Marine Weather and Tide Forecast for Rocky Mount, NC

NEAR TERM /THROUGH TONIGHT/
As of 950 PM Friday...

Aloft, as of the 00Z upper air analyses, high pressure at H5 was centered off the FL coast, with a low/trough over MO. The H7 and H85 remain saturated, with weak flow throughout the column. Mid-level disturbances riding the ridge will continue lifting enewd across portions of the area this eve/early tonight, possibly helping sustain convection NW of the Triad and over SC as it drifts enewd but with central NC worked over pretty well today, latest hi-res guidance suggests the convection should gradually fall apart over the next several hours. Given the slow but heavy nature of the convection, any showers/storms that do hold together and move into the area could produce locally heavy rainfall. Still expect lows in the upper 60s to low 70s. Widespread stratus and patchy fog should continue to develop and spread through daybreak.

SHORT TERM /SATURDAY THROUGH SUNDAY/
As of 250 PM Friday...

*Persistence forecast with isolated flash flooding risk Saturday afternoon and evening

A persistent deep SWLY flow between the weakening compact low and upper trough currently over the lower/middle MS Valley and subtropical ridging off the Florida coast, will maintain anomalously moist conditions across the region. PWATs of 2-2.25"(95-98th percentile)will support pockets of heavy rainfall once again on Saturday.

The forcing mechanisms driving today's convective rain chances will continue to provide the focus again on Saturday---1)Daytime heating within a moisten laden environment---2) Episodic PVA as weak disturbances pass through the area--- 3)mesoscale convergence zones, including seabreeze boundaries and residual outflow boundaries from prior convection.

Pockets of heavy rain and isolated flash flooding will remain the primary threat. Urban areas and places with increasing soil saturation due to the previous day of heavy rainfall would be most at risk for flooding.

While weak shear and moist lapse rates aloft will limit storm organization, isolated pulse-type strong to severe storms cannot be ruled out.

Widespread cloud cover and rain chances will temper daytime temperatures. Highs mainly in the mid 80s.

Storm chances will decrease through the evening and overnight hours, though isolated showers may linger into early Saturday morning due to deep moisture in place. Continued muggy with overnight lows in the upper 60s to lower 70s with patchy fog possible.

LONG TERM /SUNDAY THROUGH FRIDAY/
As of 255 PM Friday...

* Above-normal rain chances Sun-Tue will lower to more typical scattered showers/storms Wed-Sun, with increasing heat.

Confidence is high that our temperatures will stay at or above normal next week. A mid level Bermuda anticyclone will extend westward across FL and the Southeast coast through at least Thu, keeping us within a weak steering flow. One weak perturbation tracking through the Ohio Valley will dampen as it approaches W NC late Sun then moves through our northern sections and VA through Mon. This should make Sun and Mon our likely wettest days, given the added forcing for ascent provided by DPVA aloft (weak due to the fairly light flow) and an uptick in jet-induced upper divergence, and the persistence of above-normal PW (125-150% of normal, around 1.75-2.0"). The mid level anticyclone should hold the surface frontal zone to our N, winding from the Midwest through the Mid Atlantic, keeping us under an offshore-centered surface ridge, marred only by a weak lee trough over the W Piedmont and Foothills.
With weak flow and high moisture through the column, the risk of localized flooding will persist, with slow-moving shower/storm clusters possible and LCL-0C depth reaching aoa 4 km at times, favoring warm rain processes. Expect highs both Sun and Mon in the mid 80s to around 90, and morning lows in the upper 60s to mid 70s.

Behind this weak wave, the mid level ridge will build over NC with renewed vigor through the mid to late week, helping to warm and stabilize the mid levels and pushing low level thicknesses to around 10 m above normal. A second very weak wave will scrape by our W and N sections late Tue into Tue night, thus pops should stay elevated esp in our NW Tue. But otherwise, we'll see a downturn in pops to more typical coverage, scattered storms largely confined to early afternoon through mid evening, for Wed through Thu. With the warmth aloft and slightly better heating compared to earlier in the week, temps should get pretty toasty, with highs rising from the upper 80s/lower 90s Tue to the low-mid 90s Wed/Thu. With afternoon dewpoints mostly in the upper 60s to mid 70s, heat indices in the upper 90s to low 100s will be common both days.

By Fri, more substantial mid level troughing over the Upper Midwest during the middle of the week is expected to shift eastward and move through the Northeast/Mid Atlantic region. Model solutions begin to diverge with the speed and amplification of this trough by early Fri, without a clear winner, although, historically, models often break down this sort of ridging aloft too quickly. With the lack of a strong surface cold front with this feature, will keep temps above normal Fri, in the upper 80s to lower 90s. -GIH

AVIATION /23Z FRIDAY THROUGH WEDNESDAY/
As of 630 PM Friday...

Most of the deeper convection has come to an end with some lingering isolated showers over the Triad and light rain over FAY. Much of this activity should slowly fade over the next few hours with the stratiform rain likely the last to cease and/or move out of the terminals. No major changes with the 00z TAFs as cigs should drop tonight to MVFR to IFR at all terminals with varying degree of timing and confidence. Given the heavy rain over the FAY terminal and slow departure of rain until after sunset, they have the potential to go down to IFR quickly, so adjusted timing quicker by a couple hours ahead of guidance. Additional scattered to locally numerous showers and isolated storms will again be possible Sat afternoon with equal chances at all terminals.

Outlook: Daily afternoon shower and storm chances will exist into early next week under a typical summertime pattern, along with morning fog/stratus. The best chance of storms appears favored Sat and Sun. Coverage in showers/storms may decrease Tues into Wed, becoming more hit-or-miss.

EQUIPMENT

...Computer System Upgrade at NWS Raleigh from June 16th through 18th...

The National Weather Service Raleigh Weather Forecast Office in Raleigh will be conducting a required, scheduled update to our Advanced Weather Interactive Processing System (AWIPS)
computer system. NWS offices use AWIPS to display and integrate weather and water information, and to send life-saving information, such as weather and water warnings, to the public.

AWIPS is updated periodically, but this update is comprehensive and requires that the system be taken completely offline for approximately three days, from the morning of Monday, June 16th through the afternoon hours of Wednesday, June 18th. During that time, NWS Raleigh forecasters will produce and disseminate products for the area using the AWIPS system at one of our backup offices at NWS Blacksburg, VA. No impacts to our core services of forecast products and weather watches, warnings and advisories are expected during this period.

A few of our services will be impacted as they originate only from AWIPS facilities at NWS Raleigh, namely:

* NOAA Weather Radio broadcast: The following NOAA Weather Radio transmitters, programmed by NWS Raleigh, will be off the air during most of the AWIPS update:

Buck Mountain (WWF 60 - 162.500 mhz)
Chapel Hill (WXL 58 - 162.550 mhz)
Ellerbe (WNG 597 - 162.400 Mhz)
Garner (WNG 706 - 162.450 mhz)
Henderson (WNG 586 - 162.500 mhz)
Tarboro (WXL 59 - 162.475 mhz)
Winston-Salem (WXL 42 - 162.400 mhz)

* Climate: Data will be updated in a limited fashion from Monday afternoon, June 16th through Wednesday, June 18th. Climate graphs for the Raleigh Forecast Area at https:// www.weather.gov/rah/climatePlots will not be updated.

* Graphical Hazardous Weather Outlook images normally at www.weather.gov/erh/ghwo?wfo=rah will not be updated.

* The Weather Story available at https:// www.weather.gov/rah/weatherstory will not be updated.

* Water level forecast services will be degraded due to a less frequent update cycle. Forecasts will remain at https://water.noaa.gov/wfo/rah through this period.

* NWS Raleigh will remain operational and staffed while AWIPS is offline, taking public and partner phone calls, communicating via social media, and performing other functions that can be completed without AWIPS.

We apologize for any inconvenience. Please direct any questions to Jonathan Blaes at jonathan.blaes@noaa.gov

RAH WATCHES/WARNINGS/ADVISORIES
None.