Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/04/23

National Weather Service Wakefield VA
904 PM EST Tue Jan 3 2023 .SYNOPSIS... High pressure continues to move offshore this evening. Rain chances hold off until after midnight with the bulk of the rain falling tomorrow afternoon, as a cold front approaches and pushes into the region. Temperatures will fall back to around average by the weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 900 PM EST Tuesday... Evening analysis shows low pressure over IL with a warm front extending to the east across northern IN, OH, and PA. Mid and high level clouds have moved in from the SW with radar showing a few echoes aloft over the SW corner of the CWA. This precip is likely not reaching the surface with low reflectivity and dew point depressions still running 5-10 degrees. Cut PoPs back for much of the overnight with chance PoPs confined the south and southwest prior to sunrise. Temperatures have been roughly steady through the evening and are not expected to fall much given continued warm advection, winds 5-10 kt, and increasing cloud cover. Lows in the upper 50s to low 60s will obviously be well above seasonal norms and record high minimum temps are likely in jeopardy at a few sites. See climate section below. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... As of 250 PM EST Tuesday... The low pressure system (currently over the Plains) becomes vertically stacked as it slowly tracks into the Great Lakes from Wed- Thu. The associated cold front will cross the region Wed night-Thu AM. Very mild/breezy with a noticeable increase in humidity on Wed. S-SW winds are expected to gust to ~25 mph and dew points will rise into the low-mid 60s by late in the day. Forecast highs range from the upper 60s W to the mid 70s SE. Hi-res models disagree on just how much rain the FA will see from this front. HRRR is the most aggressive so far, bringing a decently strong (for January) line of showers/tstorms through the area, while other models mostly break up the line once it gets here. Decided to limit highest PoPs to the northwestern third counties during the early afternoon hours (~70%). Lowered the PoPs to 50-60% as the progresses E later in the afternoon/evening. The front and associated precip should be offshore by early Thursday morning. Regarding thunder, still sticking with a slight chance in the afternoon. SPC is maintaining a MRGL Risk for severe wx across SE VA/NE NC on Wed (mainly during the aftn/evening), but there is still a lot of spread in the guidance, and am not confident that we will see enough instability to break the capping inversion evident on model soundings between 850-700 mb. CAA will be very weak w/ the initial FROPA. Lows Wed night generally in the 50s. Highs Thu in the 60s (but with noticeably less humidity). A secondary (stronger) push of CAA arrives Thu night as the low pressure system tracks into srn Ontario/Quebec. Still above average Thu night with lows in the upper 30s-mid 40s. The low pressure system (at the sfc and aloft) will finally cross the Atlantic Coast and move offshore Friday into Saturday. Areas along the MD Eastern Shore could see some light rain associated with this Friday. Much cooler on Fri with highs in the low-mid 50s. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 250 PM EST Tuesday... Expecting mostly dry weather through the weekend. The deterministic global models show a weak system tracking across the area (bringing light rain to NW portions of the FA) late Sat-Sun AM. Added a slight chance of showers for these areas, but given the dry air at the surface, would not be surprised if not much made it to the ground. Seasonable temperatures return this weekend as high pressure builds to the north. Highs will mainly be in the mid 40s-lower 50s from Sat- Mon. Lows Sat AM in the upper 20s-mid 30s, then 30s Sunday morning, and upper 20s-mid 30s Mon AM. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... As of 630 PM EST Tuesday... VFR conditions in place this evening with some scattered to broken mid and high level clouds streaming into the region from the W and SW. Winds at the terminals are generally SSW 10-15 kt as the gradient remains tight between high pressure offshore and an approaching cold front. Some LLWS noted on forecast soundings that will likely persist well into tonight. CIGs gradually lower from W to E by early Wednesday morning with IFR conditions most likely at RIC and SBY and MVFR to the SE. SW winds increase after sunrise with gusts 15-20 kt. Showers move in from the west by early afternoon with the chance for some thunder, especially at the SE terminals, though not confident enough in timing/coverage to mention specifics yet. Outlook: the cold front will push offshore by early Thursday morning. Other than a slight chance of showers at SBY on Friday, expecting dry and VFR conditions through the weekend. && .MARINE... As of 250 PM EST Tuesday... This afternoon, high pressure is located well offshore and a slow moving cold front is located west of the region. SSW winds have increased this afternoon due to the tightening pressure gradient between the two systems. SSW winds are generally 10 to 15 knots with gusts to ~20 knots. Seas range from 2 to 4 feet, and waves in the Chesapeake Bay are running around 2 feet. Winds will increase to around 15 to 20 knots with gusts up to 25 knots across the bay and 20 to 25 knots with gusts up to 30 knots across Atlantic coastal waters later this evening into tonight. Winds will likely peak this evening. Small Craft Advisories remain in effect for the Chesapeake Bay, Lower James, and coastal waters north of Cape Charles through tonight. The SSW winds will continue through Wednesday, but there may be a period of lighter winds early Wednesday morning before increasing again during late morning and afternoon. Therefore, have still held off on any additional SCAs, but SCAs will likely be needed again for at least the coastal waters Wednesday evening and overnight. The cold front is forecast to move off the coast early Thursday morning. Winds will weaken behind the front and turn from the NW on Thursday, as there will not be much cold air advection immediately following this front. NW winds will increase later in the week as colder air moves into the region. Waves in the bay are expected to increase to around 3 ft later today through Wednesday as southerly winds increase. Seas north of Cape Charles will increase to 3-6 ft, and 2-5 ft south later today though Wednesday.&& .CLIMATE... As of 630 AM EST Tuesday... Very mild-warm wx is expected through Wednesday, possibly challenging a few daily records at long-term climate sites which are listed below. Record Highs: * Site: Tue 1/3 Wed 1/4 * ORF: 76 (2004) 78 (2004) * RIC: 74 (2000) 76 (2005) * SBY: 70 (2000) 72 (2000) * ECG: 73 (2000) 76 (2000) Record High Mins: * Site: Wed 1/4 * ORF: 62 (2004) * RIC: 57 (2004) * SBY: 60 (1950) * ECG: 60 (2015) && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 4 AM EST Wednesday for ANZ630>632- 634-638. Small Craft Advisory until 8 AM EST Wednesday for ANZ650-652- 654. && $$ SYNOPSIS...RHR NEAR TERM...RHR SHORT TERM...AM/ERI LONG TERM...AM/ERI AVIATION...RHR MARINE...AJB CLIMATE...
National Weather Service Albany NY
959 PM EST Tue Jan 3 2023 .SYNOPSIS... warm front will continue to bring scattered showers and patchy drizzle overnight. Temperatures will remain steady or slightly rise with plenty of clouds, as the front stalls over New York and central New England. As the front returns back southward on Wednesday, temperatures will be falling through the day after a mild start, with more rain for late Wednesday into Wednesday night. The rain may change to a wintry mix across northern and eastern parts of the area for Wednesday night into Thursday. Some lingering rain or snow showers may continue into Friday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... .UPDATE as of 958 pm EST...The warm front is just north of the NY-PA border and extends eastward into southern NY and southern New England. The rain shield has dissipated and transitioned into scattered to numerous showers with some patchy drizzle. The water vapor loop shows the short-wave has moved east of the region near southeast New England. The 00Z 3-km HRRR continues to show a weak sfc wave move along the boundary over the next few hours until midnight to 2 am, so we maintained some likely PoPs before going to scattered the rest of the night for the majority of the area. Temps continue to be stagnant and slow rising, except over the higher terrain to the south and east of the Capital Region with the warmest readings over the southern Taconics and southeast Catskills in the NYS mesonet. Overall, temps continue to be cool with the dank conditions with 30s to lower 40s in the valley areas and from the Mohawk Valley/Capital Region northward based on the NY mesonet and 30s and lower 40s across the Berkshires and southern VT. Tannersville has reached 53F and Copake 49F this hours. Locations to the north of I-90 will continue to rise slowly into the mid to upper 30s. Locations along and to the south closer to the boundary or on the south side will be in the upper 30s to lower 50s. The boundary likely will stall near the I-90 corridor. Patchy fog was expanded across the area through day break in the damp air mass. Rainfall amounts have been in the tenth to half inch range in the NYS mesonet and METAR observations with the higher amounts south and west of the Capital District. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... At the start of Wednesday, our area will be under broad southwest flow aloft, with a digging trough to the west and ridging just off the eastern seaboard. There should be a break in the precip for Wednesday morning into the start of Wednesday afternoon, although there still will be plenty of clouds around. Temps will vary considerably across the area, depending on just where the boundary remains stalled. Model guidance has been having issues with the exact placement and this has been showing large variations in the potential for temps on Wednesday. Northern areas will probably remain rather chilly in the 30s, while far southern areas should be mild, with highs well into the 50s. The middle area (including the Capital Region) is the highest uncertainty. For now, it looks like the day may start somewhat mild in the 40s, but temps will likely be falling in the afternoon, as the boundary starts shifting back southward. Another round of steady precip looks to occur for Wednesday evening into Wednesday night, as the next wave of low pressure moving along the stalled boundary heads towards the area from the southwest. All areas should be starting out seeing some steady plain rainfall on Wed evening. However, northern areas will be starting to shift to freezing rain and possibly some sleet through the overnight, as the low-level cold air bleeds southward into the area from the North Country. This will be most likely in the upper Hudson Valley (from Indian Lake and North Creek southward towards Hadley) and in the Lake George/Glens Falls area, as cold air drains down the Champlain Valley. Also, parts of southern VT (especially just along and east of the Greens) will start to see a threat for some mixed precip towards late Wednesday night as well. The steadiest precip should end towards daybreak Thursday, but any lingering precip may be wintry for early Thursday for the rest of the Adirondacks, southern VT and into the northern Berkshires as well. A light accretion of flat ice (mainly a trace to 0.25 of an inch) is expected for these northern and eastern areas, with the highest totals in northern Warren and northeastern Hamilton Counties NY. Elsewhere, the precip will stay just rain, but temps will be falling for Wed evening into Wednesday night. Lows will be in the 30s for most spots, although far southern areas may only fall into the low 40s. The steadiest precip will be done on Thursday morning, however, some additional showers can`t be ruled out into the day on Thursday, as the remnant occluded front decays over the area and the departing surface low strengthens slightly as it exits off the New England Seacoast. P-type will likely be variable, with just rain showers for valley areas, but a wintry mix, including snow for the high terrain. The highest coverage of precip on Thursday looks to be across western New England, but even there, the additional amounts look very light, with under an inch of snow/sleet and just a trace of ice. Rainfall amounts looks light too and most of the time will just be dry. Most areas will be seeing steady temps in the 30s, although southern areas will still be topping out in the low 40s, but clouds remaining in place through the day. A few lingering rain and showers will still be around on Thursday night as the upper level trough starts to approach. Any precip looks light and spotty, but it will remain cloudy across the entire area with temps mainly in the 30s (some upper 20s across the Adirondacks and Greens). && .LONG TERM /FRIDAY THROUGH TUESDAY/... Moderate to high confidence in the overall temperature pattern as forecast models/ensembles continue to suggest a warmer than normal pattern regime continuing through the long-term period with higher geopotential heights and a mean H500 flow that`s flat (semi-zonal) over the region. With average high/low temperatures January 6-10th in the lower 30s/mid teens, respectively, forecast high temperatures will be on the order of 5F-10F degrees above normal with values near the 40F degree mark each day. Meanwhile, low temperatures will be on the order of 10F-15F degrees above normal with values in the mid 20s to lower 30s during this period. As far as precipitation, there`s less certainty due to the large model spread in the handling of several weak perturbations in a split- flow regime tracking over the region that could trigger clouds and precipitation. There still remains quite a bit of uncertainty in the precise northern/southern stream tracks and magnitude of these weak impulses. We start off the long-term period on Friday with a weakening double barreled low pressure system with the primary low off the New England Coast and a weakening secondary surface low and associated upper low approaching the region. Scattered precipitation (mainly valley rain/mountain snow showers) will be taking place Friday morning. These showers could continue into the afternoon hours before waning in coverage and intensity Friday afternoon/evening as the low departs to our east. The could be some lake effect snow showers impacting our northwest zones Friday afternoon/evening into Saturday as the low departs. A 1025-1032 mb Canadian surface high to our northwest is expected to build into the region on Saturday bringing dry weather to much of the area. Forecast uncertainty increases Saturday into Sunday as a vigorous shortwave/developing low pressure system develops over the Ohio Valley and tracks east. At this time, most models/ensembles has the aforementioned Canadian high deflecting the approaching storm system to our south. This keeps the area precipitation free Saturday evening into Sunday. Because of the uncertainty in the track of this next storm system, have just low grade PoPs (20%) over the area Saturday evening into Sunday. Beyond Sunday, the pattern looks mainly dry. However, will have to watch for yet another storm system or two (one to our north attached to the northern stream and another to our south attached to the southern stream). Some models are projecting/signaling these disturbances to impact our area Sunday night into early next week while others keep the area dry. Have kept things dry for now until things become more apparent. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Through 00z Thursday....MVFR to LIFR conditions due to a combination of rain, drizzle, low stratus, mist, and/or fog as a warm frontal boundary stalls over the region is expected to persist through the entire 00z TAF cycle. As of this update, conditions are ranging between MVFR at KGFL to LIFR at KPSF with cigs between 300-1800 feet AGL and visibilities between 3/4 and 8 statute miles. Latest radar reflectivity shows the first batch of rain showers east of the Hudson River Valley and pushing east with fragments of light rain showers or drizzle from the I-87 and points west. The expectation is that for tonight any rain showers will taper off to drizzle with a continuation of low stratus and mist/fog. Overnight into Wednesday morning, a BKN-OVC deck of low stratus with mist/fog will continue with patches/areas of drizzle. The second batch of rain is expected to arrive Wednesday afternoon/evening between 20z-24z. Winds are expected to remain calm through the 00z TAF period. Low level wind shear could be a problem at KPOU amid the calm surface winds with winds 2 kft AGL 35-40 kts out of the southwest. Outlook... Wednesday Night: High Operational Impact. Definite RA. Thursday: Moderate Operational Impact. Chance of RA. Thursday Night: Moderate Operational Impact. Chance of SHRA...SHSN. Friday: Moderate Operational Impact. Chance of SHRA. Friday Night: Low Operational Impact. Slight Chance of SHRA. Saturday: Low Operational Impact. NO SIG WX. Saturday Night: Low Operational Impact. Slight Chance of SHRA...SHSN. Sunday: Low Operational Impact. Slight Chance of SHRA...SHSN. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...Frugis/Wasula NEAR TERM...Frugis/Wasula SHORT TERM...Frugis LONG TERM...Evbuoma AVIATION...Evbuoma
Area Forecast Discussion
National Weather Service Binghamton NY
927 PM EST Tue Jan 3 2023 .SYNOPSIS... A stalled out front across central New York will keep spotty showers around tonight into Wednesday morning, with a second bout of steadier rain expected Wednesday afternoon. Unsettled weather will continue through the remainder of the week, and some wintry precipitation may return by Friday. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... 915 PM Update... Showers developed across PA since the last update, so PoPs were increased across NEPA and the Catskills. Some breaks in the rain showers are present in portions of CNY, especially west of I-81. Some minor adjustments were made PoPs into the overnight hours, mainly relying on NBM and past forecast as the CAMs vary from solution to solution. These showers will continue through the overnight and eventually move out early Wednesday morning. Some minor adjustments were needed to hourly temperatures as well to better match observations. An SPS was issued earlier for fog in Pike (PA) and Sullivan (NY) Counties as visibilities had dropped as low as 1/4 mile. That will be evaluated at the top of the hour if another is needed. Fog remains present across the region. Latest observations show that the valley around Elmira has also dropped to 1/4 mile. Patchy areas of low visibilities will remain possible over the next few hours. Then there may be some improvements though fog will remain present. 600 PM Update... Showers continue to move through the region, though activity is more isolated across NEPA and the Catskills. With less activity south of the Southern Tier and not much to the west on the regional radar mosaic, PoPs were lowered in the southern half of the region. It seemed like the HRRR has been handling this the best, so that was blended in with the previous forecast. This does keep higher PoPs across CNY through the evening, which is also supported by most of the CAMs. Patchy fog was added for more areas based on the visibility forecast that is used for the TAFs. Forecast soundings are saturated in the lower levels throughout the night. Conditions may improve some once the showers move out. Some minor adjustments were needed for the hourly temperatures as well. Observations in Oneida County are reporting 30s. The northern portions of the Finger Lakes are also slightly cooler than forecasted. Conshort and ADJLAV were blended with a little bit of the NAMNest to get the forecast closer to what the obs were reporting. Previous Discussion... Light Rain showers continue across the area this afternoon with some moderate showers moving into the Finger Lakes. The warm front has stalled out over central NY, with upper 40s to low 50s across the southern Finger Lakes, Southern Tier and NEPA. Low 40s are present across the northern Finger Lakes extending into the Mohawk Valley and Tug Hill. Looking at the overall picture, a stacked low is currently sitting over Nebraska and Iowa, very slowly drifting to the NE. A shortwave was ejected from the low and pushed into our region this morning, initiating the rain showers. This shortwave is slowly exiting our region to the east and south, taking the strong upper level forcing with it. The warm front will morph into a quasi-stationary front this evening and into tomorrow, continuing to sit across central NY. Mid-level winds will flow almost parallel to this front, allowing for isolated rain showers to develop across NY tonight. Continued WSW flow through the overnight hours will keep lows very warm, only dropping a few degrees from todays highs and almost 30 degrees above normal south of the front. Mid 40s to low 50s are expected here while north of the front, upper 30s to low 40s are expected. A brief lull in the rain showers is expected Wednesday morning as some drier air moves across the region. Another shortwave and associated surface low is expected to eject from the parent stacked low over the upper midwest, bringing another batch of rain showers Wednesday afternoon through late Wednesday night. This surface low will move through the Ohio River valley and into western NY, keeping the CWA in WAA through Wednesday evening. The stationary front will keep the thermal gradient in a somewhat similar place as Tuesday. Warmer temperatures are expected south of the front across the southern Finger Lakes, Southern Tier and NEPA, with highs in the mid 50s to low 60s. North of the front, mid 40s are expected. As the low moves north and east of the region, it will kick the stationary front east and pull a cold front through the area, continuing rain shower chances through the overnight hours. Temperatures will slowly cool Wednesday night from west to east, with NY areas in the upper 30s to low 40s and NEPA and the southern Catskills in the mid 40s. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... 335 PM update... Main concerns in the short term are focused on the lingering rain showers expected Thursday with the potential for some light freezing rain possible in northern Oneida County Thursday night...with a transition to a mix of rain and snow during the day Friday and lingering snow showers Friday night. Low pressure system rolling east across the Great Lakes will have a weakly amplifying ridge out ahead of it across the Northeast that will have a wedge of drier air associated with it and allow for a period of relatively dry conditions early on Thursday. The stationary front draped across the northern counties will lift farther to the north and the warm, dry air will shift eastward through the day. The southwest flow in the mid and upper levels should keep the high terrain light the form of rain...going into the early evening hours. Stronger forcing associated with the upper low will arrive Thursday night and Friday morning in the form of mostly a rain/snow mix for the low elevation and valley locations, but generally light snow for areas above roughly 1400 ft. Could see around a half inch in the hills south of Syracuse and into the western Catskills. There is a narrow window for some light freezing rain across northern Oneida County Thu night as the warm nose aloft is undercut by the cold temperatures coming in from the west. The probabilities look even less than before, and confidence is low, so have keep with just a slight chance of freezing rain. The cold air makes a stronger push to the east behind the departing system which will cause a change to all snow by the late afternoon/evening time frame. A steady west/northwest flow will set up in the boundary layer and cause some lake effect snow showers to be generated across central NY through Friday night. Accumulations at this time look to be fairly light. Mild temperatures are expected Thursday with highs topping out in the 40s to around 50. Overnight lows Thu night/Fri morning will bottom out in the 30s...before recovering into the mid 30s to near 40 on Friday and then drop back into the upper 20s and lower 30s Friday night. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 335 PM update... Positively tilted, weak, low-amplitude upper trough across the Great Lake into the Ohio Valley will drag slowly eastward across the Northeast US this weekend and trigger some precipitation over central NY and ne PA Saturday into Sunday. This system is expected to produce light snow, mixed with some light rain in the valleys and low elevation areas during the day Saturday before the slightly colder air moves in Saturday night and Sunday...changing lingering rain over to snow. Boundary layer temperatures will hover around or just above freezing with a fairly cold layer aloft which will allow for mostly snow for the region, but potentially melt some snow around the flakes in areas that see temperatures in the upper 30s and lower 40s. At this time, any light snow accumulations in the higher elevations should be limited to an inch or less. Temperatures drop into the 20s to around 30 Saturday night and only climb into the 30s for most of central NY to near 40 in the Wyoming Valley in PA Sunday. There may be a weak lake effect potential that could continue into Monday morning off of Lake Ontario, but confidence is not there yet, so will keep with mostly dry weather Sunday night and Monday with temperatures down into the 20s in the morning and back into the 30s to near 40 Monday afternoon. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... 645 PM update... Rain over ITH/SYR/RME will taper off to spotty showers by 05z. Steady rain will move in around 17z Wednesday at all sites continuing through 00z. All sites will remain MVFR/IFR through 00z Thursday. Rain will cause IFR vsbys as well as higher terrain at BGM for the overnight. Cigs will lower into the IFR category this evening at all sites. Cigs lift to MVFR Wed morning at ELM/AVP then fall back to IFR when the rain returns. BGM/ITH could have cigs near airport minimums late tonight. With a warm front over the area winds are light and will remain that way. East winds at SYR then south to southeast further south in NY and southwest at AVP. Outlook... Wednesday night...MVFR/IFR restrictions likely. Thursday and Friday...MVFR and VFR with low chances for rain or snow showers. Saturday...Mainly VFR; low chance for lake effect snow showers and associated restrictions at RME and SYR. Sunday...VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...JTC/MPH NEAR TERM...BTL/JTC SHORT TERM...BJT LONG TERM...BJT AVIATION...TAC
National Weather Service Bismarck ND
931 PM CST Tue Jan 3 2023 .UPDATE... Issued at 928 PM CST Tue Jan 3 2023 Have now added the remainder of the southwest into the dense fog advisory as the western edge of the fog has now started gradually moving west. High-res guidance indicates this trend should continue over the next few hours. UPDATE Issued at 750 PM CST Tue Jan 3 2023 Have added another tier of counties to the Dense Fog Advisory to the north and east side of the advisory as Rugby and Harvey have dropped below 1/4 mile, and Carrington has been hanging out at 1/2 mile. A look at the webcam by Medina also looks quite foggy. UPDATE Issued at 632 PM CST Tue Jan 3 2023 For early evening update about the only change was to spread widespread fog to the southwest. As mentioned before, the tricky part is wondering if we need to spread the advisory out, mainly to the southwest, but so for visibility has been holding up over that area. Will continue to closely monitor. && .SHORT TERM...(This Evening through Wednesday) Issued at 229 PM CST Tue Jan 3 2023 The main forecast issue in the short term period will be the ongoing dense fog. Latest satellite imagery shows fog continues to slowly dissipate this afternoon. However, there are enough sites with low visibility to continue the Dense Fog Advisory along the Missouri River. Will cancel northern and eastern portions of the Advisory, as well as for portions of southwest ND. Fully expect that the current advisory mainly along the Missouri River will need be expanded, but exactly when and how much areal extent remains a question. Will leave that for the evening and overnight shifts. Surface high pressure is situated over western and central ND and looks to remain through the short term period. RAP and HRRR guidance tend to be overdone with stratus/fog during the winter, but since it has a pretty good handle on the fog with this event, think they are reasonable with their fog depiction increasing again this evening and continuing into Wednesday. The storms system from the central Plains into Minnesota could lift and bring more clouds into the James River Valley which could help inhibit fog development here, but otherwise fog can be expected just about everywhere through Wednesday. Other than the low stratus and fog, the weather remains pretty quiet. Lows tonight will be mainly in the single digits to low teens with highs Wednesday in the mid teens to mid 20s. .LONG TERM...(Wednesday Night through Tuesday) Issued at 229 PM CST Tue Jan 3 2023 Fog concerns continue into the long term period. A warming trend looks to be in store late in the extended period. A weak upper level pressure pattern with a weak surface flow remains to begin the long term forecast period. On Thursday, a weak upper level wave slides southeast through central and eastern ND, but with little surface reflection, don`t think this will have much influence on our weather. After this we continue to see a series of storms impact the West Coast, with a general high over low upper level pattern over the central portion of the country. This would be indicative of a quiet weather pattern, but some potential fly`s in the ointment being low stratus/fog issues into the weekend. Building heights and a more progressive flow late in the period may bring some warmer temperatures our way. However, a large spread remains in the NBM ensembles so confidence is not overly great at this time. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 632 PM CST Tue Jan 3 2023 Widespread LIFR to IFR ceilings and visibilities are expected to continue through Wednesday morning. && .BIS WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until noon CST /11 AM MST/ Wednesday for NDZ009>013-017>023-025-031>037-040>047-050. && $$ UPDATE...JJS SHORT TERM...TWH LONG TERM...TWH AVIATION...JJS
Area Forecast Discussion...Updated
National Weather Service Billings MT
849 PM MST Tue Jan 3 2023 .UPDATE... Challenging fog forecast for SE MT tonight. High clouds were moving NW into the area from central plains, while Nighttime Microphysics showed broken areas of fog over N Rosebud County into Custer County with some fog or stratus developing over Powder River County. Some webcams showed dense fog such as Sweeney Creek and Ingomar...while KMLS visibility was up to 2 1/2SM. Decided to stay the course and leave the Dense Fog Advisory in place over Treasure, Custer, Fallon, and Northern Rosebud based on HRRR guidance. A vort max was nearly stationary over the S. Central part of the area with some radar echo that was likely just mid cloud based on nearby obs. Models showed a colder airmass moving in overnight, while a favorable pressure gradient for gusty winds remains in place over western areas. Forecast covered temps and winds well, except the Northeast Bighorns were at/near forecast lows, so have lowered temps there. Arthur && .DISCUSSION... Tonight through Wednesday Night... Fog remains the main issue over the next 24 hours. Visibility of a quarter mile continues to be reported at Miles City and Forsyth as of 130pm. Satellite imagery shows fog persisting along the Yellowstone as well as some other eastern valleys, and web cameras in northern Rosebud County remain quite foggy. We remain under we weak flow aloft with light easterly surface winds across our east. High res models continue to support dense fog across mainly our northeast from Rosebud to Fallon Counties thru the night. By Wednesday morning we will begin to advect drier air from the west and this should erode the fog for good. In the meantime, we have a dense fog advisory in effect for these areas thru 18z tomorrow. Satellite imagery shows departing low well to our east (moving into MN/IA), having undercut a region of high pressure centered over southern Saskatchewan. Upstream there is a shortwave approaching the Pacific coast, and a deeper trof further west. Overall theme is to increase the Pacific flow over the coming days. This will of course result in a warming trend for us. Other than some light snow showers over the mountains, the next 36 hours will be dry under slowly building heights. Temps will be seasonable. Look for highs on Wednesday in the upper 20s and 30s (coldest east where there remains some snow cover). Regarding wind, there appears to be a brief opportunity for Livingston to reach 50 mph gusts tonight into early tomorrow. Mid level winds do not appear to be strong enough for higher gusts than that so no need for a wind highlight...but high-profile traffic on I-90 should take note. JKL Thursday through Tuesday... Very quiet weather will continue into next week. The only exception to this is a weak shortwave which will bring some light snow/rain showers Thursday night and Friday. Main forcing tracks well to our south and latest model trends are drier for our region. Not much else to say. Looking across the Pacific we see an enhanced zonal jet across much of the Ocean, and this is leading to warm air pushing into all of western North America...a pattern that will change very little over the next week. There is an occasional weak/splitting shortwave embedded in the Pacific flow...thus periodic chances of light snow for our mountains. Otherwise, any chance of precip at lower elevations will remain quite low thru next Tuesday and likely beyond. Seasonable temps Thursday will climb to above normal for the the end of the week...where they will stay for an extended period of time. Look for highs generally mid 30s to upper 40s this weekend thru the middle of next week. Could see some 50s in there too. Looking for a return to something colder & snowier? You`ll have to wait til the second half of January, at least. There are signs of a disruption to the Pacific jet by the middle of the month, which could change the longwave pattern eventually. Stay tuned. JKL && .AVIATION... Areas of dense fog and low clouds causing VLIFR/LIFR conditions will continue across eastern Montana into Wednesday morning. This will impact KMLS and KBHK. Visibility will drop to a quarter mile or less at times. VFR conditions are expected in the rest of the forecast area. Conditions will improve to VFR for the entire forecast area by Wednesday afternoon as the fog lifts. Archer/TWH && .PRELIMINARY POINT TEMP/POPS... Wed Thu Fri Sat Sun Mon Tue ----------------------------------------------------------- BIL 021/037 020/036 026/043 027/045 026/043 027/045 026/045 00/U 00/B 14/W 10/U 00/B 01/B 01/B LVM 020/034 020/041 029/043 026/043 026/042 027/042 026/045 00/N 01/N 22/J 00/U 01/B 11/B 12/W HDN 012/035 009/033 018/039 021/041 017/040 019/041 017/042 00/U 00/B 14/W 10/U 00/U 00/B 00/B MLS 010/028 007/028 013/029 016/034 014/034 016/034 016/034 00/F 00/U 02/J 10/B 00/U 00/B 00/B 4BQ 015/035 012/034 018/036 023/040 019/041 019/041 020/044 00/U 00/U 02/J 10/B 00/U 00/B 00/B BHK 010/028 009/028 012/028 013/032 017/034 016/033 017/034 00/F 00/U 01/B 00/B 00/U 00/B 00/B SHR 013/035 012/036 020/038 022/041 018/041 021/041 019/042 00/U 00/B 14/W 20/B 00/U 01/B 00/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Dense Fog Advisory in effect until 11 AM MST Wednesday FOR ZONES 30>33. WY...None. && $$
Area Forecast Discussion
National Weather Service Columbia SC
819 PM EST Tue Jan 3 2023 .SYNOPSIS... Moisture will increase across the region through Wednesday with showers along with possible thunderstorms expected ahead of a cold front. Fair and cooler conditions Thursday into the weekend behind the cold frontal passage. && .NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/... Showers moving into the western portion of the forecast area this evening. While convection earlier today generated by an upper shortwave in central GA was strong to severe at times, with a loss of daytime heating and a more stable airmass in place over the forecast area, storms have continued to weaken, denoted by warming cloud tops on IR satellite imagery. While temperatures across the area have cooled by around 10 degrees from the high, not expecting much more cooling for the rest of the night with thick cloud coverage moving in and increasing winds in the boundary layer out of the SW. Lows generally in the low 60s tonight. Upper ridging will continue to break down over the area with some cooling aloft which will lead to at least weak elevated instability. This should be able to maintain at least a chance of thunderstorms in the forecast area. GOES GLM continues to show lightning with the convection moving into the area from the west but the coverage has decreased significantly. Still think occasional strikes will be possible through early tonight. By late tonight into early Wednesday morning, recent HRRR runs (00z runs of other HiRes models are still coming in as of writing this) are indicating a break in coverage of showers and storms. This trend will need to be watched closely as the earlier this break occurs, the better chance for surface destabilization ahead of the line storms associated with the cold front Wednesday. && .SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... Cold front will continue to track eastward from western Ga early in the day. Upper flow pattern at 250mb remains mostly difluent throughout the day ahead of the front, with stronger jet pushing towards the cwa by the afternoon. Showers and storms are expected to be ongoing Wednesday morning along both a prefrontal trough and along leftover surface boundary from the overnight hours across the southern portions of the cwa. Convection early in the day may not be surface based, but more elevated with limited instability due to weak lapse rates. Better chance for more organized convection should occur during afternoon just ahead of the main advancing cold front. There will be a good amount of shear in the lower levels with a strong 850mb jet moving through. While a widespread severe threat remains limited, can not completely rule out an isolated severe storm ahead of the front. With limited instability and stronger shear, winds or tornadoes continue to be the main concern if a strong storm takes hold. SPC continues with a Marginal risk for the majority of the cwa, with a Slight Risk barely nudging into the western CSRA. Once the convection and the front move through Wednesday evening, drier conditions will filter into the cwa overnight and into Thursday. Temperatures Wednesday are forecast to reach the 70s again, but may be highly dependent on cloud cover and rainfall. Lows Wednesday night down to around 50. Cooler air may be a little slow to move into the area on Thursday, and with a good amount of sunshine expected, highs should reach the mid to upper 60s in most areas. By Thursday night, cooler air will have taken over, allowing overnight lows down in the upper 30s to the lower 40s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Not really a lot of change to the longer term thinking. As the deeper upper trough moves through the Mid-Atlantic and the Southeast, drier and cooler air will continue through Saturday night. Another approaching upper trough will begin to influence the pattern by Sunday, bringing the next chance for rainfall to the area. Moisture may still be limited, so pops mainly slight chance into early next week. Temperatures close to normal through the period. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... Periodic restrictions expected this evening with showers and isolated thunderstorms, with more widespread restrictions at all terminals late tonight into Wednesday morning. VFR conditions continue for another hour or two at the Augusta/Columbia terminals, and slightly longer at OGB. BKN-OVC CIGS are expected to decrease as -SHRA and ISOLD TSRA move into the region from west to east. Rainfall may be heavy at times with periodic VSBY restrictions. Confidence in thunder remains too limited to include in the TAFs. The main area of precip should be east of the terminals by 04/09-04/11z, with VCSH continuing thereafter through much of Wednesday morning. Moisture will continue to rapidly increase with a high likelihood of IFR cigs returning through mid-morning tomorrow or later, when MVFR cigs are expected immediately ahead of a cold front. Another line of SHRA/TSRA is then expected to move through the area early Wednesday afternoon. SFC winds generally light from the S/SW tonight into Wednesday, with stronger SW winds 10-15 kts with gusts to 25 kts late Wednesday morning through the afternoon. NOTE: The KAGS observation is not available in or unrepresentative of current conditions at night when an observer is not present. This has led us to include AMD NOT SKED there and we`ll keep it in there until further notice due to a communications outage. EXTENDED AVIATION OUTLOOK... Showers become more numerous during the day on Wednesday, including the possibility of thunder through the afternoon. Behind a frontal passage later Wednesday, conditions should improve and restrictions are expected to lift at all terminals. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION...
Area Forecast Discussion
National Weather Service Grand Rapids MI
954 PM EST Tue Jan 3 2023 LATEST UPDATE... Update .UPDATE... Issued at 946 PM EST Tue Jan 3 2023 There could be a few stronger storms over the next 2 hours as instability continues to advect in from the southwest. Deep layer shear is supportive of organized convection. Model forecasts show the instability to decrease as it advects in...however given the current growth of the cells on appears some of the storms will contain small hail. A tight frontal zone existed along I-94. As the 30 knot low level jet crosses this frontal zone...continued thunderstorm development should occur. So we will maintain the risk for thunderstorms for the next couple of hours. UPDATE Issued at 519 PM EST Tue Jan 3 2023 The potential for thunderstorms was increased and brought in sooner with the forecast update. Radar trends show an area of showers and thunderstorms over Southern Lake MI tracking northeast. They appear to have enough momentum to potentially move into the Muskegon to Grand Rapids area between 700 pm and 800 pm. Then for the remainder of the night...the steeper mid level lapse rates advect in from IL and IN during the evening hours. A 30 knot low level jet also moves into Southern Lower MI. These two features will help to maintain a risk for at least a few storms...and increase the potential for small hail. && .DISCUSSION...(This evening through next Tuesday) Issued at 315 PM EST Tue Jan 3 2023 --Dense Fog Threat Tonight and Wednesday Morning-- Sfc warm front is still located just south of the MI/IN border but expected to make some northward progress tonight before becoming a triple point/occlusion overhead on Wednesday. Sfc dew points are in the upper 50s just south of the front and the arrival of a juicier air mass and lighter winds/baggier pressure gradient from the south tonight will set the stage for at least areas of dense fog, if not widespread. One limiting factor this evening for dense fog is the potential for a decent batch of showers (and perhaps even isolated tstms) to come through, which would temporarily mix out the lower visibilities. This would be associated with the lobe/spoke of vorticity currently heading northeast from IL, which also represents the leading edge of the mid level dry slot. RAP continues to show 500-800 J/KG MUCapes arriving in srn Lwr MI after 22Z/5PM ahead of this feature so a clap of thunder is certainly a possibility. After passage of the mid level shortwave around 06Z tonight, the dense fog potential should be on the increase and an advisory may be needed to cover the Wednesday morning commute period. Confidence in location/coverage of the densest, most persistent fog is currently too low to issue a headline. Visibilities are expected to slowly improve by Noon Wednesday. --Light Snow/Rain Mix Wednesday Night and Thursday-- As the upper low over Iowa slowly meanders in our direction the next few days, periodic light precip will persist within moist cyclonic flow pattern. Colder air aloft arrives from the west/southwest on Wednesday night which eventually changes the scattered rain showers over to snow showers or a rain/snow mix. Minimal travel impacts expected as any snow accumulations should be under an inch and sfc temps look too marginal to support much of a freezing rain or drizzle threat. --Mild/Tranquil Pattern over the Weekend-- The upper low moves away on Friday although upper troughing and the cold air aloft lingers into Friday night. This could support some lingering light precip, but surface ridging is shown to eventually build in over the weekend. Actually it looks like some sunshine potential exists for Sunday and Monday which has been an extreme rarity over the last month or so. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 627 PM EST Tue Jan 3 2023 Earlier we updated several TAF sites to add some thunder to the forecast. With this issuance we expanded the thunder mention and added a few more hours. One batch of storms was rolling northeast through KMKG and almost into KGRR. Those will not last long as they are moving quickly. We should see a break for an hour or two..but the next round of storms is already developing in IL. These storms should continue to expand as they track northeastward into Southwest Lower MI. They will be around for a few hours this evening before moving away from the TAF sites by midnight. IFR and lower conditions will prevail for most of time through 18z. After 18z Wednesday...there are some indications that we could see conditions going to MVFR as slightly drier air advects in from the west. We did feature an improving trend to the ceilings and visibilities during this timeframe. && .MARINE... Issued at 315 PM EST Tue Jan 3 2023 Will cancel the Small Craft Advisory early since stronger east winds north of the warm front never really materialized. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ UPDATE...MJS DISCUSSION...Meade AVIATION...MJS MARINE...Meade
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
958 PM EST Tue Jan 3 2023 .SYNOPSIS... Widespread rainfall and possible thunderstorms are expected to develop from the west late today and persist through Wednesday as a cold front sweeps east across the region. Drier and cooler conditions return by the end of the week. Increasing cloud cover and low precip chances return by the weekend. && .NEAR TERM /THROUGH WEDNESDAY/... As of 935 pm EST: A wide band of showers and embedded thunderstorms driven by a lead short wave continues to work its way east across the Upstate and western Piedmont this evening, with the radar mosaic showing less coverage over the mtns. This appears to be the lull in the action to which the day shift expected. Precip probs will be adjusted accordingly. Still a few lightning strikes in the activity across the eastern zones in a lingering band of weak most-unstable CAPE of around 250 J/kg. Our severe chances are very low for the next few hours, but may ramp up from the west and southwest as we get on toward daybreak Wednesday as suggested by the most recent run of the RAP showing air mass recovery and destabilization ahead of the front working its way in from the SW. Temps are in need of adjustment based on the evolution of the widespread precip. Otherwise...a deep mid-level vortex is expected to stall over the upper MS River basin tonight and Wednesday. A vigorous cold front stretched south of this system along the length of the Mississippi River. This boundary will make steady progress eastward toward the southern Appalachians through tonight, driven forward by a pair of strong short waves rotating through the upper trof, before crossing the region through Wednesday. After our brief lull into the early overnight, discrete coverage is expected to pick up through the morning hours east of the mountains, and a wider upslope and frontal focus should develop near the southern mountains. Hydro concerns will ramp up steadily through daybreak, but flooding issues should be isolated enough to avoid a Flood Watch. Any flooding associated with training cells will be harder to pin down through Wednesday, and a Marginal risk of excessive rainfall will be possible just about anywhere until the front passes. The approaching cold front will reach the spine of the southern Appalachians late Wednesday morning and then cross the region through late day. The 18Z run of the NAM shows a favorable overlap of 500-1000 J/kg of sfc-based CAPE and deep layer shear on the order of 45 kt...which is corroborated by the 21Z RAP. Hodographs elongate in the morning with the passage of a 50+ kt low level jet, and look...compelling. As we like to say...we`ve done more with less. The Day 2 Convective Outlook shows Marginal east of the mtns, but the previous run of the HREF and subsequent HRRR runs have shown some rotating storms along/S of the I-85 corridor through the morning and early afternoon, so it might be best to anticipate a better severe storm risk for Wednesday. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 100 PM EST Tuesday: The trailing cold front associated with a stacked occluded low over the northern Great Plains and Upper Great Lakes region will be in the midst of making a full fropa across the CFWA by the start of the forecast period as any lingering precip in the eastern zones should come to an end by Thursday evening. Dry conditions will be in store as surface high pressure gradually builds in as it slides across the Lower MS Valley and Deep South through the short-term. Temperatures on Thursday will remain 5- 10 degrees above normal as a downslope component will offset any post-frontal cooling. With the axis of the stacked low lifting out of the area Thursday night into Friday, northwest flow will begin to filter in. Upper forcing from the passing vort lobe on the base of the lifting upper trough and just enough cold air and low-level moisture should promote the development of a few NWFS showers along the TN border in the favorable upslope locations. Accumulations will be very light, but the overall ingredients don`t support a more significant event. High pressure remains in control through the end of the work week as deep layer northwest flow pushes into the area late Thursday into early Friday. This will support a dropoff in temperatures by Friday to more seasonal values as weak CAA settles in. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 230 PM EST Tuesday: The pattern becomes more uncertain in the extended period. Model guidance currently overlays quasi-zonal flow aloft over the region with embedded shortwaves traversing within this regime for much of the forecast period. Sporadic areas of forcing could lead to mentionable PoPs over the weekend into early next week as a weak low pressure system develops over the mid-MS Valley and travels eastward. This will bring on and off chances of light precip across the area, especially over the High Country. Thermal profiles are too warm to support anything other than rain outside of the ridgetops. Good consensus with drier weather being in store for the D6/D7 time period. Temperatures will generally run near-normal for much of the period, with some variability due to precip chances and cloud cover. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: Grim aviation weather for the next 12-18 hours with widespread IFR to LIFR ceiling and MVFR/IFR visibility in waves of rain and embedded thunderstorms. There will be MVFR/VFR holes in this activity, with still a decent chance for an overnight lull in the precip activity, but the IFR or worse will prevail. Wind will be mainly S to SW away from convective storms. Models indicate another round/wave of convection that will organize to the west overnight and then move eastward across the fcst area from daybreak through mid afternoon. The convection will bring an improvement to IFR and MVFR along with a good chance of thunderstorms that should affect mainly the Upstate terminals and KCLT. A PROB30 was employed to indicate a 6 hour time period when the storms are most likely to cross the region. An isolated severe storm will not be ruled out. Wind will be gusty from the SW. Rapid improvement will occur as an effective cold front crosses the region in the mid to late afternoon. All terminals should become VFR by sunset. Outlook: VFR with dry conditions return by Thursday and continue into Saturday. Another moist low pressure system could affect the region late in the weekend. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...CAC NEAR TERM...HG/PM SHORT TERM...CAC LONG TERM...CAC AVIATION...PM
Area Forecast Discussion...UPDATED
National Weather Service Hanford CA
444 PM PST Tue Jan 3 2023 .UPDATE...Updated AIR QUALITY ISSUES section. && .SYNOPSIS...Active weather continues for at least several more days. A break in the rain today will eventually lead to a strong storm system impacting the area Wednesday morning into Thursday evening. On Friday, calmer weather is expected before another low pressure system arrives into the area Saturday. && .DISCUSSION...Calmer weather and warmer temperatures are prevailing today, before tomorrow’s activity. On Wednesday morning, a warm frontal surge will bring light to moderate precipitation into our area with showery conditions continuing later in the afternoon. From late Wednesday evening into Thursday a strong (150+ kt at 250 mb) jet will position itself at a favorable position for some dynamic lifting to be associated with the second punch. This will result in strong winds across downslope prone portions of our CWFA. The 18Z HRRR model indicates high winds in the San Emigdio and Tehachapi Mountains with sustained winds reaching 40 to 50 mph and gusts approaching 95 mph. Combined with low visibility, treacherous travel is a concern at the Grapevine/Tejon Pass. A High Wind Warning has been issued for this part of the forecast area between 400 am PST Wed and 400 am PST Thu. In addition, increased downslope winds are expected along the West Side Hills and in the south end of the San Joaquin Valley with sustained winds reaching 20 to 30 mph and gusts approaching 55 mph. As the cold front approaches on Wednesday night and Thursday morning, it will bring moderate to heavy precipitation and high elevation snowfall. A Flood Watch is in effect for the entire CWFA except the Kern County Deserts and the higher elevations of the Sierra Nevada from 400 am PST Wednesday until 400 am PST Friday. With the anticipated rainfall from the incoming system combined with saturated soil from previous rainstorms, this could lead to another round of widespread nuisance flooding and the potential for rock slides. A Winter Storm Warning remains in effect for the high elevations of the Sierra Nevada. The forecast include 6 to 18 inches of new snow above 5000 feet and 2 to 4 feet of new snowfall above 7000 feet. Another concern with this system is that with post-frontal unstable airmass over central CA on Thursday afternoon, thunderstorms will be possible across the San Joaquin Valley, West Side Hills and Sierra Nevada foothills. The Storm Prediction Center is showing a marginal risk of severe thunderstorms in the western half of the San Joaquin Valley and over the West Side Hills by Thursday afternoon. A lull in activity is expected for Friday before an approaching low pressure system affects our region on Saturday. This storm system is expected to be drastically weaker. Afterward, a potentially strong storm system will have to be monitored closely for potential impacts across our area next Monday and Tuesday. The Climate Prediction Center continues to show chances of above average precipitation across the entire state of California 6 to 10 days out. This combined with heavy Sierra Nevada snowfall will lead to a wet first half of January. && .AVIATION...Increasing MVFR conditions with areas of mountain obscuring IFR conditions will become prevalent across the Sierra Nevada and adjacent foothills by 15Z Wed. Obscuring IFR and possibly LIFR conditions in low clouds and precipitation will be focused for the Sierra Nevada and Tehachapi Mountains and the adjacent foothills and valley facing slopes. Areas of MVFR in rain and low clouds over the San Joaquin Valley after 12Z Wed. Elsewhere, VFR conditions will prevail across the central CA interior for the next 24 hours. && .AIR QUALITY ISSUES...On Wednesday January 4 2023,Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno and Kern Counties. Burning Discouraged in Kings, Madera, Merced, and Tulare Counties, and Kern (Greater Frazier Park Area) and Sequoia National Park and Forest. && .CERTAINTY... The level of certainty for days 1 and 2 is medium. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... Flood Watch from 4 AM PST Wednesday through late Thursday night for CAZ300>327-329>336-338. Wind Advisory from 4 AM Wednesday to 4 AM PST Thursday for CAZ300-304-308-313-316. Winter Storm Warning from 7 AM Wednesday to 4 AM PST Friday for CAZ323-326>330. High Wind Warning from 4 AM Wednesday to 4 AM PST Thursday for CAZ334>336. && $$ public...Chamberlain grids/aviation/fire wx...DAS pio/idss...BS
Area Forecast Discussion
National Weather Service Lincoln IL
823 PM CST Tue Jan 3 2023 .SYNOPSIS... Issued at 243 PM CST Tue Jan 3 2023 Scattered showers and thunderstorms are possible west of I-55 through Tuesday evening. A few storms could be strong to severe. It will be much cooler on Wednesday, with high temperatures returning to near normal, in the upper 30s. Scattered flurries or light snow will be possible Wednesday afternoon through Thursday, primarily north of I-74. && .UPDATE... Issued at 822 PM CST Tue Jan 3 2023 At 8pm this evening, a cold front was located roughly just east of the I-55 corridor and will continue east across the remainder of central and east central Illinois clearing the forecast area by 1 or 2 AM. A few spotty showers remain ahead of the front, most notably over northern Champaign and Vermilion Counties, but also an isolated cell southwest of Effingham. These should diminish or move out of the area over the next couple hours with dry conditions expected the remainder of the night. Based on earlier reports, it`s possible that 5 tornadoes touched down during storms this afternoon/evening and will be sending out a survey crew Wednesday morning to confirm. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 243 PM CST Tue Jan 3 2023 As of 2PM, visible satellite imagery showed mostly sunny skies across E MO and west-central IL, aside from diurnal cumulus. Records are falling across the area as temperatures soar into the mid-60s. Areas along and east of I-57 were still overcast, but the corridor of clear skies should pivot eastward this afternoon resulting in at least some sun. A dewpoint gradient is present across the CWA, with dewpoints decreasing with westward extent from I-55. Despite the latest RAP mesoanalysis showing 1000 J/kg of uncapped CAPE, vis satellite shows limited vertical extent to any of the diurnal cumulus across our area at the moment. Updrafts look a little more vigorous across SW IL as of 230PM. With sunshine prevailing and a slight increase in upper level forcing expected this afternoon, still anticipate shower/t- storm development within an hour or two. Much of the thinking regarding hazards has not changed since the early morning and mid-morning AFDs. There is a low, but non-zero, tornado potential. RAP analysis is in line with forecast soundings in showing 100+ J/kg of 0-3km CAPE in the vicinity of the sfc boundary, but the low-level wind profile appears largely unidirectional, with the KILX VWP hodograph showing no curvature and RAP analysis showing less than 100 m2/s2 SRH in the lowest kilometer. Small hail and damaging wind gusts look like more relevant concerns with any stronger updrafts this afternoon. Showers and storms may linger east of I-57 through 9 PM, then the rest of the night will be dry with cooling temperatures overnight. By Wed morning, the upper low will be positioned near the MN/IA border. A much cooler airmass will advect into the area behind the cold front, with 850mb temps falling to around -5 degC, a drop of nearly 15 degC in 24 hours. Expecting highs to only be in the 30s west of I-57, and while that`s right in line with typical temps for early Jan it will feel much cooler after the record setting warmth on Tues. With sfc winds of 10-15 mph, it will feel even cooler, with wind chills in the 20s through the day. It will be mostly cloudy on Wed. Steep low-level lapse rates and a shallow layer of instability atop the boundary layer could result in scattered flurries or light snow, primarily north of I-74 beginning Wed afternoon. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 243 PM CST Tue Jan 3 2023 Main forecast highlights through early next week include: 1) Cloudy and seasonable on Thurs, with isolated flurries or light snow across the northern half of the area. 2) The next chance for measurable precip is Saturday, in the form of a mix of rain and snow. 3) Dry with slightly above normal temps Sun into early next week. Thurs looks quite similar to Wed: cloudy with seasonable temps, modest westerly winds, and a chance for flurries or light snow across the northern half of the CWA as the upper low swings through N IL. By Fri, the upper low will have shifted off to the NE, and a sfc high pressure ridge builds into the Midwest, resulting in lighter winds and perhaps some breaks in the clouds. By Fri night, the next shortwave of interest is expected to be emerging over the central Plains. An associated sfc low develops and leads to precip across central IL on Sat. Rain and snow both appear possible at this time, though it`s somewhat difficult to discern between the two as both sfc temps and wet-bulb temps are currently forecast to be in the mid-30s, and the specific values will likely change depending on the exact track of the sfc low. Forecast soundings do not show much signal for mixed precip at this time, except for perhaps a chance of freezing rain/drizzle as precip winds down and cloud ice is lost. But confidence in that occurring is not high, so kept any mention of freezing rain out of the forecast. Ensemble members suggest QPF amounts of a few tenths are possible with this system, but there is currently not a signal for anything more than minor snow accumulations, if that. Behind that system, sfc high pressure builds in and should result in several days of dry weather across central IL, along with slightly above normal temps into early next week. Models show a disturbance moving through the southern Plains and mid-MS Valley Sun night into early next week, but current indications are that it should track far enough south to keep precip away from our CWA. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 518 PM CST Tue Jan 3 2023 A cold front is sweeping across central Illinois this evening. Scattered showers and storms are occurring near the front and will end as southerly winds veer to westerly behind the front. West winds will gust to around 20 kt behind the front and conditions should return to VFR for several hours before cold air stratocumulus develops resulting in MVFR ceilings that last the remainder of the period. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Deubelbeiss SYNOPSIS...Erwin SHORT TERM...Erwin LONG TERM...Erwin AVIATION...Deubelbeiss
Area Forecast Discussion
National Weather Service Indianapolis IN
957 PM EST Tue Jan 3 2023 .Forecast Update... Issued at 957 PM EST Tue Jan 3 2023 Thunderstorm activity in Illinois has diminished quite a bit in the past couple of hours. However, there are still some showers and embedded thundershowers along the front. Some activity is starting to pop up in southern Illinois and western Kentucky, and this may propagate downstream into Indiana as the night goes on. Trimmed PoPs in the immediate near term and confined them to the timing of the cold front, as any showers or storms will be along this boundary. Latest HRRR and RAP runs tend to agree with this idea. SPC mesoanalysis shows a lingering pocket of up to 500J/Kg MLCAPE across our western and northwestern counties. Therefore kept a mention of thunder for a few more hours until instability wanes. Elsewhere in the forecast, made minor adjustments to wind and temperature to reflect latest observations. Otherwise, forecast remains on track. && .Short Term...(This evening through Wednesday) Issued at 259 PM EST Tue Jan 3 2023 * Scattered showers and a few thunderstorms possible late today/tonight. Isolated severe cannot be ruled out mainly west. * Warm rest of today and tonight, temperatures falling Wednesday in wake of the cold front. Currently across the larger region, an area of low pressure is located across western Iowa, with a stationary front extending eastward across northern Illinois and Indiana, and a cold front extending southward just west of the Mississippi Valley. Much of the warm sector has remained socked in with low stratus today, which has limited insolation and allowed advection to dominate warming processes today. There is a clear slot just ahead of the front with an area of low level convergence along the backside of the stratus deck. Some very modest instability has developed in this area, and CAMs have pretty consistently developed some scattered convection in this area late this afternoon into early evening. They have backed the timing up slightly which appears reasonable given the earlier more aggressive runs and the minimal initiation thus far. Do expect a few showers and perhaps isolated-widely scattered thunderstorms to develop over the next couple of hours in this area and move toward central Indiana late today into this evening. Deep layer shear is ample, which may allow a few updrafts to at least minimally organize. Timing of arrival is not ideal, and activity should be steadily weakening as it moves into the area, but an isolated severe storm cannot be ruled out entirely before about 9-10 PM in the western portions of the area. Strong wind gusts and perhaps some hail would be the primary threats, but this remains highly conditional. Any precip will continue to spread eastward ahead of the front overnight as the boundary moves into the area. Thunder threat should wane rapidly after dark, ending by midnight. Any lingering rain will come to an end by around daybreak Wednesday as the front exits. Temperatures will remain very warm for the time of year ahead of the boundary, with overnight lows likely to also be near Wednesday`s maximums. Temperatures will steadily drop through the day on Wednesday as cold advection ramps up and have made sure grids reflect this. Wind gusts on Wednesday in the wake of the front can be expected in the 20KT range out of the west/southwest. && .Long Term...(Wednesday night through Tuesday) Issued at 259 PM EST Tue Jan 3 2023 * Seasonable temperatures in the 30s and 40s * Multiple chances for wintry precipitation through the weekend .Thursday and Friday... *Chance for snow showers Thursday* Long term period begins with a deep upper trough in place over the southern Great Lakes with multiple waves rotating around it through Indiana. Strong vort max pivots into the northern half of Indiana Thursday afternoon resulting PVA ahead of it and sufficient lift for precipitation. Forecast soundings show a deep saturated layer around 3-5 km thick through the DGZ with sufficient frontogenetical forcing for snow shower development Thursday afternoon. Guidance tends to perform poorly in these scenarios, therefore deviating from the NBM and adding "scattered PoP" wording to the forecast. Any accumulations would likely be light and since snow showers would be scattered in nature. So do not expect a widespread accumulating snow event..more like nuisance snow showers. Steep low level lapse rates under a cold air advection regime may also allow for gusty winds to 20-25mph to mix down to the surface, especially under any shower activity. So bumped up gusts during the daytime hours Thu and Fri to near NBM 90th percentile to account for higher gust potential. Upper level convergence on the backside of the departing upper low in addition to surface high pressure moving in from the south and west will promote subsidence and drying of the atmosphere into Friday. Despite slowly moderating temperatures aloft, still expecting highs to remain cool in the mid 30s to low 40s with the most sunshine to occur across south and western portions of the state. .Next Weekend Into Early Next Week... *Another chance for wintry precipitation* Towards next weekend, southern branch of the jet stream becomes active with a 130kt jet pushing into the Ohio Valley and stretching southwestward toward Baja California and the Pacific Ocean. Leeside troughing off the Rockies in combination with the left exit region of the upper jet will result in surface cyclogenesis along the Front Range Friday. Guidance shows the low tracking eastward as the exit region of the jet enters the Ohio Valley. Weak high pressure and a somewhat colder airmass remain just to the north of this low. Due to a weaker thermal gradient and the low forming on the right exit region of a relatively zonal jet, not expecting rapid intensification of this low. With a sufficient moisture fetch from the Pacific Ocean and a weak LLJ developing ahead of the low bringing up moisture from the Gulf, expect precipitation to break out across the region Saturday. This set up is typically favorable for a winter precipitation event across the Ohio Valley as a weaker low would keep warmer air to the south and colder air locked in at the surface. Latest forecast soundings do show an interesting set up as colder air remains at the surface Saturday and slightly warmer air moves in aloft. With guidance showing the track of the low right through Kentucky, just south of the area, this could leave to a potential wintry event for Central Indiana. Track of the surface low is key in determining exact impacts from this system. With the surface low being weak, fully expect there to be run to run waffling of the exact track of it. Therefore, confidence remains low on the forecast for Saturday. However, no matter the exact track, a conceptual model of this event leads us to believe a wintry event is possible somewhere in the Ohio Valley and Great Lakes region this weekend. Will be monitoring this closely as the potential is there for mixed precipitation. Looking toward next weekend, broad upper ridging should prevail over interior Canada, blocking cold air intrusions from diving south across the region. Surface high pressure along the eastern side of the upper ridge would likely set-up near the Great Lakes, although guidance is suggesting any such ridging would be rather weak. Longer range guidance keeps high pressure over the Great Lakes region and NE CONUS Sunday through much of next week. Other than the chance for precipitation Saturday, the rest of the weekend and into next week appear dry and cool. && .Aviation...(00Z TAF Issuance) Issued at 637 PM EST Tue Jan 3 2023 Impacts: * Widespread MVFR ceilings this evening. * Showers and a few thunderstorms possible this evening. * MVFR ceilings return tomorrow. Discussion: MVFR ceilings are present across Indiana this evening, and these ceilings should persist into the night. A brief period of low-end MVFR ceilings near 1000ft are possible as a cold front and associated rain showers pass through. A few isolated thunderstorms are possible as well, but with an expected weakening trend of convection currently in Illinois, thunder wasn`t included in the TAFs. Ceilings may lift out of MVFR territory into VFR for a few hours after the front passes by and drier air moves in. Southerly winds will veer and become more west-southwesterly as the front swings through. Speeds will generally remain in the 5-10kt range, with some gusts to 20kt possible after sunrise tomorrow. Behind the front, a cooler air mass with widespread low stratus will move in. Expect ceilings to lower to between 2000 to 2500ft during the day tomorrow. These MVFR ceilings should persist to the end of the TAF period and beyond as an occluded low pressure system passes overhead. && .IND WATCHES/WARNINGS/ADVISORIES...None. && $$ Update...Eckhoff Short Term...Nield Long Term...CM Aviation...Eckhoff
Area Forecast Discussion
National Weather Service Lake Charles LA
853 PM CST Tue Jan 3 2023 ...New UPDATE... .UPDATE... Issued at 851 PM CST Tue Jan 3 2023 A cold front is roughly along a Opelousas to Grand Chenier line and continues to gradually move east. A drier and more stable air mass is filtering in behind the boundary decreasing rain chances. This is in line with the previous forecast and no changes are needed at this time. && .SHORT TERM... (Tonight through Thursday night) Issued at 305 PM CST Tue Jan 3 2023 The storm system continues to take its sweet time moving across the region this afternoon, so the threat for showers/storms continue from roughly Lake Charles to Alexandria east. While the severe threat is steadily dropping, we still cannot rule out a brief strong or severe thunderstorm. Best chance will be across the far eastern third of the CWA. Latest HRRR guidance suggests the frontal system and showers/storms will have exited the entire CWA by 06Z tonight. Once the front moves through, expect gradual clearing. Fog development looks limited tonight and any fog should be patchy at best. The fog would be confined to along the coast from Grand Chenier east and from areas around New Iberia south and east. Wednesday and Thursday are shaping up to be pretty nice days. Temperatures will generally be around 70 degrees give or take, with mostly sunny skies. Thursday will be a little cooler, but highs still in the middle to upper 60s under mostly sunny skies. && .LONG TERM... (Friday through next Monday) Issued at 305 PM CST Tue Jan 3 2023 Warm and dry conditions are expected on Friday as the region remains beneath modest ridging over the southern plains and a surface high centered east of the area. Moisture will increase over the area Friday night into Saturday as the ridge axis aloft translates east in advance of the a weak shortwave crossing the southern Rockies. Surface low pressure over OK will lift northeast, pulling a cold front into the region. Increasing ascent ahead of the system will improve rain chances Saturday, mainly across the western half of the area, with the best chances areawide by Saturday night into Sunday as the front slides into the region. Forecast soundings show modest CAPE, generally below 1000 J/kg, but sufficient for thunder development in some of the convection. Conditions overall look too limited for any organized or severe storms but this will continue to be monitored over the coming days. High pressure building behind the front should help to nudge the boundary offshore by Sunday night, although some overrunning moisture will likely keep clouds and low PoPs over the area until at least Monday. Rain chances should taper off after Monday. However, there is still quite a bit of variability in model solutions toward the end of the long term period, so forecast confidence for the Day 7 and 8 time periods remains low. A warm advection pattern will become established on Friday as southerly winds develop with the surface high to the east. This will allow high temperatures to climb to about 5 to 10 degrees above normal, with maximums in the upper 60s to lower 70s. Temperatures will be even warmer on Saturday with highs into the lower to middle 70s. Temperatures will remain above normal Saturday night, but the passage of the front on Sunday will usher in a slightly cooler airmass and more seasonable temperatures for early next week.&& .AVIATION... (00Z TAFS) Issued at 305 PM CST Tue Jan 3 2023 VFR/MVFR at most TAF sites this afternoon, with the exception of KARA seeing IFR due to low CIGs. KARA should lift out of IFR through the evening. While the threat for showers/storms are lowering by the hour, eastern TAF sites cannot rule out a brief storm/shower. The activity could briefly lower any TAF site down to IFR in heavy rain. The area will clear from west to east with VFR expected at all TAF sites by late evening or in the early morning hours. The signal for FG looks limited, but cannot rule out patchy FG along the coast and over by lower Acadiana. && .AVIATION... (00Z TAFS) Issued at 305 PM CST Tue Jan 3 2023 VFR/MVFR at most TAF sites this afternoon, with the exception of KARA seeing IFR due to low CIGs. KARA should lift out of IFR through the evening. While the threat for showers/storms are lowering by the hour, eastern TAF sites cannot rule out a brief storm/shower. The activity could briefly lower any TAF site down to IFR in heavy rain. The area will clear from west to east with VFR expected at all TAF sites by late evening or in the early morning hours. The signal for FG looks limited, but cannot rule out patchy FG along the coast and over by lower Acadiana. && .MARINE... Issued at 305 PM CST Tue Jan 3 2023 Winds over the waters are diminishing and seas subsiding, thus the Small Craft ADV was allowed to expire at Noon today. There remains a few showers/storms over the waters and this will persist through the rest of the day and perhaps into the evening hours as the frontal system is slow to exit the region. While the storms have been marginal, cannot rule out the occasional Special Marine Warning. && .PRELIMINARY POINT TEMPS/POPS... AEX 51 73 43 66 / 10 0 0 0 LCH 51 71 45 67 / 10 0 0 0 LFT 55 74 47 68 / 40 0 0 0 BPT 50 73 46 69 / 0 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$ SHORT TERM...05 LONG TERM....24 AVIATION...78
Area Forecast Discussion...UPDATED
National Weather Service Baltimore MD/Washington DC
1049 PM EST Tue Jan 3 2023 .SYNOPSIS... A warm front will slowly push northward tonight. A cold front will approach from the west Wednesday before slowly passing through Wednesday night into Thursday. Temperatures remain above normal through Thursday with slightly cooler air following behind the cold front. More seasonable conditions are expected into the weekend. A weak low pressure system may impact the region later in the weekend as well. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Surface warm front remains wedged into the Potomac Valley west of the Blue Ridge and across northeast Maryland this evening, where temperatures remain in the 50s with minor visibility restrictions thanks to saturated low levels. Elsewhere temperatures remain in the mid 60s with a steady south wind. A weak shortwave and jet streak aloft are passing through this evening. Lack of low level forcing and moisture east of the mountains is causing most of the precipitation to evaporate, but a few showers or sprinkles could occur through the early overnight hours. Some guidance indicates fog may form late tonight near the Chesapeake as humid air moves over the cooler waters. Very mild temperatures continue tonight with lows well into the 50s. The current forecast would bring overnight lows to near current daily records. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... Actually think much of the area stays dry on Wednesday morning. Recent trends in guidance really make it hard to have any POPs in the forecast before around noon or so. A gusty southerly flow will pump very warm and moist air into the region Wednesday ahead of the line of showers and storms expected during the afternoon. We could see highs hit the low 70s tomorrow during the early afternoon hours with dew points perhaps in to the low 60s. This could lead to at least some small amounts of CAPE ahead of the line, which could mean a few rumbles of thunder. Do think the severe threat is pretty limited though, as the best forcing comes in well behind the line of showers and storms. However, could see some gusty winds with the showers given the 50-60 knots of available wind shear. Just don`t see it being enough to get severe storms in our area, but can`t rule out some Special Marine Warnings over the waters. Lightning production may be quite limited as any convection would be low-topped in nature. Will maintain a slight chance for thunderstorms through late in the evening as the cold front does not arrive until the overnight hours. High-resolution models continue to vary in their depictions of the event. Several models keep us dry, while the 12z NAMNest brings a broken line of storms through the whole CWA. Meanwhile, the HRRR keeps activity south of DC, where instability is likely to be the highest. With decreasing temperatures aloft with the cold front, some drop off in temperatures are expected at night and into Thursday. Westerly flow in the column will offset some of the cold advection given a downsloping regime. Forecast soundings show decent mixing in the lowest 100-150 mb. Based on 850-mb temperatures around 0C, this would favor high temperatures in the mid 50s to low 60s. A few showers are possible early on near the Chesapeake Bay. With the front racing ahead of the main upper trough. Some rain/snow mix is possible along the Allegheny Front on Thursday night which may cause light accumulations on untreated surfaces. Overnight lows fall into the 30s to low 40s with mid/upper 20s along the Alleghenies. && .LONG TERM /FRIDAY THROUGH TUESDAY/... On Friday, surface low pressure will be located to the northeast as high pressure builds into the area behind an exiting cold front. Lingering moisture wrapping around the low in New England may bring precipitation to Alleghenies. Given the expected temperatures in the low 30s, upslope light snow may be possible Friday morning, as well as Saturday morning. Guidance is in good agreement showing a shortwave trough moving eastward out of the Plains on Saturday, but details regarding this feature are less certain. The GFS and ECMWF are in good agreement bringing a surface low eastward toward the region with associated precipitation moving into the area late Saturday into Sunday. The Canadian is slower with the feature, not impacting the area until late Sunday into Monday, and takes it more north. As of now, most of the precipitation, is expected along and west of the Blue Ridge, though some light showers may spread east. Any wintry precipitation should also be restricted to along and west of the Blue Ridge. Temperatures will still be slightly above normal through the period, with high temperatures hovering in the 30s to 40s, and lows in the the 20s to 30s. && .AVIATION /04Z WEDNESDAY THROUGH SUNDAY/... Warm front remains near MRB and MTN this evening but should inch to the north tonight. That would allow MVFR vsby at MRB to improve, but confidence isn`t too high given the current persistence. Areas of MVFR ceilings also moved across CHO, but current thinking is primarily VFR should occur overnight behind a departing disturbance. Southerly winds could gust up to 20 to 25 knots at times through the evening. Some guidance indicates fog may develop near the Chesapeake toward dawn as humid air moves over cooler waters. For now have introduced a period of MVFR at BWI/MTN. On Wednesday, some showers will impact the region which may lead to some restrictions at the terminals. A non-zero thunderstorm threat exists as well, especially for the southern TAF sites like KCHO. Gusty, low-topped showers are possible through Wednesday night as the cold front treks through. Otherwise, most guidance does indicate MVFR to IFR ceilings through a large portion of the day. Can`t rule out LIFR if we end up in a more stable/stratiform rain event. Winds quickly shift to northwesterly by Wednesday evening in the wake of this frontal passage. Shower chances are pretty low as much drier air begins to move into the region. VFR conditions are expected Friday and Saturday. Winds out of the W/NW will likely be gusty with an exiting upper trough, with gusts around 15-20 kt. Winds should diminish Friday night. Some precipitation may approach western terminals Saturday evening. && .MARINE... Southerly winds are resulting in SCA conditions across much of the waters this evening. These winds should gradually diminish overnight as low level stability develops. A few gusts near criteria may continue into Wednesday, but confidence is not high enough to extend the advisory. By Wednesday evening, SCAs may be needed once again, although there doesn`t appear to be an exceptionally strong push of winds with a relatively weak cold front. Additionally Wednesday afternoon, some gusty low-topped showers are possible ahead of a cold front. A Special Marine Warning or two is not out of the question for portions of the waters, especially over the lower Potomac and Bay zones. Winds shift to northwesterly on Thursday with gusts quickly falling below SCA criteria. Winds out of the W/NW may approach SCA criteria for portions of the waters Friday afternoon. Winds should diminish overnight with sub- SCA conditions expected on Saturday. && .TIDES/COASTAL FLOODING... Tidal levels have been rising today ahead of an approaching cold front. Anomalies are expected to further rise through before the cold front tracks through on Wednesday evening. A few locations are forecast to hit Action stage. && .CLIMATE... The following record high temperatures were set today (Jan 3): DCA: 69 (68, 2004/2000) IAD: 69 (68, 2000) BWI: 69 (68, 2000) Continued warmth through Wednesday may lead to some daily records across the region, both for high temperatures and warm overnight lows. *Wednesday January High Temperature* DCA: 73 (1997) IAD: 74 (1997) BWI: 70 (2000) MRB: 75 (1997) *Wednesday January 4 High Minimum Temperature* DCA: 60 (1950) IAD: 51 (1997) BWI: 61 (1950) MRB: 54 (1997) && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory until midnight EST tonight for ANZ530-531- 535-536-538-539. Small Craft Advisory until 6 AM EST Wednesday for ANZ532>534- 537-540>543. && $$ SYNOPSIS...CJL NEAR TERM...ADS/CJL SHORT TERM...CJL LONG TERM...CAS AVIATION...ADS/CJL/CAS MARINE...ADS/CJL/CAS TIDES/COASTAL FLOODING...LWX CLIMATE...LWX
Area Forecast Discussion
National Weather Service Morristown TN
933 PM EST Tue Jan 3 2023 ...New UPDATE... .UPDATE... Issued at 918 PM EST Tue Jan 3 2023 We`re in a lull between rounds of showers and thunderstorms tonight into early Wednesday morning. High resolution CAMs are coming into better agreement that a second round of strong convection will move into southeast Tennessee during the overnight hours. Sounding profiles would suggest another round of a mainly wind threat with overnight/early morning storms. However as the shortwave from the plains begins to approach we could see an uptick in lower level shear. Dew points in the 60`s are starting to move into northeast AL and parts of southern TN indicating that the atmosphere is destabilizing ahead of this next round of convection. Still think the primary threat will be strong winds up to around 60mph, but cannot rule out an isolated tornado either. Highest risk area is southeast TN counties along the AL/GA border. Secondarily, will extend parts of the wind advisory for the far southern Appalachian Mountains into the early afternoon on Wednesday. Previously we had hoped there would be a lull in observed wind speeds in the mountaintops ahead of the second LLJ strengthening over northern GA overnight... However there are still observations in the Smoky mountains recording wind speeds around 50mph. Lower confidence on hitting advisory criteria winds overnight into tomorrow as the jet looks to be displaced a bit far to our south, but enough of the high resolution models are showing 10m winds gusts over 40 knots that an advisory is warranted. && .SHORT TERM... (This evening through Wednesday) Issued at 221 PM EST Tue Jan 3 2023 Key Messages: 1. Showers and thunderstorms, possibly severe, will affect the area through the rest of this afternoon. 2. A second round of showers and thunderstorms is expected Wednesday morning, with the potential for severe storms in SE TN and SW NC. 3. Strong winds continue this evening in the mountains of East Tennessee. The threat of severe thunderstorms with a QLCS will continue for the next few hours, with the area of highest threat of damaging wind gusts being in the southern TN Valley and SW NC counties. Although the Tornado Watch is south of our area, a quick spin-up along the line cannot be ruled out. Behind this line, we should have a lull in precip as the atmosphere will be stabilized. However, a second round of showers and thunderstorms is expected late tonight and Wednesday morning in association with the surface frontal passage. Frontogenesis strengthens as the front moves into Middle TN/AL, which draws moist and unstable surface air northward. The northward extent of this instability, and the pattern of convective development across GA, will determine the severe potential on our area. The HRRR had been the most bullish model with the northward surge of instability with previous runs, but has trended southward with the most recent runs. Other CAMs, such as the FV3 and ARW, develop more convection in GA with a SW-NE orientation, keeping surface- based instability well to our south. The NAM and RAP bring SBCAPE values of 400-700 J/kg just across the GA border between 11-14Z, with 0-1 km shear values of 30-35 kt. Overall, confidence is low that the severe threat will reach our area, but if it does, our southern tier of counties (Hamilton to Clay NC) could have a threat of damaging winds and tornadoes in the early morning hours. For most of the area outside the southern-most counties, convection Wednesday morning will remain elevated, with a lesser potential for strong/severe storms. However, these will be efficient rain-producers, with strong upper divergence acting on anomalously high PW values of 1.3-1.5 inches. If storms repeatedly track over the same areas, flooding will be a threat. QG forcing should exit the area between 15-18Z, and dry air will build in behind the exiting front through the afternoon. With the main upper trough axis still to our west, decreasing clouds, and a SW flow through the column, we will remain rather mild on Wednesday afternoon, with temps in the 60s. The Wind Advisory will be extended until 10 pm this evening based on obs showing winds continuing to gust between 30-50 mph in the mountains and foothills. After that time, the models show the LLJ quickly diminishing. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 221 PM EST Tue Jan 3 2023 A quieter weather pattern is expected for this period, with temperatures generally close to normal values for early January. A closed low will be tracking east across the Great Lakes to New England through Thursday into Friday. As the mid/upper level trough axis crosses our area, we will have cold advection and some steepening lapse rates in northern portions of the area. This could result in some sprinkles/flurries in SW VA and the mountains Thursday night/Friday morning. Moisture appears too limited at this time to expect any accumulation. A weak ridge builds over the area on Friday, which should provide a dry period through Friday night. Rain chances return on Saturday as a trough moves across the Plains, and a brief window of moisture advection from the Gulf opens up ahead of this system. With models disagreeing on the evolution and timing of this system, will have just a low to slight chance PoP Saturday and Sunday. The models continue to diverge regarding a potential system in the Monday/Tuesday time frame. Will carry a slight chance PoP for these periods, as shown by the NBM. && .AVIATION... (00Z TAFS) Issued at 626 PM EST Tue Jan 3 2023 Rain remains near the KTRI terminal, but should clear out in the next few hours. Expect most of the overnight hours to remain calm, before another round of storms in the morning. Some uncertainty on when the front edge will move in. Have gone with TEMPO VCTS during the period when strongest storms are expected. Once the storms move out expect VFR conditions to slowly return during the daytime. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 62 69 43 57 / 80 70 0 0 Knoxville McGhee Tyson Airport, TN 60 68 41 54 / 70 80 0 0 Oak Ridge, TN 60 67 40 54 / 60 70 0 0 Tri Cities Airport, TN 57 66 40 53 / 80 80 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...Wind Advisory until 1 PM EST Wednesday for Blount Smoky Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains- Southeast Monroe. VA...NONE. && $$ SHORT TERM... LONG TERM....DGS AVIATION...
...Updated Aviation Forecast Discussion...

.DISCUSSION... Issued at 300 PM CST Tue Jan 3 2023 Key Messages: - Light snow north of I-80 corridor gradually ending this evening south to north. - Dry conditions heading into and through this weekend. Water vapor imagery this afternoon clearly showing upper low pressure centered over eastern NE slowly lifting toward the upper Midwest. Meanwhile, regional 88D was showing bursts of light/moderate snowfall along/north of I-80 within area of upglide/steep mid layer lapse rates on the backside of the system. Per the RAP it appears that adequate omega the rest of this afternoon and evening via vort lobes rotating down the backside of the system/pockets of isentropic upglide to support areas of light snow over the northern CWA. This may equate to an additional inch of snow by midnight. Current headlines for advisory expire at 6pm. At this point, do not believe conditions will be significant enough to warrant extending the advisory into the evening hours. Late tonight into Wednesday, soundings suggesting patchy freezing drizzle possible over portions of northeast NE as well as west-central IA. Otherwise, it appears per medium range models that a dry forecast is best fit for the CWA heading into and through next weekend. However, have noted that models push a system through KS on Saturday and generate QPF from eastern KS into MO. Will be interesting to see if models end up shifting its track a bit father north. But again, feel comfortable enough to go dry all the way through early next week. Highs: Wed - mid 20s/mid 30s Thu - mid 20/mid 30s Fri - low 30s/low 40s Sat - low 20s/low 30s Sun - upper 20s/mid 30s Mon - low 30s/low 40s Tue - low 30s/low 40s && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 521 PM CST Tue Jan 3 2023 Lingering light snow will continue to taper off over the next couple of hours across northeast Nebraska. Another light burst of snow could develop over the KOFK area around 12Z Wednesday morning, otherwise, dry conditions will prevail. VFR conditions should spread back into KLNK by 18Z Wednesday. MVFR ceilings will remain over KOMA and KOFK through the period. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Winter Weather Advisory until 6 PM CST this evening for NEZ011- 012-015>018-030>034-042>045-050>053-065-066-078. IA...Winter Weather Advisory until 6 PM CST this evening for IAZ043- 055-056-069. && $$ DISCUSSION...DEE AVIATION...KG
Area Forecast Discussion
National Weather Service Nashville TN
805 PM CST Tue Jan 3 2023 ...New UPDATE... .UPDATE... Issued at 753 PM CST Tue Jan 3 2023 The lull before the cold front is currently happening. The HRRR has the next wave of showers and thunderstorms coming up from the south after 05Z. This still looks like the eastern 2/3 of the forecast area /I-65 and east/ will be the area of focus. The good news is the showers move off the plateau by 15Z with the threat for severe weather ending around 6 am. The main threat damaging winds and hail...with a tornado or two possible. && .SHORT TERM... (This afternoon through Thursday Night) Issued at 159 PM CST Tue Jan 3 2023 The second of three rounds of potential severe weather has now exited the cwa, The tornado watch has been cancelled for those last remaining eastern counties. Conditions have stabilized across the mid state, but we are looking at the main frontal boundary upstream. Thus, that 3rd round of potentially severe weather is upcoming this evening and overnight. SPC still holds a slight risk for the southeastern two thirds of the mid state through 12Z. The light rain that covers eastern areas of the mid state will continue to decrease from west to east. This activity will exit our Plateau around 5p to 6p or so. then, we will begin to see some destabilization once again as the aforementioned cold front heads our way. The good news is that it appears that the forcing along and ahead of the boundary looks a touch weaker. Furthermore, 850 mb energy and helicities look weaker as well. Nonetheless, showers and tstms will increase once again just after 00Z and spread eastward overnight. Additional qpf does not appear to pose any flood threats. The system will continue to be a slow mover, with the residual shower activity finally exiting our Plateau just after 12Z. Moving on, some sunshine will return on Wednesday, with even more on Thursday. The replacement airmass looks rather mild still with lows expected to be in the 30s and highs in the 50s. && .LONG TERM... (Friday through next Tuesday) Issued at 159 PM CST Tue Jan 3 2023 In the extended forecast, looking nice into Friday. Then the southern branch of the jet stream will become active. A frontal boundary will bring some showers to the area over the weekend. This feature may stall to our south with some energy forming along the boundary. Moisture will spread back northward into early next week. Precip amounts look light and the airmass to our north does not look all that cold. Thus, just looks like low chances for rainfall for now. There is quite a bit of uncertainty with the timing of any precip during the period. So with the light amounts expected, will just include low pops for a lengthy duration. For the extended temps, values will run about 5 to 10 degrees above normal. && .AVIATION... (00Z TAFS) Issued at 629 PM CST Tue Jan 3 2023 VFR conditions are expected at BNA/MQY/CKV this evening before another round of SHRA/TSRA brings MVFR conditions between 05-09Z. Conditions will improve back to VFR thereafter. At CSV, MVFR/IFR conditions are expected this evening and overnight as TSRA spread back over the airport from 06-12Z, followed by a return to VFR on Wednesday morning. South winds this evening will veer to southwest overnight then westerly on Wednesday morning, with gusts to 20 knots during the day on Wednesday. && .PRELIMINARY POINT TEMPS/POPS... Nashville 57 61 38 53 / 90 10 0 0 Clarksville 52 57 35 51 / 50 0 0 0 Crossville 57 63 36 50 / 90 70 0 0 Columbia 56 61 37 53 / 90 10 0 0 Cookeville 59 63 37 51 / 90 60 0 0 Jamestown 57 63 36 49 / 90 70 0 0 Lawrenceburg 58 62 37 54 / 90 20 0 0 Murfreesboro 58 63 37 53 / 90 30 0 0 Waverly 52 56 35 51 / 60 0 0 0 && .OHX WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE.......12 SHORT TERM...21 LONG TERM....21 AVIATION.....Shamburger
Area Forecast Discussion
National Weather Service Raleigh NC
825 PM EST Tue Jan 3 2023 .SYNOPSIS... Mild, moist southwesterly flow will increase ahead of a cold front approaching from the west through tonight. The cold front will move into the area late Wednesday and Wednesday night. Cooler high pressure will follow Thursday into the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 825 PM Tuesday... Radar indicated a continued weakening line of showers (mostly light, with a few isolated heavier bursts of rain) pushing quickly to the ESE across the Piedmont. Some light rain or sprinkles continue after the initial line passes over northwest and west-central NC. Rainfall amounts have been less than 0.10 for the most part with this line. The HRRR seems to have a fairly good handle on the current convective trends. This initial line should continue to weaken as it moves east toward FAY and RDU. The lack of any instability will keep any additional activity weak overnight. Expect some showers to be focused over the southern Piedmont and Sandhills for a few hours between late evening and the early morning hours. The thunderstorms over GA will gradually move ESE toward the more unstable air over central and southern SC (stay to the south of our southern counties overnight. Additional storms will form along the cold front over the TN Valley later tonight - and with additional showers and isolated storms not expected for our region until Wednesday. Temperatures: Temperatures were in the lower to mid 60s at mid- evening. Lows in the upper 50s to lower 60s are still expected. The forecast lows would tie or break record high minimums at all three climate sites. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... As of 252 PM Tuesday... Aloft, the low will meander over the upper MS Valley through Wed night as the attendant trough and embedded shortwaves migrate eastward. Gulf and Pacific moisture will increase Wed/Wed night, with the moist axis moving through central NC Wed eve/night. The moist axis extending north-northeastward through the Southeast and mid-Atlantic should shift off the East Coast by Thu. At the surface, a warm front will lift northward through the area late Tue night/Wed ahead of the approaching cold front. While the parent low sits over the upper MS Valley on Wed, a secondary low will break off and progress eastward through the OH Valley and into the northern mid- Atlantic/Northeast Wed/Wed night. Meanwhile, the attendant cold front will progress east of the Appalachians Wed night and move through central NC thereafter, though timing is uncertain. The best chance for heavy rain and thunder will be ahead of the front Wed/Wed night. The timing of the cold front continues to vary between the medium-range guidance, with fropa timing sometime between late Wed night and Thu eve. Temperatures: Although forecast uncertainty remains, there is high confidence temperatures will be significantly above average and wide ranging across central NC. Expect highs in the mid 60s NW to upper 70s SE across the Coastal Plain. Lows will ultimately depend on fropa timing, but for now expect mid 40s NW to mid/upper 50s SE. Rain and Storms: Instability still appears to be somewhat limited, generally 500 J/Kg or less, while shear and helicity are still more robust. There is at least a slight chance for thunder across all of central NC Wed aft/eve. The SPC has all of central NC in a marginal risk for severe weather on Wed with the primary threat of isolated strong to severe storms capable of damaging wind gusts. Rainfall totals should generally range from half an inch to an inch, though some locally higher amounts are possible. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 219 PM Tuesday... The main moisture axis should be well offshore by 12Z Thursday promoting dry conditions locally as the upper trough lifts into the northeast. The sfc cold front will slowly move across central NC during the day on Thursday, clearing cloud cover from west to east through Thursday night. CAA will lag behind the cold front, allowing daytime highs on Thursday to still reach well above normal into the mid to upper 60s. Overnight lows will dip down into the mid to upper 30s. Flow aloft turns more nearly Friday through Saturday as weak upper ridging builds across the southeastern US. At the surface, high pressure from the deep south will ride northeastward along the southern Appalachians Friday through Saturday promoting dry conditions across our area. Daytime highs in this period will be a bit chillier compared to this past week, reaching the mid to upper 50s (near-normal). Calm to light winds coupled with relatively clear skies Friday night could promote good radiational cooling potential. Thus, lows are forecast to drop into the upper 20s to lower 30s Friday night. Increasing clouds Saturday night should negate decoupling potential, with a bit warmer lows in the upper 30s to lower 40s expected across our area. A upper level shortwave is expected to dig into the central Appalachians region Sunday into Monday. Ensemble guidance is in pretty good agreement to track a sfc low well north of our area, but an associated cold front will likely push through Sunday into Monday. Generally wnwrly flow aloft is expected in this time period which should keep things relatively dry (the latest GFS has come more into agreement with the Euro in depicting more zonal flow aloft and dry conditions Sunday into Monday). However, models are still a bit split on light rain potential later on Monday through Tuesday. The GFS develops a second sfc low along the departing cold front producing light rain late Monday into Tuesday. Conversely, majority of the most recent Euro runs have kept this period dry (although the latest 12Z run does produce some precip in this period). Ensemble wise, median output from the GEFS and EPS are currently depicting very low probabilities of rainfall for this time period (the CMC is a bit more enthused, but still only pumps out a few hundreds of an inch). Given the trends in the ensemble data, decided to keep the forecast dry at this point for Sunday through Tuesday, but will be worth re-evaluating as we get closer. Daytime highs should remain near normal from Sunday through Tuesday mostly in the mid to upper 50s (perhaps a touch warmer on Sunday; a touch cooler on Monday). Overnight lows will dip into the mid 30s over this period as well. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... As of 645 PM Tuesday... Predominantly VFR conditions are observed across central NC with the exception of the Triad (GSO/INT) on the edge of a band of low MVFR ceilings. CIGS are expected to lower into the IFR/LIFR categories between 08z and 11z tonight and remain Wednesday morning. SW surface winds should remain between 5-10kts overnight beneath a strong low- level jet that will be located around 2-3k feet at 30-40kt. However, pilots should be advised that strong winds will persist at 2kft over all terminals through the TAF period, even strengthening to 40-50kts out of the southwest Wednesday afternoon. A line of showers and possibly isolated thunderstorms will move through ahead of a cold front near the end of the TAF period with the latest timing for terminals as follows: 16-20z at GSO/INT, 19-22z RDU, 20- 23z FAY/RWI. Looking beyond 00z Wednesday, MVFR/IFR cigs and vsby will be possible, especially in the east, Wednesday night into Thursday morning. VFR conditions return by Thursday. && .CLIMATE... Record Temperatures for Wednesday January 4: SITE RECORD MAX RECORD HIGH MINIMUM GSO 74/2005 57/1950 RDU 76/2005 58/1950 FAY 77/2004 60/2004 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett/KC NEAR TERM...Badgett/KC SHORT TERM...KC LONG TERM...Luchetti AVIATION...Badgett/Swiggett CLIMATE...RAH
Area Forecast Discussion
National Weather Service Sacramento CA
317 PM PST Tue Jan 3 2023 .SYNOPSIS... A weak weather system will continue to bring light rain and mountain snow tonight. A serices of stronger storms will move through Wednesday into next week. Strongest storms are expected Wednesday through Thursday and again over the weekend. Widespread damainging winds are expected Wednesday afternoon into Thursday. Heavy precipitation will keep flooding threats elevated and mountain travel impacts at the forefront for the rest of the week into the weekend. && .Discussion... A weak shortwave moving through today and tonight will continue to bring light precipitation with little to no impacts. A much stronger storm will spread into the region bringing strong, damaging winds with heavy rain and mountain snow Wednesday through Thursday. This is hybrid storm, with a deep Pacific low off the coast tapping into a very moist Atmospheric River(AR). The combination of strong dynamic lift and abundant moisture will bring moderate to heavy rain and heavy mountain snow, especially Wedensday evening into early Thursday. Elevated flood and recent burn scar concerns are expected, as well as major mountain travel impacts in periods of heavy snow are expected. A strong surface pressure gradient coupled with a strong low level wind jet (65 kt at 925mb) will bring increasing southerly winds through the day Wednesday, peaking Wednesday night. Sustained winds 25 to 35 mph with gusts up to 50 to 60 mph are expected in the Valley and foothills, so the High Wind Watch has been upgraded to a Warning from 10 AM PST Wednesday to 4 pm PST Thursday. These strong winds coupled with saturated ground will likely bring down trees and cause the potential for widespread power outages. This will also cause difficult travel for high profile vehicles such as trucks and RVs. The wind is expected to diminish Thursday evening. Precipitation will spread into the area with a warm front early Wednesday. Snow levels will initially be low early Wednesday, around 4,000 feet, then rapidly with warmer air advecting in to around 7,000 feet Wednesday night. Snow levels will drop to around 5,550 feet early Thursday behind a cold front. The majority of the snow is expected above 5,000 feet, but snow levels associated with AR`s can be tricky, resulting in either higher or lower snow levels at times. If driving along roadways between 4000-6000 feet, be prepared for both heavy rain and/or heavy snowfall. Mountain travel impacts are likely, with 1 to 3 feet of mountain snow, locally hight over peaks. Snow may fall at rates up to 3 inches an hour, bringing very slippry conditions and whiteout conditions, when combined with winds gusting to 60 to 70 mph. The winds could also bring down trees, potentially blocking roads and causing power outages. The Winter Storm Warning continues for elevations above 5,000 feet from 7 am PST Wednesday through 4 AM PST Friday. The wet moisture tap from the AR will bring moderate to heavy rain for elevations below 5,000 feet. Uplsope flow will be less of a factor than the previos system, with rainfall amounts 1.50 to 3.00 inches in the Valley, with 3 to 7 inches in the foothills and mountains. Rainfall will bring river rises, as well as renewed flooding threats, mainly to small streams and creeks and to low lying areas. This is due to streams already being elevated by the previous storm, as well as saturated ground. A Flood Watch continues for the Valley, Delta and foothills from Wednesday morning through Friday morning. The HREF and HRRR show heaviest rainfall is expected to be Wednesday evening into early Thursday. Narrow Cold-Frontal Rainbands have been porjected by the HRRR, which could bring locally heavy rainfall. These could impact recently burned areas. Confidence this far our in rain rates exceeded debris flows is currently low, but due to the potential extreme impact a Flash Flood Watch has been issued during the expected time period of heaviest rainfall, from Wednesday afternoon to Thursday evening. Lingering showers are expected on Friday, as the storm exits and weak mesoscale ridging develops. This will be a brief lull before the next system spreads in Friday night. && .EXTENDED DISCUSSION (Saturday THROUGH Tuesday)... Wet weather continues through the extended forecast period as models indicate additional Pacific storms moving through but differ with timing and QPF. CW3E AR Landfall tool points to multiple ARs with the strongest Sunday into Monday. There is the p otential for significant flooding issues as snow levels rise through the extended period and run-off intensifies on already saturated soils and elevated rivers and streams. While exact details remain uncertain, early projected rainfall amounts are around 2 to 4 inches in the Valley. High elevation snow totals could be heavy and measure up to a few feet. && .AVIATION... MVFR/VFR conditions are forecast with localized IFR/LIFR ceilings over the next 24 hours. Surface winds today generally at/below 15 kt. Southerly winds increase at the tail end of the TAF period with possible low level wind shear in the Sacramento area terminals and points south. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 7 AM Wednesday to 4 AM PST Friday for Mountains Southwestern Shasta County to Western Colusa County- Shasta Lake Area / Northern Shasta County-West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. Flash Flood Watch from Wednesday afternoon through Thursday morning for Burney Basin / Eastern Shasta County-Motherlode- Mountains Southwestern Shasta County to Western Colusa County- West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. Flood Watch from late tonight through Friday morning for Carquinez Strait and Delta-Central Sacramento Valley-Motherlode- Mountains Southwestern Shasta County to Western Colusa County- Northeast Foothills/Sacramento Valley-Northern Sacramento Valley- Northern San Joaquin Valley-Southern Sacramento Valley. High Wind Warning from 10 AM Wednesday to 4 PM PST Thursday for Carquinez Strait and Delta-Central Sacramento Valley-Motherlode- Mountains Southwestern Shasta County to Western Colusa County- Northeast Foothills/Sacramento Valley-Northern Sacramento Valley- Northern San Joaquin Valley-Southern Sacramento Valley. && $$
Area Forecast Discussion
National Weather Service Topeka KS
425 PM CST Tue Jan 3 2023 ...AVIATION UPDATE... .DISCUSSION... Issued at 243 PM CST Tue Jan 3 2023 Forecast Key Points: - Near normal temperatures through Thursday, the above normal Friday and early next week. The mid level low was located near the Nebraska and Iowa line moving northeast this afternoon. Areas of clouds rotating around the low continued across much of Kansas northward into Nebraska and Iowa. Latest surface analysis had a surface low in western Iowa with westerly winds on the backside across northern Kansas. Temperatures have remained nearly steady or have fallen through the day. Expect the clouds to gradually decrease tonight from southwest to northeast as the mid level low moves off to the northeast. Lows tonight will drop into the low to mid 20s. Some clouds may linger or redevelop in the northeast on Wednesday, keeping highs in the 30s there while highs in the 40s are expected elsewhere. A northwest flow regime will transition to weak ridging over the central Plains on Friday as a trough moves across the west. Friday looks to be the warmest day this week with highs in the mid 40s to lower 50s. The western trough will moves across the Plains with a surface low moving across Friday night and Saturday. This will bear watching as some light precipitation will be possible with this system. Cool advection on the backside of the departing system on Saturday will keep highs in the 30s to lower 40s for the weekend. Temperatures warm back up for the start of next week as heights rise in advance of the next trough approaching the Plains. && .AVIATION...(For the 00Z TAFS through 00Z Thursday) Issued at 425 PM CST Tue Jan 3 2023 With the low pressure system still over western IA and models showing it slow to move east, think the MVFR CIGS are going to be hard to get rid of. The 18Z guidance is trending this way as well keeping the CIGS until mid morning Wednesday. Bases may fluctuate around 3 KFT but for the most part think CIGS will prevail between 2500 and 3000 feet. The RAP wants to hold onto the MVFR CIGS well into Wednesday. But forecast soundings show the cloud layer thinning with decent mixing. So will go with the NAM and GFS that scatter out the low clouds by the late morning hours. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION...53 AVIATION...Wolters