Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/23/17

Area Forecast Discussion
National Weather Service Albany NY
1033 PM EDT Tue Aug 22 2017 .SYNOPSIS... Showers and thunderstorms will be ending overnight from west to east as a cold front passes through the region. Behind this front, cooler and less humid air will move into the region for Wednesday with a partly to mostly sunny sky. Mainly dry and comfortable weather is expected for the rest of the week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 1033 PM EDT...Surface cold front is now located over western New York and it continues to track eastward towards our area. Ahead of the boundary, MRMS imagery continues to show two bands of convection, with the heaviest activity now stretching from western New England back towards the Hudson Valley. The threat for the strongest and damaging winds along this line are now mainly located east of area from southwestern NH towards the CT River Valley of western Massachusetts, although pockets of gusty winds and locally heavy rainfall are still ongoing across our parts of extreme eastern NY and western New England. The Severe Thunderstorm Watch is still in effect until Midnight, although it may be able to be cancelled early if radar trends continue. MRMS is showing 1 hour rainfall totals in excess of one inch across parts of central Berkshire County, so the threat for localized urban/small stream flooding is still in place for the next few hours. Some heavier rainfall of 0.50 to 0.75 inches per hour is also occurring across parts of the eastern Catskills and mid Hudson Valley as well. Heavy rainfall should be progressive enough to avoid widespread flash flooding, but will need to watch MRMS trends closely over the next few hours. 3km HRRR shows the main band of convection should continue to slide eastward and the secondary band of lighter activity just ahead of the front should weaken and dissipate by 1 or 2 AM. The front should cross the area by late tonight, but any notable cooling or drier air moving into the area probably won`t occur until during the day Wednesday. Skies should start to clear out by late tonight with the passage of the front. With the frontal passage not occurring until very late, it will still feel rather sticky and mild overnight, with lows in the 60s for most locations. Some patches of fog will likely develop late in the overnight, especially in areas that saw heavier rainfall. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Behind the front, cooler and less humid air will work into the region. Mainly dry weather is expected through Wednesday, although cannot totally rule out a lingering rain shower across the Adirondacks or Mohawk Valley for later Wednesday into Wednesday night, as the passing upper level trough picks up some moisture off Lake Ontario and allows for a lake-enhanced shower or two. Highs on Wednesday will reach the mid 70s to low 80s. Overnight lows will mainly be in the 50s, with some 40s across the higher elevations. Sky cover will generally be partly cloudy. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Extended period of fair weather with slightly below normal temperatures. Canadian high pressure at the surface will build in and shift southward as it expands across the Great Lakes region and the Northeast over the weekend into early next week. An upper level trough will remain over region. Short waves are expected to rotate through the trough on Thursday and Friday. Some afternoon showers possible each day from sun`s heating and cold air/troughiness aloft, mainly over higher terrain. Looking at temperatures around 5 degrees below normal with highs generally in the mid 60s to upper 70s and lows in mid 40s to mid 50s. Cooler readings are expected across the higher terrain of the western Adirondacks, eastern Catskills and southern Green Mountains of Vermont. In addition to the cooler temperatures, we will have low humidity levels with dew points in the 40s and lower/mid 50s. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Line of showers and some strong thunderstorms currently extends from the Lake George area to KGFL southwest to the Catskills. We expect this line to continue to move southeast this evening and bring thunderstorms to all the TAF sites between 23/00Z and 23/05Z. Some fog may develop after midnight with the moist ground and rain cooled atmosphere. At this time, expecting only MVFR fog as winds and drying behind the cold front should be strong enough to keep dense fog from forming. Frontal passage is expected between 06Z and 12Z Wednesday with the winds shifting from southwest to the northwest behind the front. Winds Wednesday will be mainly from the northwest at 5 to 15 kts. Outlook... Wednesday-Saturday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... Most areas should see a wetting rainfall this afternoon and evening due to the passage of a pre-frontal trough and surface cold frontal boundary. Southerly winds will be 15 to 20 mph today with gusts up to 30 mph, and will switch to the west by tonight at 5 to 15 mph. Behind the front, cooler and less humid conditions will be in place for the rest of the week. RH values look to fall to 45 to 55 percent on Wednesday afternoon with westerly winds of 10 to 20 mph. && .HYDROLOGY... A line of strong to severe thunderstorms will cross through the area this afternoon and evening. Any thunderstorm will be capable of producing locally heavy downpours and could lead to isolated flash flooding. The locally heavy rainfall may also result in minor flooding of urban, poor drainage and low lying areas. Behind this frontal system, mainly dry weather is expected for the rest of the week. Basin average rainfall on Tuesday will generally be around a half of an inch to an inch, although point totals may be higher. This rainfall will only allow for minor rises on rivers and streams. River and stream levels should quickly recede by Wednesday and then remain steady for the rest of the week. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .EQUIPMENT... The KENX radar will likely be down through at least Friday, September 1st for the bull gear replacement. We are waiting for a ROC maintenance team and parts to arrive to assist local technicians with the repairs. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Severe Thunderstorm Watch until midnight EDT tonight for CTZ001-013. NY...Severe Thunderstorm Watch until midnight EDT tonight for NYZ047-051>054-058>061-063>066. MA...Severe Thunderstorm Watch until midnight EDT tonight for MAZ001-025. VT...Severe Thunderstorm Watch until midnight EDT tonight for VTZ013>015. && $$ SYNOPSIS...Frugis NEAR TERM...Frugis SHORT TERM...Frugis/JVM LONG TERM...SND AVIATION...SND FIRE WEATHER...JVM HYDROLOGY...JVM EQUIPMENT...WFO ALY
Area Forecast Discussion
National Weather Service State College PA
1035 PM EDT Tue Aug 22 2017 .SYNOPSIS... A strong cold front will move through the region overnight. Much cooler and drier conditions will return for the second half of the week into the weekend. Temperatures will average a few degrees below normal highs starting tomorrow and lasting into early next week. && .NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/... The last of the potentially severe storms has cleared Lancaster county. Additional showers are moving east along ther Maryland border and there is also a line of showers moving through the northern mountains. The main windshift line associated with the cold front is just now entering NW PA. The RAP anal shows the frontal trough jumping out to the east over central PA. The front will continue to accelerate through the area overnight ushering in markedly drier air by morning. POPs will taper off rapidly after midnight as drier air moves in behind the front. Some areas of fog are possible late at night as skies beging to scatter out. && .SHORT TERM /8 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... Wednesday will be noticeably drier as the PW values crash to -1 sigma below normal after being well +1 to +2 sigma above normal. It will also be significantly cooler. The 850 hPa temperatures fall to near normal Wednesday and will fall below normal overnight Wednesday into Thursday. Chance of rain should be very low Wednesday. The cool air aloft will likely produce some cumulus in the mountains during the afternoon hours. It should be a nice and notably cooler day. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... An extended period of early autumn-like weather will begin Wednesday and continue right through the upcoming weekend as a -2 sigma upper trough (and similarly anomalous/cool 850 mb temps) move over the Great Lakes and NE U.S. 1026-1028 mb SFC High (+2-3 Sigma) over south-central Canada will drift slowly to the Great Lakes by this weekend Daytime high temps will be about 5-7 Deg F below normal across the Western Mtns on Wednesday, though still just slightly below normal across the SE zones prior to the arrival of the deeper/colder air for the latter part of the week. GEFS mean 850 mb temps will dip about 2-3 deg C in all locations for Thursday-Sunday, leading to max temps averaging 5-10 F below normal (with min temp departures about 10-13F below normal Friday-Sunday) as a large Canadian High Pressure area pushes SE across the Glakes Region and becomes centered over the NE states. Lows Fri/Sat/Sun mornings with high centered overhead will be dipping into the l-m 40s over the Northern Mountains (and deeper valleys of the Central Mountains) and solidly into the 50s elsewhere. Some of the perennial cold spots near and to the east of KBFD could see readings of 38 or 39F. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Most of the eastern areas mostly sunny with some cumulus clouds about making for a bumpy ride in the boundary layer. Over western PA and OH there is a line of strong and severe storms. Strong winds and large hail are possible. Check radar before flying over western PA this afternoon and central areas this evening. The line of storms will move east this afternoon and evening. Areas of patchy fog will develop around/after midnight. Spotty MVFR and IFR. Conditions will improve rapidly Wednesday morning, as cool Canadian high pressure builds into the area. .OUTLOOK... Wed...AM low cigs BFD/JST, otherwise VFR. Thu-Sat...No sig wx expected. && .EQUIPMENT... KCCX is fixed with new motor installed. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...La Corte SHORT TERM...Grumm LONG TERM...La Corte/Lambert AVIATION...Grumm/Lambert EQUIPMENT...
Area Forecast Discussion
National Weather Service Green Bay WI
1052 PM CDT Tue Aug 22 2017 Updated aviation portion for 06Z TAF issuance .SYNOPSIS... Issued at 220 PM CDT Tue Aug 22 2017 Generally quiet late-summer weather into early next week. Seasonably cool the next couple days, then temperatures close to normal. The large scale pattern will complete an amplification cycle the next couple days as a rather strong upper trough becomes established from eastern Canada into the lower Great Lakes region. Jet energy working east across Canada will cause the trough to begin weakening by late in the week. By early next week, the main westerlies will recede north into Canada, leaving just a weak remnant of the trough lingering across the forecast area. Temperatures will begin the period below normal, then rebound to near normal levels by the weekend. Rainfall will be limited with precipitation events consisting of just scattered showers. As such, amounts for the period are likely to end up below normal. && .SHORT TERM...Tonight and Wednesday Issued at 220 PM CDT Tue Aug 22 2017 The latest RAP analysis and satellite/radar imagery show upper troughing settling over the western Great Lakes early this afternoon. A widespread cu field has developed across the region, though cu has the most vertical extent over far northwest WI and northeast MN where the highest capes reside. Some of this more enhanced cu and even a few showers will move into north-central WI later this afternoon. As cold air continues to funnel across the region, forecast concerns revolve around light showers early this evening, followed by lake effect showers/drizzle late tonight. Tonight...As a secondary surge of cold air arrives from the northwest tonight, high res models continue to indicate that scattered showers will persist over north-central WI through the mid evening hours. Then attention turns to precip off western Lake Superior overnight. 1000-850mb flow veers around to the NNW direction after midnight, which is a good trajectory for showers or drizzle to move into north-central WI. Increased cloud cover some late as a result, but 10-15 kts of low level flow should not be strong enough for these clouds to move into central or east-central WI. With enough wind to prevent temps from tanking, should see lows ranging from the mid 40s north to mid 50s south. Wednesday...Broken cloud cover along with patchy drizzle/showers will likely linger into the mid-morning hours over northern WI. With day time heating, however, think mixing will cause these clouds to scatter by midday. Elsewhere, should see scattered fair weather cu develop, which will lead to a partly cloudy day for most. Highs ranging from the low 60s in the far north to mid 70s at Wautoma. .LONG TERM...Wednesday Night Through Tuesday Issued at 220 PM CDT Tue Aug 22 2017 At low-levels, a cool, dry Canadian air mass will settle across the area and linger through the weekend. Some pretty chilly nights are likely unless clouds move through during the nighttime hours. The typical cool spots across the north will probably fall into the 30s Wednesday night and Thursday night, and would not be surprised if there is some patchy frost. The anticyclone and its associated air mass will linger across the area for much of the forecast period, but moderation of the air mass should allow temperatures to rebound to near seasonal levels by the weekend. While the dry anticyclone dominates at low-levels, the forecast area will be at least brushed by some middle and upper level shortwave energy at times. That will lead to some clouds and maybe some showers. But given the limited moisture, any rains are likely to be scattered and light. Tweaked mins down in the typical cool spots Wednesday night and Thursday night, but tempered the adjustments some due to uncertainty about passing clouds. Otherwise, the standard forecast initialization grids based on a broad blend of model output seemed reasonable, so no other significant changes were necessary. && .AVIATION...for 06Z TAF Issuance Issued at 1026 PM CDT Tue Aug 22 2017 VFR conditions will rule over most of the TAF sites through the period. The one main exception will be across far north-central Wisconsin where cool north-northwest flow off Lake Superior will bring some low clouds and patchy light showers or drizzle overnight. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kurimski
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
251 PM PDT Tue Aug 22 2017 .SYNOPSIS...Near normal temperatures will persist across central California through Friday with a warming trend this weekend into early next week. Otherwise...thunderstorms will be possible over the Sierra Nevada each afternoon and evening through Thursday. && .DISCUSSION...An upper low remains nearly stagnant off the central California coast this afternoon...bringing another shot of showers and thunderstorms to the Sierra Nevada this afternoon and early evening. Showers were developing across the Sierra from Fresno county north toward Yosemite National Park. Any storms that do form are forecast to move north northeast. The HRRR and high res ARW are showing very little activity this afternoon and evening while the NMM and NAM are showing quite a bit more activity. Either looks like the Sierra should see quite a bit less activity compared to the past few days. In addition to thunderstorms...the upper low has kept temperatures seasonable across the area....with San Joaquin Valley readings forecast to top out in the mid 90s. The upper low is forecast to move slowly east southeast into southern California early Wednesday afternoon...resulting in an increase in thunderstorm activity. The high res models are in good agreement tomorrow...especially from Sequoia National Park northward. The movement of storms tomorrow will switch to a more westerly direction...with possible thunderstorm cloud blow off possibly entering the foothills and valley by the early evening hours. There is a possibility of thunderstorms again on Thursday...however confidence is much lower compared to today and especially Wednesday. Upper level high pressure will begin to build over the desert southwest Friday into the weekend resulting in a warming trend across the region. Triple digits will once again be possible over the San Joaquin Valley Saturday and continue into the weekend. Dry weather will also prevail across the area Friday into at least early next week with high pressure firmly in place. Unfortunately the above normal temperatures do not look to come to an end anytime soon. According to the Climate Prediction Centers 8 to 14 day outlook (valid from August 30th through September 5th) there is a good chance of above normal temperatures for the entire west coast. && .AVIATION... Isolated to scattered thunderstorms will occur over the Sierra after 20z today through 03z Wednesday. Areas of smoke are possible Near Yosemite National Park in association with the South Fork Wildfire. Otherwise VFR conditions can be expected over much of the central CA interior during the next 24 hours. && .AIR QUALITY ISSUES... Please see SFOAQAHNX for an Air Quality Alert None. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is high. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... NONE. && $$ public...Riley avn/fw...Riley synopsis...Riley
Area Forecast Discussion
National Weather Service Wilmington NC
740 PM EDT Tue Aug 22 2017 .SYNOPSIS... Warm and humid weather will prevail through mid week. An approaching cold front will bring increasing storms over the area late Wednesday into Thursday. Canadian high pressure will bring an early fall feel Friday and into the weekend. Breezy conditions may develop late Sunday into Monday, as a possible tropical low passes offshore and interacts with the Canadian high. && .NEAR TERM /THROUGH WEDNESDAY/... As of 730 PM Tuesday...Weak high surface high pressure off the coast will begin to retreat tonight as the pressure trough surrounding a cold front over the Ohio Valley approaches from the northwest. Pressures should fall by about 3 millibars along the coast tonight in advance of this feature. Diurnal thunderstorms are diminishing now that the sun is setting and the boundary layer is stabilizing. Short-range high res models (HRRR and NAM) show no precip potential for the next 8-9 hours. What may develop some showers or t-storms late tonight or Wednesday morning is the landbreeze. In the same way the seabreeze develops due to air temperature/density differences, cooler air inland will surge offshore late tonight creating a boundary that can initiate convection and precip. The HRRR is focused on the 6-8 AM timeframe along the beaches and just offshore. With the steering flow aloft I imagine the bulk of any activity will develop and remain offshore. No significant changes have been made to overnight low temperature forecasts, still mid to upper 70s for most locations. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 300 PM Tuesday...Cold front entering western zones in addition to some height falls and weak vorticity centers ahead of the main belt of westerlies buckling into deep troughiness north of New England States. With several factors leading to lift thunderstorms will not exhibit their normal diurnal decrease, or at least display a much lessened one. Wind fields look weak enough to preclude a severe weather threat. Shower and thunderstorm chances will remain pretty high early Thursday night, highest along the coast. Then some dry air pushes in rather strongly from NW to SE during the latter portion of the overnight hours. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 300 PM Tuesday...The mid level pattern will initially feature a decent trough for late August. The flow will quickly transition to a more zonal configuration by the end of the weekend. At the surface a cold will push into the Bahamas by early Saturday with high pressure building down into the Carolinas. Friday and Saturday should be cooler and mostly dry although the easterly flow may keeps some low clouds and perhaps a light shower or two offshore around. The forecast gets interesting later in the period when the global guidance spins up what could be a tropical system along the residual front and moves it up off the southeast coast. The guidance has been showing this for a few cycles but the disclaimer of its pretty far out in time still holds. I did keep a partly to mostly cloudy forecast intact with some pops increasing especially along the coast. Temperatures will be on the cool side especially for highs more near normal for overnight lows. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... As of 00Z...A cold front approaching the area from the northwest is still west of the Appalachians and won`t directly affect our area until Wednesday night at the earliest. Today`s afternoon thunderstorms are falling apart now that the sun is setting and we`re expecting the next 8-9 hours to be quiet with only mid- level altocumulus and perhaps a little low cumulus near the coast. A landbreeze should develop an hour or two before sunrise. This boundary will develop scattered showers and maybe an offshore thunderstorm. These will probably just far enough east to not have significant effects on the coastal airports (ILM, CRE, MYR) however they may approach within the vicinity (5-10 miles). Where surface wind speeds are lightest inland, MVFR visibilities are possible at FLO and LBT. Scattered showers and t-storms should pop up during the heat of the day Wednesday. The best potential should be near the coast during the late morning and early afternoon, shifting farther inland during the mid to late afternoon with the seabreeze. Extended Outlook...Showers and t-storms Wednesday night and Thursday associated with a cold front could produce localized IFR conditions. Most showers and storms will push offshore Thursday night into Friday. MVFR ceilings could linger, especially near the coast Friday. && .MARINE... NEAR TERM /THROUGH WEDNESDAY/... As of 730 PM Tuesday...Falling pressures across interior North Carolina and Virginia tonight ahead of an approaching cold front should keep wind speeds up in the 10-15 kt range most of the night. Seas already 2.5 to 3.5 feet could build by another 0.5 to 1 foot by late tonight in a choppy short-period wind wave. Shower activity is currently absent from the coastal waters, however a landbreeze pushing off the coast between 4-6 AM should help develop a line of showers and perhaps a thunderstorm around sunrise. SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 300 PM Tuesday...Prefrontal flow regime Wednesday night will have a few knots of wind speed knocked off as cold front and its associated pressure trough approaches. The front will move quite slowly and so most of Thursday will feature very gradually veering winds, through FROPA itself will still likely lead to a quicker turn to NE. With the front nearly stalling not far to our south the NE winds will not pick up significantly. LONG TERM /FRIDAY THROUGH SUNDAY/... As of 300 PM Tuesday...Not the best of weekend`s coming up for the marine community as high pressure will be building down into the area from the north. At the same time a front will become stationary to the south and keep the gradient elevated. For basically the entire period expect northeast winds of 15-20 knots. Seas will be elevated as well with values from 3-6 feet. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...SHK NEAR TERM...TRA SHORT TERM...MBB LONG TERM...SHK AVIATION...TRA
Area Forecast Discussion...CORRECTED
National Weather Service Medford OR
326 PM PDT Tue Aug 22 2017 .Edited portion of AFD. .DISCUSSION...Over the next 7 days the weather conditions will evolve from warm and unstable to cool and stable, to hot and dry...with continual periods of smoke affecting the forecast area. The next two days will feature thunderstorm chances, focused today over northern California, extending into Southern Oregon later this afternoon and evening. There is potential for nocturnal storms as disturbances aloft make their way south to north into Oregon. Tomorrow a cold front will approach the forecast area and gradually introduce a westerly component to the upper level winds, drying out the midlevels and stabilizing the atmosphere. This will push the threat from thunderstorms eastward tomorrow, primarily along and east of the Cascades. We have Red Flag Warnings out at RFWMFR for the expected abundant lightning on dry fuels today and tomorrow. Some of the storms will produce heavy rain, and we have a Flash Flood Watch at FFAMFR to highlight the threat for flash flooding on some of the recent wildfire burn scars in Siskiyou and Modoc Counties. Note that we do expect plenty of lightning outside of storm cores, so new fire starts are still expected despite some wetting rainfall. Smoke is another big concern, impacting a majority of the forecast area. In general, air quality has trended similar or worsened compared to yesterday. The HRRR smoke models suggest some improvement tomorrow but with similar wind flow, we have maintained an Air Quality Alert out through tomorrow afternoon for much of the West Side, Cascades, and portions of the East Side to around Highway 97. Brookings and the Curry County coast should continue to see periods of poor air quality through tomorrow at least, based on weak winds, overnight drainage northeast winds down the Chetco drainage, and the abundant smoke from the nearby large fire. A cooler air mass, not surprisingly, will accompany the cold front on Thursday, but this trend towards lower temperatures will be very brief. 850mb temperatures, a good indicator for trends of surface temperatures, rise starting Friday and peak Monday or Tuesday. 850mb temperatures reach the top 5 percent for this time of year on Monday per GEFS output, and temperatures could reach 100 degrees in the Rogue Valley. The surface temperatures will partially depend on the amount of smoke in the area, so that will have to be continually evaluated. Needless to say, the fire environment will become hotter and drier late this week into the weekend. We have increased northeasterly overnight winds near the coast as the thermal trough strengthens into the weekend. Looking at cross- sections of the atmosphere on Monday, relative humidity values throughout the column are all 10 to 25 percent...indicating an extremely dry air mass. && .AVIATION...22/18Z TAF CYCLE...Onshore flow is keeping LIFR/IFR cigs/vis at the coast and just offshore. It is possible that the OTH TAF site sees some clearing this late morning and early afternoon with some breaks in the cloud decks. Elsewhere smoke from wildfires blanket southern Oregon and this is affecting visibility at most terminals. Look for visibility to drop down to to IFR at some sites and MVFR for inland areas because of the smoke. Isolated to scattered thunderstorms are possible later this afternoon and evening with Klamath Falls at greater risk for thunderstorms near or over the terminal. -Petrucelli/Smith && .MARINE...Updated 130 PM PDT Tuesday 22 August 2017...A weak thermal trough near the coast will strengthen Thursday...bringing increasing north winds and steep seas to the area into the weekend. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning until 11 PM PDT this evening for ORZ621-623>625. Red Flag Warning from 1 PM to 8 PM PDT Wednesday for ORZ624-625. Flash Flood Watch until 11 PM PDT this evening for ORZ028. CA...Red Flag Warning until 11 PM PDT this evening for CAZ280>282-284-285. Red Flag Warning from 1 PM to 8 PM PDT Wednesday for CAZ285. Flash Flood Watch until 11 PM PDT this evening for CAZ080-084-085. Pacific Coastal Waters...Small Craft Advisory from 11 PM this evening to 5 AM PDT Thursday for PZZ356-376. $$ NSK/NSK/CZS
Area Forecast Discussion
National Weather Service Morristown TN
924 PM EDT Tue Aug 22 2017 .DISCUSSION...Initial broken line of showers and thunderstorms has basically faded away in the relatively stable air well ahead of the main pre-frontal trough making progress through Middle Tennessee. RAP, HRRR predict quite a bit of weakening of the southern portion of the line heading through the post midnight period, although the WRF doesn`t agree. Believe there will be continued weakening as convection gets closer to the forecast area but not as much as the previously mentioned mesoscale models. Therefore, will tweak pops up a little south of I-40. Temperature drop will be held up a bit under the alto cu ceilings advancing with the front but current forecast looks ok. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...None. TN...None. VA...None. && $$
Area Forecast Discussion
National Weather Service Pueblo CO
320 PM MDT Tue Aug 22 2017 .SHORT TERM...(This evening through Wednesday) Issued at 319 PM MDT Tue Aug 22 2017 Thunderstorms developing over the mountains and along the Raton Mesa at mid-afternoon, with very slow n-ne drift to most convection. Air mass over the plains is moderately unstable, but soundings suggest a rather stout cap will continue to suppress convection, especially east of I-25. HRRR occasionally suggests a few storms may drift eastward across the I-25 corridor and along the NM border later this the evening, so will keep some low pops in place along and west of the interstate. Models suggest best coverage of convection will be across the central mountains late this afternoon, with perhaps some southward development into the nrn San Luis Valley during the evening. Given slow storm motions and weak shear, main storm threats will continue to be flash flooding, especially over recent burn scars. Convection fades away overnight, with just some sprinkles lingering over the peaks by early Wed morning. On Wed, a little less in the way of convection over the mountains as air mass dries slightly, though still enough moisture for isolated to low end scattered pops most areas. Cap looks weaker on the plains, with both NAM and GFS developing some isolated storms along and east of I-25 from very late afternoon into the evening. Again, flash flooding will be the main storm threat, though swly steering currents do increase as weak upper jet migrates eastward across CO, which should lead to slightly faster storm motions versus the past few days. Max temps will climb back toward seasonal values, with 3-6 degf of warming at many locations. .LONG TERM...(Wednesday night through Tuesday) Issued at 319 PM MDT Tue Aug 22 2017 Wed night an upper level ridge will be over the area with enough moisture over the area for isold to sct showers/tstms. The GFS has better chances for pcpn Wed night than the NAM. On Thu an upper level disturbance moves acrs CO, aiding in the development of pcpn acrs southern CO. The forecast models are still showing better pcpn chances for the southeast plains Thu night as that disturbance moves acrs the area, with the potential for areas of heavy rain. There could also be a few severe storms over the eastern plains. The upper ridge rebuilds over the area on Fri behind that upper wave, and Fri looks drier, although there should still be isold to sct pcpn mainly over the higher trrn. On Sat the upper ridge will be centered over the Great Basin, with north to northwest flow aloft over southern CO. A weather disturbance is forecast to move through eastern CO in that northwest flow in the afternoon and evening, and it looks like fairly widespread pcpn could occur over the southeast plains. The upper ridge remain centered over the western states on Sun. The best chances for pcpn on Sun are expected to be over the mtns, but a disturbance may brush the far eastern portions of CO Sun night, bringing increased pcpn chances to areas near the KS border. The northerly flow aloft continues on Mon, with yet another disturbance making its way south acrs the area to help increase pcpn chances through Tue morning. A sfc fronts moves into southeast CO Tue. After the morning hours, the plains may dry out but the mtns and adjacent areas should see pcpn in the afternoon and evening. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 319 PM MDT Tue Aug 22 2017 TSRA will continue over the mountains this afternoon and evening, and will include a VCTS mention at KALS as a few storms may drift across the San Luis Valley. Also a low chance of a TSRA at KCOS this evening as storms move away from the mountains, though for now will monitor radar trends and keep any mention out of the TAF until storm coverage increases. Convection slowly decreases overnight with VFR conditions most areas by Wed morning. Cycle continues Wed afternoon with storms developing over the mountains after 18z, then drifting toward lower elevations beginning 20z. Terminals will have a low chance of storms after 20z, though storm coverage will remain fairly isolated at lower elevations. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...PETERSEN LONG TERM...28 AVIATION...PETERSEN