, or SE of Nantucket
Shoals.
7pm Update...Just some refinements to temp trends this evening.
Still plenty warm across the interior, but that should quickly
change with light winds and clear sky present. NAMnest and
latest HRRR runs did well with some of this interior heat, but
not quite as warm as obs. Boundary of marine air is continuing
to push inland (as seen on KGYX), but even cooler, more moist
southerly winds associated with this have died down with a very
pleasant evening across the area.
Previous Discussion...
Conditions are pretty comfortable out this afternoon with full
sun and most having temperatures in the lower 50s and fairly
light winds. Along the immediate coast, temps have fallen back
into the 40s thanks to the seabreeze bringing in the chillier
marine air. Going into this evening...with light winds and
mostly clear skies, temperatures will drop pretty quickly
toward/after sunset, and will do so through tonight with good
conditions for radiational cooling continuing. Similar to last
night/this morning, low temperatures are expected to be
primarily in the 20s, except closer to 30 degrees along the
coast, and probably some teens in the northern valleys.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
High pressure will still be well in control on Monday but will
gradually sink south through the day as an upper trough moves across
Ontario and Quebec. This will set up good WAA as the low-level wind
profile becomes west to southwesterly. We`ll have plenty of sunshine
once again amid the very dry airmass, and good mixing to around 850
mb will support high temperatures reaching the low to mid 60s pretty
much areawide, except along the immediate coast, where a seabreeze
is expected to limit highs to the mid-upper 50s.
Skies will start off mostly clear Monday evening, but we`ll see some
increase in cloud cover overnight as the previously mentioned upper
trough approaches, possibly a light shower or snow shower over the
western ME mountains and/or northern NH. The clouds and a slight
increase in low-level moisture will keep temperatures milder than
previous nights with most seeing lows in the 30s.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A warm ridging pattern over the eastern CONUS staves off much
of the active troughing pattern over Canada through the next
several days, yielding a steady warming trend with few if any
chances for precipitation. Warming will allow well-behaved
snowmelt to continue, though continued drying will also lead to
some fire weather concerns (see dedicated section below). The
primary forecast conundrum on the broad scale will be how
strongly the ridge builds with our region on its cusp, while the
smaller- scale conundrum remains the daily influence of the
sea-breeze vs a deeper onshore flow which would negate some of
the warming at least along the coastal plain.
Starting Tuesday... surface high pressure will have sunken
south, occupying a broad area extending from the southern Plains
across to Bermuda. The resulting large scale flow regime allows
a plume of +15-20C t850 to develop over the Plains. Locally,
temperatures aloft will warm to around +4-6C on strengthening
westerly flow. At the same time, low pressure near James Bay
will dive southeastward toward Maritime Canada bringing
increasing cloud cover over northern New England through the day
with light showers crossing the international border during the
afternoon. Strong mixing will keep cloud bases high with dry
air eating away at much of the precip outside of the
mountains... and highs warming into the 60s to low- 70, except
50s toward the international border where more clouds are
expected. Winds out of the west or southwest will pick up on
Tuesday as well... perhaps becoming quite gusty late in the day
as the low`s circulation nears. The front quickly crosses
overnight with very light precipitation amounts in the mountains
and perhaps a few sprinkles downwind toward the Maine coast.
Winds pull around to the northwest behind the front and remain
gusty through Wednesday under partly cloudy skies, with
temperatures warming into the 50s and 60s, to around 70 in
southern areas.
The aforementioned plume of warmth building up the Plains
shifts eastward with the ridge of high pressure, and pushes into
the Northeast behind the shortwave trough. This will allow
winds to slacken and warmth to build over our region through
late week. Slackening flow also yields greater potential for
daily seabreezes Thursday and Friday, which will have
temperatures along the coast hitting daily maximums mostly in
the 50s/60s early before being knocked down by cool maritime
air... meanwhile temperatures will inland will soar into the 60s
and 70s... and even the 80s for southern interior zones. The
ridge slides offshore by around Saturday as low pressure enters
the Great Lakes Region... ushering in an onshore flow regime for
New England. Thus temperatures over Maine and toward the
Seacoast of NH take a dive with increasing clouds. That Great
Lakes low, in whatever state of (dis)organization it is by the
time it tracks toward the East Coast, is the next potential
weather- maker with any semblance of significant precipitation
chances and looks to arrive late in the weekend.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Short Term...VFR at all sites through Monday night. Winds will be
out of the west to southwest on Monday with a seabreeze possible at
PWM and PSM, which would switch winds to ESE/SE at PSM and S/SSE at
PWM.
Long Term...Gusty westerly or southwesterly flow on Tuesday
backs toward a gusty northwesterly wind by Tuesday, to near 30
knots or so potentially with a mix of VFR decks. Brief MVFR CIGs
and SHRA are possible at KHIE during this time, but at this
point look unlikely. VFR prevails through the remainder of the
week with generally light flow and mostly clear skies. Coastal
sites are likely to be impacted by seabreezes turning flow
southerly or southeasterly during afternoons.
&&
.MARINE...
Short Term...Conditions across the waters are expected to remain SCA
levels through Monday night. High pressure will sink southward
allowing winds to be out of the west to southwest tonight through
Monday night, generally 10-15 kt with gusts to around 20 kt.
Long Term...Southwesterly winds on Tuesday may approach small
craft thresholds ahead of a cold front, and again with frontal
passage as winds turn northwesterly however the warm air
running over the cool waters limit this threat to a degree. High
pressure returns to the waters through late week with daily
seabreezes and eventually onshore flow by the weekend.
&&
.FIRE WEATHER...
Dry weather is expected to persist over the next several days
with the exception of a mid-week frontal passage offering a
brief bout of very light showers Tuesday night into Wednesday
across areas that still have snow on the ground. Warm
temperatures are also expected through the next several days,
especially over the interior of New Hampshire and western Maine.
This will allow for continued snow melt and drying of fuels.
In terms of the fire weather forecast, the most likely days of
low afternoon humidity coinciding with breezy/windy conditions
are Tuesday and Wednesday. Conditions should still be quite dry
on Monday with relative humidity values dropping into the teens
and 20s percent in active FDRAs, but without much wind to speak
of. Tuesday and Wednesday may not be quite as dry in terms of
dew points and humidity, however gusty westerly winds before the
aforementioned front on Tuesday turn northwesterly behind the
front on Wednesday with strong mixing and a lack of rainfall
from the front itself.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
NEAR TERM...Combs/Cornwell
SHORT TERM...Combs
LONG TERM...Casey
FIRE WEATHER...Casey
Area Forecast Discussion
National Weather Service Key West FL
1012 PM EDT Sun Apr 9 2023
...New DISCUSSION, MARINE, AVIATION...
.DISCUSSION...
Issued at 1015 PM EDT Sun Apr 9 2023
A frontal boundary advancing through southern Florida coupled
with decent low level moisture and surface heating assisted in
shower development in the Upper Keys and adjacent waters this
afternoon and evening. The convection began over the inland areas
of southern Florida and slowly drifted southeastward. The MRMS
three hour accumulation shows about 1.30 to 1.75 inches of rain
fell in the Florida Bay, while 0.3 to 0.7 inches fell in various
places in the Upper Keys today. The HRRR and CAMs guidance noted
the movement and onset of today`s convection in our local waters
and the Upper Keys. Guidance continues to depict several more
rounds of showers over the next several hours. Rains are currently
advecting through the outer Gulf waters and should reach the
Bayside and Gulf Side waters over the next several hours. Today`s
high temperature in Key West was 86 degrees, and 87 degrees in
Marathon. Today the winds were generally from the northwest at 10
to 15 mph, with gusts up to 20 mph. When the front slides south of
the Florida Keys, breezes will freshen from the northwest as the
pressure gradient tightens between the high to our northwest and
the cold front to the south.
Tonight, The frontal boundary will push near the island chain
either late tonight or tomorrow morning, thus increasing shower
activity for the island chain and the nearshore and offshore
waters of the Florida Keys. KKEY revealed an atmosphere that is
nearly saturated from the surface up to 603 MB. The precipitable
water value on the 00Z was 0.42 inches higher than the 12Z from
early today. The light winds, abundant moisture in the low and mid
levels of the atmosphere, and weak boundaries in the northwest
flow will induce showers periodically over the next 24 hours. The
lack of heating should cause the convection to remain somewhat
shallow today and during the morning on Monday.
&&
.MARINE...
Issued at 1015 PM EDT Sun Apr 9 2023
Small craft should exercise caution due to increasing winds
tonight and tomorrow. Winds have freshened from the northwest due
to an approaching cold front north of the Florida Keys. Winds
will be moderate early tonight and then become moderate to fresh
as the cold front slides through the island chain. The frontal
boundary will linger south of the Florida Straits through Monday
night.
&&
.AVIATION...
(00Z TAFS)
Issued at 1015 PM EDT Sun Apr 9 2023
VFR/sub-VFR conditions will prevail at both island chain terminal
sites through 10/18Z. Winds will be from the north to northeast
at 7 to 12 knots. As the frontal boundary nears, the island chain
winds will increase to 15 knots, with occasional wind gusts up to
20 knots. The frontal boundary will periodically cause showers to
move through the terminal sites tonight and tomorrow. The various
high resolution models note the shower activity. Therefore, VCSH
was put in the EYW and MTH TAFs due to medium confidence.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...TW
Aviation/Nowcasts....TW
Data Acquisition.....KR
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