####018007927#### FXUS61 KGYX 241817 AFDGYX Area Forecast Discussion National Weather Service Gray ME 217 PM EDT Wed Apr 24 2024 .SYNOPSIS... Low pressure moves into the region today bringing rain showers and perhaps a few snow flakes to the mountains. Dry high pressure then moves across the region Thursday through Saturday. A warming trend can be expected over the weekend with chance of showers Saturday night or Sunday. Warmer weather is then expected early next week. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... 2pm Update...Quick update to refresh current PoPs and expectations for the afternoon. Primary area of showers is now pulling into eastern Maine. Behind, nearly full sun has popped out across southern NH and interior to coastal ME. This has caused a quick spike in temperatures into the mid to upper 50s, with a couple 60 degree readings sprinkled in mainly in southern NH. With this good surface heating and incoming cold front, expect some convective showers to develop which are now entering from western NH. Upstream obs have been pretty gusty, with a number supporting 30 to 35 mph gusts at times. These could linger into the evening hours considering the cooler air aloft moving in. Again can't dismiss a few rumbles of thunder in southern NH or far southern ME, along with any deeper showers potentially containing graupel. 1030am Update...Near term forecast looks okay this morning. As new data comes in, made some changes to afternoon, mainly for winds and afternoon shower coverage. Faint fineline in MRMS comp radar through Montreal this morning is bringing gusts to 35 mph. This is set to make its way south through the area along with passing cold front this afternoon. Upped wind gusts for a few hours this afternoon to align with this front passing. Looking at HREF probabilistic momentum transfer, gusts 25 to 35mph look most likely, but can't rule out some gusts around 40 before the sun sets. There will also be a brief window of instability ahead of the front that, once prompted by lifting, could develop deeper showers and possibility of a couple rumbles of thunder later in southern NH. CAPE values are slim, not much more than 200 j/kg, so will be conditional on any further surface heating through early afternoon. 630am Update... Have upped the pops this morning as some areas were reporting very light rain as of 10Z despite plenty of dry air initially in the latest soundings. Showers will continue through at least early this afternoon before drier and colder air arrives later in the day. Minor adjustments to temperatures, dew points and winds for the near term portion of the forecast. Prev Disc... A cold front will cross the region today with an upper level short wave crossing the region during the midday hours. Models continue to be in relatively good agreement developing a weak area of low pressure along this system. Showers will cross western Maine and New Hampshire with the highest pops over the northern mountains. The precipitation may end as a brief period of snow across the higher terrain this afternoon. Little accumulation is expected. Strong cold air advection and an increasing gradient will allow for gusty winds towards the later portion of today. Afternoon highs will generally be in the 40s north to the 50s in the south. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Gusty winds expected tonight with GYX probabilistic data plots suggesting wind gusts in excess of 25 kts. Clearing will continue as a large ridge of high pressure builds into the region from Canada. It will be chilly with lows in the upper teens north to the 20s south. Much less in the way of wind is expected for Thursday as the ridge builds over northern New England. Highs will once again reach the 40s in the north to the lower to mid 50s across the south under mostly sunny conditions. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... Overview: A large dome of high pressure builds over the eastern CONUS Thursday through Saturday. This will result in warm days and cool nights under partly to mostly sunny skies. High pressure then moves to our east by early Sunday as a weak frontal boundary arrives from the west, resulting in an increased chance for scattered showers Saturday night through part of Sunday. Showery conditions at times along with warm temperatures look to continue through early to mid next week. Impacts: Low afternoon RH is likely on Friday with values falling into the teens to 20s percent range. This will be in combination with west-northwesterly wind gusts up to around 25 mph, which could result in increased fire weather conditions. Forecast Details: Surface high pressure will build over the eastern CONUS on Thursday through Saturday, resulting in warm days and cool nights. Thursday night will feature mainly clear skies along with light winds, which will result in good radiational cooling conditions. Therefore blended in raw MOS guidance into the overnight forecast, which brings some interior valleys down into the teens to near 20 degrees with middle 20s to near 30 degrees elsewhere. Friday will feature partly to mostly sunny skies with warm afternoon temperatures into the 50s to middle 60s from north to south. Westerly winds up to around 20-25 mph combined with afternoon RH into the teens to 20s percent range could result in increased fire weather concerns but it will otherwise be a nice day. Another night of radiational cooling is then likely Friday night under mostly clear skies and light winds. Lows will range from the 20s to lower 30s. Light winds and warm temperatures will prevail on Saturday with highs into the 60s in most locations. The weak flow will likely result in a sea breeze though, which would keep the coast cooler given current SSTs. Clouds will increase by Saturday night with perhaps a few scattered showers by dawn as a front approaches from the west. Scattered showers and mainly cloudy skies are then likely on Sunday as the frontal boundary remains near the region. It does not look like a washout though and latest ensemble guidance suggests light rainfall amounts. Despite the clouds it will remain warm with perhaps a few 70 degree readings over southern NH depending on cloud cover. Depending on the placement of another frontal boundary, some showery weather will remain possible at times through the first half of next week but rainfall looks to remain on the light side with temperatures remaining mild. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... Short Term...Conditions lowering to MVFR today in showers with areas of IFR possible in the precipitation and lowered ceilings. Conditions improve tonight to VFR and continue on Thursday however some MVFR conditions may linger in the mountains. Long Term...VFR prevails Thursday night through Saturday with high pressure overhead. Scattered -SHRA arrives Saturday night through part of Sunday with possible lower ceilings. && .MARINE... Short Term...SCAs have been issued as winds will be increasing over the coastal waters beginning this afternoon. A few gusts may approach gales for a short period this evening. Long Term...Winds and seas to remain below thresholds hazardous to small crafts as high pressure builds over the waters. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 8 AM EDT Thursday for ANZ150-152- 154. Small Craft Advisory from 6 PM this evening to 4 AM EDT Thursday for ANZ151-153. && $$ NEAR TERM...Cornwell SHORT TERM...Cornwell LONG TERM...Ekster ####018004390#### FXUS62 KCAE 241819 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 219 PM EDT Wed Apr 24 2024 .SYNOPSIS... A front will move into the area this evening with isolated showers possible. Fair Thursday and Friday, except for a slight chance of a shower over western areas Friday afternoon. Fair Saturday through Monday with a warming trend. A cold front is expected to bring a slight chance of showers and thunderstorms Tuesday. && .NEAR TERM /THROUGH TONIGHT/... A backdoor front will move into the western/northern Midlands today then push through the eastern Midlands and southern CSRA around midnight. Unlike the previous backdoor front this past weekend, dry air and cooler temps aloft will hinder convective development and limit the threat of any thunderstorms/severe weather. muCAPE values are likely to be less than 250 J/kg making thunderstorms unlikely. Any rainfall amounts would be light given the relatively low atmospheric moisture content with GOES-16 derived PWATs only around 1 inch. The front will move offshore during the early morning hours with skies beginning to clear behind the front and winds turning northerly. This will bring a bit cooler and drier air to the area with overnight lows ranging from the around 50 degrees in the western Midlands to the mid 50s in the eastern Midlands and CSRA. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Thursday and Thursday night: Upper trough continues to slowly slide away from the region as upper ridging begins to build overnight. At the surface, high pressure begins to wedge in from the north, pushing a frontal boundary to the south and west. Latest guidance continues to indicate that this boundary remains too far away from the area to spark any shower activity, keeping the area dry. Afternoon highs are forecast to be similar to slightly lower than today as northwest flow aloft will aid in some downsloping. Overnight temps remain on the mild side as well. Friday and Friday night: Upper ridging is expected to continue building over the region on Friday. However, a weak shortwave embedded within the ridge is forecast to move through the area. Additionally, weak surface convergence is possible as the frontal boundary wavers through the day. More models are picking up on the chance for rainfall during the afternoon due to these features. With the weak shortwave and surface convergence, only expecting isolated showers to develop and have expanded a slight chance (~20%) of showers from the CSRA to the central Midlands to account for this trend. Temperatures are forecast to be somewhat cooler on Friday as cloud cover should be over the area for much of the day. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Only minor changes have been noted in the guidance for the long term period. Surface high pressure remains in control over the area into the early part of next week. However, some models are picking up on a disturbance moving around the high pressure and bringing some precipitation into the forecast area for Sunday. My confidence is low (~10%) that we'll see any rain from this, but will continue to monitor trends in the next few days. Otherwise, a warming trend is anticipated into the early week ahead. A system approaches the area midweek, bringing us the next chance for precipitation. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR conditions likely. A weak front will backdoor into the region this afternoon and move south of the area tonight. In most model guidance, showers which may develop along the front, remain north and east of the TAF sites. The greatest potential for any showers will be between 21z and 03z but confidence in occurrence is low. Expect winds out of the WSW from 10-15 knots with gusts up to 25 knots possible through the afternoon. After the frontal passage expect winds to turn northerly and decrease to around 5 knots. For Thursday, expect dry weather and light NE winds. EXTENDED AVIATION OUTLOOK...No widespread impacts to aviation expected through Monday. Early morning fog possible at fog prone AGS. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$