NCEP Update: Focus on Winter

Where Americas Climate, Weather and Ocean Services BeginLouis W. UccelliniDirector, NCEP

Northeast Regional Operational WorkshopAlbany, New YorkNovember 1, 2005

OutlineNWS Seamless SuiteSome recent advancementsSeasonal Medium RangeDay 4-7 NDFDDay 1-3 Winter Weather DeskSREF SupportOther update itemsSpace Environment CenterComputerWRFBuilding

CFS 2x/dayCDC 6-10 Day Forecast UpgradeHPC-NDFD, Days 4 -7HPC Winter Weather Desk Days 1-3WRF/SREFNAEFSWeek 2 Hazards Assessment

The NCEP coupled Climate Forecast System (implemented August 24, 2004)Atmospheric componentGlobal Forecast System 2003 (GFS03)T62 in horizontal; 64 layers in verticalOceanic componentGFDL MOM3 (Pacanowski and Griffies, 1998) Once per day couplingSea ice extent based on observed climatology60 runs per month used for a 9 month ensemble predictionModel now run twice per day

Without skill maskCFS SeasonalPrecip Forecast (mm/month)

With skill mask If anomaly correlation between forecast and observed conditions over the 1982-2003 period is below 0.3, values are not shown

CFS SeasonalPrecip Forecast (mm/month)

Without skill maskCFS SeasonalTemp Forecast (deg/month)

With skill mask If anomaly correlation between forecast and observed conditions over the 1982-2003 period is below 0.3, values are not shown

CFS SeasonalTemp Forecast (deg/month)

CPC Winter Season Forecast2005-06

North American Ensemble Forecast System

Combines global ensemble forecasts from Canada & USANow: CAN 16/day out to 10 days, US 40/day out to 16 days06 CAN 40/day out to 16 days, US 56/day out to 16 days07 CAN 40/day out to 16 days, US 80/day out to 16 daysGenerates products forIntermediate users: weather forecasters at NCEP Service Centers and WFOsSpecialized users: hydrologic applications in all three countriesEnd users: forecasts for public distribution in US, Canada (MSC) and Mexico (NMSM)Future activitiesAdding products (probabilistic in nature)Incorporating ensemble data from other centers (e.g., FNMOC)Unified evaluation/verification procedures

International project to produce operational multi-center ensemble products

NAEFS ProductsNAEFS basic product list11 functionalitiesEnsemble mean, spread, probabilities, etc50 variablesU,v,t,z,CAPE, precip type, etc.7 domainsGlobal, NH, NA, CONUS, SA Carib., Africa300-400 products requested by users (will be supplied via priority order)GraphicsNAWIPS (March 06)NCEP Model Web Page as early as March 2006 on experimental basisGridsNAWIPSftp site (GRIB2) in planning phase (Mar 06)NDGD in planning phase (Mar 06)Still working availability issues - first priority: intermediate users

ENSEMBLE 10-, 50- (MEDIAN) & 90-PERCENTILE FORECAST VALUES (BLACK CONTOURS) AND CORRESPONDING CLIMATE PERCENTILES (SHADES OF COLOR) 90 percentile10 percentile50 percentile

8-14 day Outlook6-10 day OutlookHazards AssessmentOutlooks for period of rainfall fromremnants of Tropical StormTammy

6-10 day forecast valid Oct 30 Nov 3, 2005TemperaturePrecipitationTemperaturePrecipitation8-14 day forecast valid Oct 29 Nov 4, 2005

4-7 Day HPC Gridded Forecast The following grids are being generated daily

Experimental grids can be viewed herehttp://www.hpc.ncep.noaa.gov/5km_grids/5km_gridsbody.htmlProduction Methodology documentationhttp://www.hpc.ncep.noaa.gov/5km_grids/medr_5km_methodology.pdfAll grids extend offshore to cover the coastal watersVerification program underway Maximum temperatureMinimum temperature12 hour PoP6 hourly dew point

6 hourly wind (direction and speed)6 hourly cloud cover12 hourly weather

HPC/NDFD HighlightsFor decades HPC provided day 3 - 7 guidanceMax Temp, Min Temp, 24 hr (later 12 hr) Pop, surface progsSpring 2004 - HPC asked to provide forecasts for additional fields including dew point, sky cover, wind direction and speed, and precipitation typeHPC requested to deliver these forecasts as 5 km gridsHPC began providing these fields in June 2004.

MethodologyHPC has 2 forecasters/shift preparing day 4 7 forecasts (one shift/day)One prepares surface progs and writes the narrativeSecond prepares the max/min temperatures and PoPsHPC uses N-AWIPS to generate forecastsForecasters start with MOS max/min temps and MOS12 hr PoPsForecasters can edit 384 stations; usually edit ~ 20 - 25% of stations for a particular forecastUsually focus on areas they expect MOS to be deficient due to synoptic scale considerationsAdditional fields increased the number of grids from 16 to 102No additional forecasters made available Only solution was to generate additional fields automaticallyBasic philosophy is to generate a set of grids consistent with the manually generated forecasts (H, L, Fronts)Each additional field is generated from a manually prepared HPC productCurrently, these additional fields are not touched by a forecaster

Grid ProductionMax/min temperature grids are produced by interpolation of manually prepared point forecasts to a grid with Prism climatology as a backgroundPoP grids are interpolated from HPC modified stationsDew points use the HPC temperature forecasts and MOS ensemble with Prism climatology as a backgroundCloud cover is based on HPC PoPs and max tempsWinds are based on HPC surface progsPrecipitation type is based on HPC max/min temperature forecasts and on PoPs (for aerial coverage)WFOs provide input between preliminary and final product release through 12Planet

Verification ResultsIn general, HPC point forecasts are as good as or better than MOS and NDFDHPC winds are poorest of all HPC gridsThese results have been consistent from month to month

How HPC adds value to Day 4 - 7HPC shows 5 10% improvement over MOSIs this a good use of resources?

How HPC adds Value to Day 4 7 (Cont.)A Big win or Big loss occurs when HPC beats or looses to MOS by > 10 degrees.In those cases, HPC is better than MOS ~ 80 percent of the time (sample size ~ 35 - 40)HPC BIG WIN VS BIG LOSS PERCENTAGES COMPARED TO GFS MOS 2004% of time

4-7 Day Gridded Products4 day validNov 1Maximum Temperature5 day valid Nov 26 day valid Nov 37 day valid Nov 4

4-7 Day Gridded Products4 day validNov 1Minimum Temperature5 day valid Nov 26 day valid Nov 37 day valid Nov 4

IssuesTime of release of forecastsSome WFOs want HPC to issued grids earlierHPC starts with MOS rather than previous forecastField prefers less flip-floppingHow involved do forecasters need to be?Are post-processed grids good enough?Should HPC provide probabilistic info?QPF exceedance valuesDay 4 7 ranges in addition to best guessHow is collaborative approach sustained?

Future PlansContinued improvement of methodologyBetter algorithms for post processed fieldsFaster processing of grids for earlier deliveryBetter hardwareOptimize processingExpand coverage to OCONUSExplore other ways of creating sensible weather gridsGreater use of ensembles to create grids from selected blend (NAEFS)Forecasters focus on model selection and modification

Winter WeatherGoals of 4 year experiment from 2001- 2004:Improve Winter Weather Services to the public through coordination of the winter weather watches/warnings with National guidance productsTest short range ensemble for their applications to winter weather forecastingMotivation:Jan 24-25, 2000; December 30, 2000: March 4-6, 2001WWD operational September 15, 2004 NWS Winter Weather Desk

Regional StatsTo date NWS FY05 LT is 18h, 3h greater than GPRA goal of 15h* Oct - Mar

ERWWE1 (01-02)WWE2 (02-03)WWE3 (03-04)WWD (04-05)# WFOs82323ALLPOD.89.90.92.92FAR.33.30.32.30CSI.62.65M.66LTWarn13151821

CRWWE2 (02-03)WWE3 (03-04)WWD* (04-05)# WFOs833ALLPOD.90.88.92FAR.40.45.32CSI.57.51.65LTWarn131317

WRNonWWE3 (03-04)WWE3 (03-04)WWD* (04-05)# WFOs1210ALLPOD.86.88.88FAR.26.27.30CSI.66.67.64LTWarn121416

SRNonWWE3 (03-04)WWE3 (03-04)WWD (04-05)# WFOs411ALLPOD.84.92.90FAR.37.38.39CSI.57.59.57LTWarn599

February 28th 2005 Event

February 28, 2005 Event48 hr prob of >424 hr prob of >424 hr storm track24 hr snowfall

Winter Weather Desk StatusTime line: Sep 15 April 1ParticipantsNCEP HPCProvide SREF based Winter Wx guidanceCollaborate with WFOs (Chat Room Technology)WFOs All CONUS WFOsUse guidance from NCEP to produce coordinated Winter Storm Watches/WarningsProducts: http://www.hpc.ncep.noaa.gov/wwd/winter_wx.shtml24 h probability (low, moderate, high) of meeting/exceeding 4, 8, 12 snow, 0.25 freezing rain (for day 1, 2, 3)72h Low tracks graphic and discussion

Winter Weather Desk Status (cont.)Off to a good startBegan operational status 00Z Sept 15Three significant event so far: all verified exceptionally well for snowfall amount and watch/warning criteria Ern MT into the Dakotas (Oct 4-5) Collaboration conducted with FGF, BYZ, GGW, BIS, UNRFront Range Event (Oct 9-10)Collaboration conducted with CYS and PUBNortheast Event (Oct 24-25)Collaboration conducted with RLX, OKX, PHL, LWXEarly challengesStaffing WWD during active tropical season !Training HPC staff (vets and newbies) and WFOs

Day 2 Probability of SnowValid 12Z Oct 10 12Z Oct 11> 8 in> 12 in

Short Range Ensemble Forecast15 members twice per day87 hrs from 9 and 21ZResolution 32km/60 levelsMean and spread charts available for forecaster useDeveloping products on probability of snow and ice accumulationhttp://wwwt.emc.ncep.noaa.gov/mmb/SREF/SREF.html 0.01 snow

SREF Upgrades FY2005Improved and new products (Convective, Aviation, Winter Weather) Output SREF forecasts for Alaska and HawaiiAdd RSM BUFR filesCommon WRF post-processor

FY2006Add six members twice per day (WRF ARW & WRF NMM) Run SREF 4 times per day (03, 09, 15 and 21 UTC)Implement Grid Based Bias CorrectionImprove Probabilistic FVS verificationDevelop spread information for NDGDAdd WRF BUFR FilesImplement ensemble mean BUFR files

Probability event will last more than 12, 24, 48 hrs Probability visibility will be reduced to 1/2, 1/4, or 1/8 mile in winter precipProbability winter precip rate will be more than 1, 2, or 3" per hr Probability road sensor will detect winter precip (relative to normal) Probability Blizzard Criteria will be met Probability Freezing Rain .01" or more will accumulate on any surface Probability NWS Winter Storm Warning criteria will be met (under construction) New Impact Graphics from SREF

National Operational Hydrologic Remote Sensing Center Analysis Snow Depth as of 12Z Oct 26

Low tracksValid 12z Oct 24, 2005Thru 12Z Oct 27, 2005

>12 in>8 in>4 in48 hour probability of snowValid 12Z Oct 25 12Z Oct 26

Experimental WWD Snow Accums downscaled using PRISM data

Probability Snow Detected on Roads

NCEP: Other Update Items Space Environment Center Computing Capability WRF Update Building

Space Environment CenterSEC formally joined NCEP/NWS/NOAA on January 9Their addition helps foster a seamless suite of operational products from the Sun to the SeaProvides space weather alerts and warnings for disturbances that can affect people and equipment working in space and on EarthService/Science linkage offers many exciting challenges for future growth to insure the delivery of weather/ocean/climate products to a diverse and increasingly sophisticated user community (e.g., climate, aviation)

Computing Capability

Receives Over 210 Million Global Observations DailySustained Computational Speed: 1.485 Trillion Calculations/SecGenerates More Than 5.7 Million Model Fields Each DayGlobal Models (Weather, Ocean, Climate)Regional Models (Aviation, Severe Weather, Fire Weather)Hazards Models (Hurricane, Volcanic Ash, Dispersion)2.4x upgrade operational on January 25, 2005Backup in Fairmont, WV operational on January 25, 2005Commissioned/Operational IBM Supercomputer in Gaithersburg, MD (June 6, 2003)$26.4M/Year Investment

GFSCFSGFDLSREF NAM - EtaNOAH Land Surface ModelDispersionAir Quality2005 NCEP Production Suite Atmospheric Model DependenciesGGSI

WRF-NMMWRF-ARWETARSM L D A S Sev WxWRF-NMMWRF-ARWGENSEDASRUC

WRF Implementation ScheduleHiResWindow for Hazardous Weather: (ARW and NMM) Implemented operationally at NCEP on 6/28/05 (~5 km)WRF SREF members: Operational FY06 (1st Qtr)North American WRF: Operational in FY06 (3rd Qtr)WRF SREF: Fully Operational in FY07*Hurricane WRF: Operational in FY07*Rapid Refresh WRF: Operational in FY07*WRF Chem: Beyond FY08** As resources allow

GFSCFSHurricaneWRFSREF NAM - WRFNOAH Land Surface ModelDispersionChem WRF*Air Quality2007 NCEP Production Suite Atmospheric Model DependenciesRapid Refresh WRFGGSI

RGSIWRF-NMMWRF-ARWRSM ? L D A S Sev WxWRF-NMMWRF-ARW*FY08GENS

NOAA Center for Weather and Climate PredictionDefined requirements for 268,762 RSF Includes housing 800 Federal employees, contractors, and visiting scientists 5 NCEP CentersNESDIS research and satellite servicesOAR Air Resources LaboratoryBegin move to new facility September 07 and complete by Feb 08

SummaryMaking progress with collaborative forecastingAcross entire spectrum from climate to weatherEvent-driven to standard day-to-day forecastsNCEP Service and Modeling Centers are ready for winterMaking progress with a community modeling approach across all time scales increasingly ensemble basedNCEP infrastructure issues being addressedComputerBuildings (UMD and OU (SPC))

Background Slides

NOAA Center for Weather and Climate Prediction

timelineIf anomaly correlation between forecast and observed conditions over the 1982-2003 period is below 0.3, values are not shownEssentially, one forecaster is creating all of the sensible weather grids, although the two forecasters do work together to asses the models and decide on a model of choice or a blend.

Verification has shown that HPC can best improve on MOS by focusing on targets of opportunity, areas where we feel the GFS (and GFS MOS) is not the best choice for the synoptic scale solution. We do not routinely tweak temperatures or PoPs in areas where we do not see a strong reason to modify MOS. We do not have the expertise to account for local features, except to the extend they are incorporated into MOS and Prism. For this reason, HPC generally only modifies about 25% of the stations. (See graph on page 12.)

All of the automated products are based to some extent on an HPC modified field.

Dew Point grids are calculated using a slightly different methodology than the other grids. The algorithm looks for the ensemble member whose temperature is closest to the HPC (manually modified) temperature, then uses the dew point from that ensemble member. A check is made to ensure the dew point doesnt exceed the temperature. Then the grid is created using the Prism data as background in the same way the temperature grids are made.

Note that precip type is different than the GFE Weather field. We only create 4 categories, rain, snow, mixed, or convective.

A more complete explanation of the creation of these products is at http://www.hpc.ncep.noaa.gov/5km_grids/medr_5km_methodology.pdf .While HPC has verification of day 3 7 max/min temperatures and PoPs back to the early 1970s (See http://www.hpc.ncep.noaa.gov/html/hpcverif.shtml#medmin) we only began verifying our point forecasts of dew point, sky cover, winds, and precipitation type in October 2004.This chart shows the average improvement of HPC minimum temperature forecasts over MOS for those stations that HPC modifies. Only stations that HPC has modified is included in this calculation. Similar charts for max temperature and PoPs are available at http://www.hpc.ncep.noaa.gov/html/hpcverif.shtml. The bottom half of the graph shows the average number of stations modified. Note that the data is presented by month, quarter, and year to date. The point for showing this chart is that on the average, HPC improvement is quite modest (but consistent), at about 5% for the year to date. This chart illustrates another way of evaluating the HPC day 4 7 guidance. The data for this chart is derived from verification for the days on which the HPC either beat MOS by at least 10 points or lost by at least 10 points. These are the days when HPC made significant deviations from MOS. The number of cases was around 35 40. The chart shows that on those occasions, HPC won a large percentage of the time. The Top 10 each category includes the 10 biggest wins or losses for each parameter. The HPC winning percentage was even better on those cases.

The message from these charts is that HPC adds value best in cases when MOS errors are greater. It can be argued that must of the HPC value is in identifying the big busts more than in the day to day tweaking of MOS.Many offices have asked HPC to send the grids out earlier, but we havent gotten a consistent message from the regions. While some offices seem to want us to provide the grids an hour earlier, others would like to have the gridded guidance available for the midnight shift. We have asked for guidance from WSH before we make significant changes to our schedule. Our concern is that if we send our grids out much earlier, we will compromise the quality of the forecast. Forecasters need time to digest all of the model data and asses the performance of the models prior to preparing their forecasts.

We also feel that we can put out a better forecast by starting with the latest MOS rather than the previous forecast. This sometimes results in HPC forecasts flip-flopping more that the WFO would like. We are developing better tools to let our forecasters know when they change a previous forecast; this may help reduce the flip-flopping.

HPC is developing a confidence factor for QPF. The product is still under development and can be seen in near real time at http://www.hpc.ncep.noaa.gov/qpfci/qpfci.shtml. Click on the link Information about the 6-hour forecasts for an explanation of how they are made. We plan to produce a subset of these products for operational distribution early in 2006. HPC is working with the WFOs to identify and fix shortcomings to the gridded products. We have made several improvements based on feedback from the WFOS. This feedback is especially important since we cannot yet view our grids on AWIPS. We are near the end of the upgrade list have have not yet upgraded to OB5.

HPC is working on some improvements to our grid generation processing that should speed up the delivery of the grids. We have obtained faster servers and hope to transfer processing to them this Fall. This could cut the 1 hour processing time in half.

Once we validate the usefulness of these grids over CONUS, we would like to extend them to the OCCUNS. Forecaster resources are likely to be an issue however.

In the long run, we would like to develop tools to allow the HPC forecasters to do what they do best, focus on model interpretation and synoptic scale modifications to guidance. We would like to develop a system in which the sensible weather falls out of the synoptic scale modifications made by the forecasters rather than have the forecaster directly edit sensible weather fields. We hope to work with EMC on some possible ways to implement such a methodology.