Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/04/17
Area Forecast Discussion
National Weather Service Cleveland OH
949 PM EDT Wed May 3 2017
.SYNOPSIS...
Low pressure will develop over the lower Mississippi Valley
then occlude and move northeast to the Ohio Valley on Thursday
night. The low will slowly drift to the eastern Great Lakes
through the end of the week.
&&
.NEAR TERM /THROUGH THURSDAY/...
Update...Updated pops. Followed HRRR which shows precip
spreading east across the southern/swrn tier of counties before
lifting north. This agrees with the current radar trends as
well.
Original...Digging upper wave over the southern Plains will
cutoff and track into the mid Mississippi valley tonight. Area
of frontogenesis will lift northeastward across Indiana into
northwest Ohio tonight ahead of the low, associated with coupled
upper jet structure/divergence aloft. Cloud cover will increase
from southwest to northeast through the night with precip
expected to overspread the area after 06Z. The heaviest rainfall
should remain just west of the forecast area overnight.
Increased pops to categorical across the west after 09Z, with
likely pops eastward through much of the area.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
Upper low will continue to deepen and spin east through the Tennessee
valley Thursday and Thursday night, as surface cyclone deepens and
translates northeast along the Ohio valley. Coupled jet structure
will remain in place across the southern Great Lakes Thursday before
slowly translating eastward. Deformation axis will be the focus for
heavy rainfall across the area during this time frame.
Models have come into decent agreement with respect to placement of
heaviest rainfall/deformation axis. Heaviest rainfall should remain
west of the forecast area during much of the day Thursday, although
rain showers will be present across the area. Deformation axis is
expected to sink southeastward into the Findlay to Toledo areas by
Thursday evening and will translate eastward after that. Thinking
the heaviest rainfall will occur across the northwest Ohio counties
from 21Z Thursday through 09Z Friday. Rainfall intensity is expected
to taper a bit across the area on Friday as best deformation skirts
north of the area. Surface low will track northeast across western
PA Friday with renewed frontogenesis/focus for precip as northern
stream wave digs south into the Great Lakes as phases with the
cutoff low. This will provide renewed moderate rainfall potential to
the eastern half of the forecast area Friday evening and overnight.
Storm total rainfall from late tonight until Saturday morning
remains largely unchanged from previous forecast, with generally 2
to 3+ inches across northwest Ohio tapering to 1 to 1.5 inches
across the eastern half of the area, with around 2 inches along the
I-71 corridor splitting the difference. Will hold off on a Flood
Watch with this issuance, as the heavier rainfall may be more than
24 hours out from affect the local forecast area. Heavier rainfall
totals certainly possible across the western half of the area if the
deformation axis shifts slightly eastward.
Rain shower activity will continue across northeast Ohio and NW PA
Saturday as the surface low pivots around southern Ontario as yet
another piece of northern stream energy digs south through the
eastern Great Lakes cutoff low. Kept with likely/cat pops for these
area Saturday with a diminishing trend in pops Saturday night as the
low finally beings to move away from the area.
Temperatures remain largely unchanged, unfortunately, and will be
downright miserable for early May for parts of the area Friday and
Saturday. Northeast flow off the lake will keep highs near 50 or
even remaining in the upper 40s downstream of the lake in NW OH.
Highs in the low 50s across NE OH and upper 40s in NW PA expected
Saturday.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The persistent upper low will have lifted into eastern Ontario at
the start of the period with gradual improvement in the weather. Any
lingering showers over northwest PA should exit Sunday morning as
unseasonably cool high pressure gradually builds into the region.
Frost will be a concern Sunday night especially in low lying regions
away from the lake such as near Wooster, Marion, Jefferson and
Youngstown.
High pressure will move east of the region by Tuesday as a short
wave in the northwest flow aloft moves through the region. Models
show timing differences with the GFS faster than the ECMWF. By the
middle of next week the models diverge somewhat and forecast
confidence decreases. The jet stream has evolved with cut off lows
with the possibility of a repeat of the short term weather again by
next weekend which is beyond this forecast period.
&&
.AVIATION /00Z Thursday THROUGH Monday/...
VFR through about 10Z when MVFR and IFR will be on the doorstep
spreading across west-central OH. Low pressure will move from
the lower Mississippi Valley, deepening and stalling across
western KY for the day Thursday. Widespread rain will overspread
northwest OH quickly in the morning with more scattered showers
across the far eastern terminals. Have delayed the onset of the
lower ceilings, but when they arrive they will not be going
anywhere anytime soon for TOL/FDY. CLE/MFD will be on the edge
of MVFR/VFR and remaining terminals may very well stay VFR
through 00Z Friday with a drying downslope ESE flow. Trough will
set up across the area...approx from MFD to CLE to ERI with a
stiff northeast flow north of that line and east-southeast flow
south. Low level wind shear may become an issue for MFD/CAK late
Thursday afternoon as strong southerly low level jet gets going.
OUTLOOK...Non-VFR likely Thursday night through much of
Saturday. VFR returning from west to east Sunday.
&&
.MARINE...
Tranquil conditions on Lake Erie will be short lived as the next
storm system over the Mississippi Valley rapidly approaches the
region tonight and tracks northeastward and remains to the south of
the lake into Saturday. Light winds early this evening will become
east to northeastly by morning and increase to near 20 knots over
the western basin. East to northeast winds will increase to 15-25
knots across the lake with the highest winds expected from the
western basin out into the central basin but away from the Ohio
shore east of Avon Point. Will likely need a small craft advisory
west of Avon Point starting tomorrow morning and across the entire
southern lakeshore by later Thursday night.
As the low pressure system shifts by to the south of the
lake...winds will back to north and northwest Friday and Friday
night. Winds will remain out of the northwest through much of the
weekend. Wind speeds of 15-25 knots can be expected with diminishing
winds on Sunday.
Light winds are expected over the lake early next week.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...Flood Watch from 8 AM EDT Thursday through late Friday night
for OHZ003-006>010-017>019-027-028-036.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Greenawalt
NEAR TERM...Greenawalt/TK
SHORT TERM...Greenawalt
LONG TERM...LaPlante
AVIATION...Oudeman
MARINE...LaPlante
Area Forecast Discussion
National Weather Service Dodge City KS
610 PM CDT Wed May 3 2017
...Updated Aviation...
.SHORT TERM...(This afternoon through Thursday)
Issued at 1225 PM CDT Wed May 3 2017
Scattered showers and isolated thunderstorms are expected to
redevelop this afternoon. Cold 500 mb trough axis over NE Colorado
at midday will swing through SW KS late this afternoon and early
evening. Models continue to destabilize the atmosphere this
afternoon, as 500 mb temperatures drop to -25C and interact with
early May insolation. NAM/GFS/CAM solutions all suggest scattered
shower coverage will be highest across the eastern 1/2 of the CWA
into early evening. With CAPE near 500 J/kg and lifted indices
falling to -3C, the strongest cells may produce pea-sized hail,
but nothing more than that. North winds will ramp up late this
afternoon and early evening as the trough axis passes, gusting
30-35 mph at times.
Showers will linger for a few hours this evening across the
eastern zones as shown by the latest HRRR runs, followed by a
clearing sky overnight. Surface high pressure near the Nebraska
panhandle at 7 pm this evening will build southward overnight,
with a 1025 mb high over the far western zones around sunrise
Thursday. A light NW wind is expected to prevent optimal
radiational cooling, but that said, lower to mid 30s are expected
across the western zones. Maintained the inherited frost advisory
for the western zones Thursday morning. Lows tonight in the upper
30s to lower 40s elsewhere.
Thursday...Sunny and warmer. Quiet weather with few if any clouds,
as SW KS is sandwiched between a strong cutoff low near Memphis
and a strong ridge near Phoenix. North/northwest winds will remain
breezy after 10 am, averaging 15-25 mph. Highs in the 60s.
.LONG TERM...(Thursday night through Wednesday)
Issued at 145 PM CDT Wed May 3 2017
An extended period of dry weather is expected to prevail through
Tuesday. Dry NW flow continues Friday, and the high pressure ridge
axis phases overhead Saturday evening, delivering beautiful spring
weather with few clouds and light winds. Sunday, with ridge axis
across central Kansas, lee trough/dryline will establish across
the high plains of Colorado/New Mexico. Slow-moving cutoff low is
expected to reside in central California Sunday afternoon.
Shortwaves rotating around the eastern periphery of this cyclone
are expected to initiate diurnal thunderstorms along the lee
trough/dryline. The odds of any activity managing to sneak into
far SW Kansas are very low, and kept forecast for Sunday dry (pop
grids < 15%). Kept the dry forecast going Monday and Tuesday as
well; with the closed low in the Desert SW making little
appreciable progress eastward, forcing for ascent and diurnal
thunderstorms are expected to remain just west of SW Kansas.
Finally, medium range model consensus is for the upper low to
eject out onto the plains next Wednesday. Although there are some
strength and placement issues in the models (typical of a 7 day
forecast), pattern recognition and climatology suggests severe
thunderstorms will be possible in SW KS next Wednesday.
Temperatures will show a warming trend, adding a few degrees each
day, Friday through Sunday. The warmest days are expected to be
Sunday and Monday, when 80s will be common each afternoon.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 546 PM CDT Wed May 3 2017
Isolated showers and thunderstorms will gradually end through the
area around 02Z and the skies will clear out quickly after 06Z.
Winds may pick up a bit tomorrow afternoon with gusts up to 25 kts
@ 350.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 67 40 73 / 30 0 0 0
GCK 36 67 40 73 / 20 0 0 0
EHA 36 68 44 75 / 20 0 0 0
LBL 39 68 42 75 / 20 0 0 0
HYS 42 67 42 73 / 40 10 0 0
P28 43 69 43 73 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 1 AM CDT /midnight MDT/ to 9 AM CDT /8 AM
MDT/ Thursday for KSZ043-061-062-074-075-084.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Tatro
Area Forecast Discussion
National Weather Service Jacksonville FL
1032 PM EDT Wed May 3 2017
...Strong to Isolated Severe Thunderstorms Possible on Thursday
and Thursday Night...
.UPDATE...
Late evening surface analysis depicts organizing low pressure
(1003 millibars) centered near the Arklatex region, with warm
frontogenesis occurring along the northern Gulf coast and a cold
front pushing eastward through eastern Texas. Aloft...a trough
digging from the Plains states into the lower Mississippi Valley
is about to take on a more neutral tilt as a potent shortwave
trough dives south-southeastward from the Texas and Oklahoma
panhandle region. A large area of convection associated with this
developing storm system cover the lower Mississippi Valley and
eastern Texas, with showers weakening well ahead of this system
over the Florida panhandle and northeastern Gulf of Mexico. High
clouds will continue to gradually increase from the west during
the overnight hours, with strengthening southeasterly winds in the
boundary layer precluding fog development. Some pockets of lower
stratus may move into the Suwannee Valley and north central
Florida during the predawn hours, but fog is not anticipated.
Strengthening southeasterly boundary layer winds will keep smoke
from the ongoing West Mims wildfire on a west to northwest
trajectory overnight, with areas from Needmore and Fargo to
Homerville and possibly Folkston possibly experiencing reductions
in visibilities to 3-5 miles. Warm air advection developing ahead
of this storm system will keep lows generally around 60 inland and
the upper 60s in coastal locations.
Global and short-term, high resolution model guidance continue to
indicate increasing chances of some beneficial rainfall on
Thursday, most likely occurring in two distinct rounds ahead of an
approaching strong cold front. The 00Z NAM and 01Z HRRR indicate
that activity currently over the lower Mississippi Valley will
organize into a squall line overnight, with this line approaching
our western counties from the west during the mid-morning hours on
Thursday. This line is likely going to weaken as it progresses
eastward through our region, but a few strong thunderstorms
containing wind gusts of 45-65 mph cannot be ruled out around the
noon hour in the Suwannee Valley and inland southeast Georgia.
Given the increasing agreement in the global and short term models
in this line traversing our region tomorrow, we increased rain
chances into the categorical range for most locations tomorrow,
with some potential for enhancement and a few strong storms along
a pinned seabreeze boundary in the coastal counties during the
afternoon hours. Instability should increase over the western
counties during the late afternoon and evening hours ahead of the
front, aided by a low level southwesterly jet of 40-55 knots above
950 millibars (1500 feet). We reduced highs for Thursday slightly
given the earlier start to convection, with highs around 80
southeast GA and the Suwannee Valley, with mid/upper 80s
elsewhere.
The Storm Prediction Center has placed a slight risk for severe
thunderstorm development over inland southeast Georgia, and it
appears as if this threat may be higher during the evening hours
rather than the daylight hours tomorrow as the hi- res models
unanimously weaken the squall line approaching from the west.
Convection along the front may again organize into a squall line
during the overnight hours tomorrow night, with this activity
traversing the rest of our area during the overnight hours into
the predawn hours on Friday. Rainfall totals from this event are
looking a little more beneficial, with most areas forecast to
receive one half inch to one inch, with locally higher totals
possible.
&&
.AVIATION...
VFR conditions will prevail at the regional terminals through at
least 15Z Thursday. Southeasterly winds from around 500 feet up to
5000 feet will strengthen to 20-25 knots after 06Z tonight, with
surface winds remaining around 5 knots or less through 11Z. South
southeasterly surface winds will quickly increase to 15-20 knots
with higher gusts beginning around 14Z. A squall line of showers
and thunderstorms will move across the terminals from west to east
from around 16Z through 22Z, with brief reductions in visibility
possible as activity crosses the terminals. We placed a PROB30
group at each terminal after 15Z/16Z for this possibility, along
with potential westerly wind gusts up to 35 knots as this line
moves through. Additional thunderstorm activity is possible from
Thursday evening through the overnight hours as a strong cold
front moves through our region.
&&
.MARINE...
Southeasterly winds will begin to strengthen during the predawn
hours on Thursday, but speeds and seas will remain below caution
levels through at least the mid-morning hours. Small Craft
Advisory conditions are expected towards noon, as winds slowly
turn to a more southerly direction ahead of an approaching squall
line of strong to severe thunderstorms. This line should enter the
coastal waters during the afternoon hours, with additional
activity possible through around sunrise on Friday along a strong
cold front. Seas in the offshore waters will build to 6-8 feet by
Thursday evening, with near shore seas building to 4-6 feet. This
front will cross our coastal waters during the early morning
hours on Friday, with strong offshore winds expected to persist
from Friday through Saturday. Small Craft Advisory conditions will
persist in the offshore waters through Friday night, with caution
conditions expected on Saturday. Offshore winds will fall back to
caution levels in the near shore waters on Friday, with a brief
period of SCA possible Friday night, with caution level wind
speeds expected Saturday. High pressure will then build into our
region from the west late this weekend, with winds and seas
falling below caution levels by Saturday evening.
Rip Currents: Moderate risk to continue through Thursday as a
strong longshore current develops at area beaches, with
strengthening southeasterly winds anticipated during the morning
hours.
&&
.FIRE WEATHER...
South southeasterly winds will strengthen shortly after sunrise on
Thursday, with sustained surface speeds increasing to 15-25 mph by
the mid to late morning hours. These winds will keep humidity
values well above critical thresholds, but dispersion values will
be high region-wide from late morning through sunset. A couple of
rounds of showers and thunderstorms are expected on Thursday and
Thursday night, with most locations expected to receive one half
inch to one inch of rainfall. A few strong and isolated severe
thunderstorms will be possible, beginning in our western counties
during the mid to late morning hours. The front will cross our
region during the predawn and early morning hours on Friday, with
breezy west/southwest winds expected on Friday along with high
dispersion values.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 60 80 56 74 / 0 80 50 10
SSI 69 80 61 77 / 0 70 70 10
JAX 61 84 60 76 / 0 80 70 10
SGJ 68 84 62 79 / 0 80 60 20
GNV 62 87 60 75 / 0 60 70 10
OCF 64 88 62 77 / 0 50 60 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...Small Craft Advisory from 10 AM Thursday to 10 AM EDT Friday for
Waters from Altamaha Sound GA to Fernandina Beach FL from
20 to 60 NM-Waters from Fernandina Beach to St. Augustine
FL from 20 to 60 NM-Waters from St. Augustine to Flagler
Beach FL from 20 to 60 NM.
Small Craft Advisory from 10 AM Thursday to 3 AM EDT Friday for
Coastal waters from Altamaha Sound to Fernandina Beach FL
out 20 NM-Coastal waters from Fernandina Beach to St.
Augustine FL out 20 NM-Coastal waters from St. Augustine to
Flagler Beach FL out 20 NM.
&&
$$
Nelson/Hess/Corless
Area Forecast Discussion
National Weather Service Lubbock TX
620 PM CDT Wed May 3 2017
.AVIATION...
Aside from a thunderstorm which is moving out of the CDS terminal
area, VFR conditions are expected over the next 24 hours.
There is a low risk of additional showers mainly at KCDS and KPVW
through 04Z
&&
.PREV DISCUSSION... /issued 342 PM CDT Wed May 3 2017/
DISCUSSION...
Gusty wind speeds continue across the area this afternoon although
speeds have come down from what we have seen this morning. Biggest
question for the remainder of this afternoon into tonight is
whether there will be any showers moving into the northern half of
the forecast area. The last several runs of the HRRR, some of the
RAP runs, and 12Z run of the TTUWRF all have isolated to scattered
precipitation developing across the northern half of the forecast
area while the rest of the operational models keep us dry. Based
on both visible and water vapor satellite loops, it looks like
enough dry air will be in place across the region to keep any
precipitation from developing. Showers and a few thunderstorms
across the TX/OK Panhandles drifting south towards the area may
make it into the northern zones but it will be difficult to get
any precipitation to the ground in the dry air.
After the storms dissipate, we should have a quiet night lead into
a quiet weekend weather-wise as a ridge builds across the region.
Surface flow will return to the south to southeast and combined
with the building heights under the ridge will bump high
temperatures back into the mid to upper 80s for the Caprock and
upper 80s to some lower 90s for the Rolling Plains. Through this
same time period, models continue to deepen a trough into a strong
closed low across the West Coast and start to swing this system
east by Monday. This should mark the start of a more active period
for storms for the first part of next week.
There are still considerable differences in timing and strength of
this next storm system but it does look like low-level Gulf
Moisture will stream back into the region Sunday night into Monday
morning as a strong low-level jet develops. The dryline will
become established across eastern New Mexico and both the GFS and
ECMWF hint at a series of weak shortwave to swing out ahead of the
main low. It remains way too early to have a good handle on when
and where storms may develop but this pattern typically results in
storms developing across eastern New Mexico in the late afternoon,
and then a few of those drifting east into the western part of the
forecast area. Coverage is expected to be best in the afternoon
and evening hours so cut back PoPs in the morning for Monday and
Tuesday. Shear profiles plus the presence of an elevated mixed
layer may allow for a few severe storms, especially if the
directional shear profiles improve from what is currently in the
forecast. Wednesday remains the day of biggest uncertainties as
the models kick the dryline east of the area at some point during
the day but differ on the timing of this as well as the movement
of the closed low. The GFS is now the faster of the two extended
range models and much stronger than the ECMWF with the closed low.
Precipitation chances may need to be extended into Thursday and
possibly Friday IF enough moisture remains behind the departing
system and as a cold front moves across the area.
After the warm temperatures this weekend, the diurnal spread in
temperatures will decrease as increasing moisture helps to
moderate highs back into the upper 70s to lower 80s. Low temps
will also bump back up into the 50s and lower 60s across the
forecast area as the dryline sloshes west in the overnight hours.
Jordan
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
99/99/26
Area Forecast Discussion
National Weather Service Nashville TN
811 PM CDT Wed May 3 2017
.DISCUSSION...
Surface map this evening shows a low centered near Shreveport with
a warm front extending northeastward from the low right up
through the northwest corner of Middle Tennessee. At this time,
the deepest moisture is still upstream, but already we`re seeing
isolated cells pop up west of I-65. The evening sounding from OHX
does show a surface-based CAPE of nearly 800 J/kg and a lifted
index of -5, so the instability is there, even if the moisture is
somewhat lacking (precipitable water only 0.90 inches). Given that
the winds throughout the mid-layer are from the southwest at
30-35 kts, a decent amount of moisture advection can be expected
during the next few hours. The HRRR does show more widespread
activity developing over Middle Tennessee late this evening and
extending through the overnight period. The SPC keeps us in a
general thunderstorm area tonight, with the marginal/slight risk
area far to our south along the Gulf Coast. Hourly grids are
holding up well, and see no reason to make any changes to the
forecast at this time.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR flight rules for the first couple hours of this TAF cycle,
but with our next weather maker approaching, conditions will
deteriorate. Light to moderate rains will start after 03Z for
KBNA/KCKV and while it will take a little while, vis and cig will
start to drop. It could be daybreak before KCSV falls. MVFR
should be the worst of it at all 3 mid-state terminals, at least
for this TAF cycle. I did remove the TS wording for now, as it`s
very isolated.
Winds will slowly begin to increase tonight, with southerly gusts
beginning around daybreak.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 61 68 47 55 45 / 80 100 70 70 40
Clarksville 59 65 47 55 43 / 90 90 70 60 30
Crossville 58 66 45 52 42 / 50 90 60 80 60
Columbia 59 65 46 54 43 / 80 100 60 70 30
Lawrenceburg 60 66 46 55 44 / 80 100 60 70 40
Waverly 59 64 46 55 44 / 90 80 70 60 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......08
AVIATION........Unger
Area Forecast Discussion
National Weather Service Springfield MO
621 PM CDT Wed May 3 2017
.SHORT TERM...(This evening through Thursday)
It was a chilly and damp day across extreme southeast Kansas and
the Missouri Ozarks. The additional rainfall last night and this
morning caused widespread flooding of low water crossings and low
lying areas. MODOT travelers map shows numerous state routes that
are impassable to motorists.
Additional rainfall is expected tonight as the upper level cold
core approaches southwest Missouri from the west. The HRRR is
suggesting another one to two inches area wide.
Look for overnight lows to fall into the low 40s.
For Thursday, rain will shift out of the region early in the
morning. Another cool day is in store with most locations only
warming into the 50s.
.LONG TERM...(Thursday Night through Wednesday)
A much needed extended period of dry weather is expected beyond
early Thursday morning. The upper flow regime becomes blocked as
ridging slowly builds into the nations mid section from the west.
Look for above average temperatures and plenty of sunshine Friday
through early next week.
Medium range models are signaling our next storm system to
approach by the middle of next week. Models are showing a closed
low. Typically these systems are very difficult to diagnose as
models tend to not handle the timing or structure very well.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 620 PM CDT Wed May 3 2017
For the KSGF, KJLN, and KBBG TAFS: Drizzle and rain will continue
to impact the TAF sites this evening into the overnight hours.
The rain and drizzle should begin to end from west to east
by early Thursday morning. IFR ceilings will occur this evening
and tonight with VFR conditions returning Thursday morning and
afternoon. Reduction in visibility will also occur this evening
and tonight especially in the heavier areas of rain/drizzle.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Flash Flood Watch through Thursday morning for MOZ055>058-
066>071-077>083-088>098-101>106.
KS...Flash Flood Watch through Thursday morning for KSZ073-097-101.
&&
$$
SHORT TERM...Cramer
LONG TERM...Cramer
AVIATION...Wise