Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KRAH 261817 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 215 PM EDT Sat May 26 2018 .SYNOPSIS...
-- Changed Discussion --
High pressure centered over the western Atlantic will extend westward into the Carolinas through Sunday. A deep southerly flow will develop and transport tropical moisture into the area through the middle of the work week, resulting potentially heavy rain.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/... As of 1020 AM Saturday... Latest surface analysis shows a ridge of high pressure established in the western Atlantic with a general south to southwesterly flow across the Carolinas. Further aloft, a narrow ridge of high pressure extends northwest from the subtropical Atlantic to near the Carolina coast. Further west, a trough is noted from the Great Lakes region south into the Tennessee Valley and then into the Gulf of Mexico to near Alberto. Given a deep layer southerly flow, the air mass across central NC has become quite moist with PW values ranging between 1.7 and 1.9 inches. Low level moisture has also increased, resulting in the development of fairly widespread stratus across the area. A well defined short wave, located across the NC Foothills/western Piedmont is generating an area of rain and rain showers that is moving northeast and will spread rain across the western Piedmont and Triad. After this transient feature moves across the area, more typical diurnally forced convection is expected this afternoon and evening with convection focused across the Piedmont and to a lesser extent in the southeast near the sea breeze. With little sustainable forcing, weak to moderate instability and limited shear, no severe thunderstorms are expected but locally heavy rain is possible given the high PW and slow storm motion. Temperatures should range near normal, with highs settling in the low to mid 80s afternoon, and lows remaining near 70 degrees overnight into early Sunday morning. -Blaes && .SHORT TERM /SUNDAY/... As of 330 AM Saturday... Sunday will provide a brief reprieve from the unsettled weather pattern, as central North Carolina finds itself between a frontal zone to the north and the developing tropical system Alberto to the South. Temperatures will rise into the mid to upper-80s during the afternoon, with a few stray showers/storms possibly sneaking south of the VA/NC border, or east of the Blue Ridge Mountains, as the frontal zone becomes more active by late afternoon. Most areas will remain dry and under broken skycover Sunday. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
-- Changed Discussion --
As of 205 PM Saturday... High pressure offshore will ridge northwestward into Central NC while ridging will exist over the Midwest. Meanwhile, Alberto will be approaching the Gulf Coast Monday morning. The outer reaches of Alberto`s precip shield will begin impacting the area as early as Sunday night/Monday morning and with the slow northerly progression of the storm, expect fairly high precipitation chances from then through at least mid-week. It is possible Alberto`s remnants may continue impacting the region as it gets absorbed into the northern stream Thursday/Friday. Beyond that time, forecast confidence drops significantly as it will depend largely on the continued evolution of the system as a northern stream low/trough progressing eastward toward the Atlantic. Of fairly high confidence is the continued advection of warm, moist air into the region throughout this time, resulting in PWATs of 2" or more and MUCAPE values in the afternoon in the 1000-2000 range, mainly across the south and east. Consequently, skies are likely to be overcast through a good portion of the extended forecast period and RH values during the day will bottom out in the 60s but be in the 90-100 percent range overnight. Temperatures will modify through the period. Monday highs in the upper 70s to low 80s and lows in the mid 60s to low 70s. Saturday highs in the mid 80s to around 90 degrees and lows in the low to mid 70s. A flood watch may be needed during this period if forecast rainfall comes to pass and will be watching that closely. Central NC has been primed with wet weather over the past week, though the past day or two there has been a lull in rainfall activity for much of the area.
-- End Changed Discussion --
&& .AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
As of 210 PM Saturday... Through 18Z Sunday: VFR conditions were noted across much of central NC early this afternoon with a few MVFR reports in the Triad as an area of showers departs. Scattered convection will continue to develop and move into the area this afternoon. Another round of scattered showers and storms will be focused in the Triad area affecting the KINT and KGSO terminals between 19Z and 00Z which will shift east toward the KRDU terminal between 22Z and 02Z. More widely scattered showers/storms are expected elsewhere this afternoon and evening. Outside of convection, SCT-BKN cumulus/stratus is expected with cigs of 3-4kft into the evening. Another period of MVFR-IFR stratus is expected between 08 and 14Z tomorrow at the KFAY and KRWI terminals with the potential for a brief period of stratus at the other terminals around daybreak. Any ceiling restrictions will improve during the mid to late morning Sunday with just a limited chance of a shower/storm Sunday afternoon, especially in the Triad. Looking beyond 18Z Sunday: An isolated shower or storm is possible, mainly across the Triad on Sunday afternoon. Much more widespread and impactful adverse aviation conditions are expected to spread north across the area Monday through Thursday with widespread showers and thunderstorms.
-- End Changed Discussion --
&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Blaes NEAR TERM...Blaes SHORT TERM...JM LONG TERM...KC AVIATION...Blaes

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.