Title: http:celebrating200years'noaa'goveventsstormwelcome'html
1Past, Future, and Ongoing Field Experiments in
the Atmospheric Sciences for Western North
Carolina
Douglas Miller, UNCA
http//www.stowy.net/asheville/avlflood.htm
http//celebrating200years.noaa.gov/events/storm/w
elcome.htmlfirsts
2Outline
- Forecast challenges
- Warm season precipitation
- Cold season precipitation
- Field experiments
3Forecast challenges
Western North Carolina
Courtesy Greg Dobson
4Forecast challenges
- Mountain meteorology
- Very localized effects
- Temperature
- Wind speeds
- Wind direction
- Moisture
- Precipitation
http//www.erh.noaa.gov/gsp/localdat/NWFS_discussi
on_group/nwfs_discussion_group.html
5Forecast challenges
- Precipitation
- Where?
- How much?
- In what form?
- Where will it go?
Courtesy NWS
http//www.erh.noaa.gov/gsp/localdat/cases/26June2
006Flooding/26June06Flooding.html
6Forecast challenges
Courtesy Greg Dobson
7Dying tropical systems
Courtesy NWS
8ATMS 373- Introduction
Dying tropical systems
Courtesy NWS
9Snowfall
Courtesy NWS
10Forecast challenges
- The red light, green light game
- In general, you cant forecast
- what you dont see
- what you dont understand
- In weather forecasting, both issues (seeing and
understanding) involve observations
http//www.bbc.co.uk/blogs/ni/religion/
11Forecast challenges
- Warm Season precipitation amount
- Convection
- Organized linear convection
- Propagate into western NC
- Isolated thunderstorms
- Locally generated
- Dying tropical systems
12Forecast challenges
- Warm Season example
- Flash flooding along Twelvemile Creek and the
Hickory Nut Gorge on 26 June 2006 - National Weather Service Greenville
Spartanburg, SC
13Forecast challenges
1200 UTC 26 Jun 2006
14Forecast challenges
1145 UTC 26 Jun 2006
15Forecast challenges
1111 UTC 26 Jun 2006
WESTERN NORTH CAROLINA BAT CAVE 4 N 9.63
THOMASVILLE 9.25 SALUDA 1.5 SW 9.17 ASHE 8.25
HENDERSONVILLE 2 N 7.75 BUSICK 5.43 CULLOWHEE
4.49 BREVARD 4.48 MOUNT MITCHELL 3.63
ASHEVILLE AIRPORT 2.79
16Forecast challenges
17Forecast challenges
Rocky Broad River at Bat Cave, NC
major flooding
flood stage
18Forecast challenges
- All our operational gauges in mountainous areas
tend to be located in easy access locations - Roads follow rivers
- Rivers are in valleys (low elevations)
- Note
19Forecast challenges
http//www.nc-climate.ncsu.edu/cronos/map/index.ph
p
data (observations) void lack of observations
in the mountains, particularly at high elevations
20Forecast challenges
our radar and satellite precipitation estimation
algorithms are generally tuned using observations
located in low elevation regions
Does this cause a bias in our estimates?
21Forecast challenges
- Cold Season precipitation type
- Cold air damming
Courtesy COMET
http//www.meted.ucar.edu/mesoprim/cad/
22Forecast challenges
- Cold Season precipitation type
Courtesy COMET
http//www.meted.ucar.edu/mesoprim/cad/
23Forecast challenges
- Cold Season precipitation type
Courtesy COMET
http//www.meted.ucar.edu/mesoprim/cad/
24Forecast challenges
- Cold Season precipitation type
- Is a warm nose likely?
- If so,
- How deep is the warm air?
- How deep is the cold air next to the ground?
25Forecast challenges
- Cold Season precipitation amount
- Northwest flow snowfall (NWFS)
- http//www4.ncsu.edu/nwsfo/storage/training/assor
ted/lee_nwflow.ppt - Getting snow when you shouldnt
Photo Dr. Baker Perry
26Forecast challenges
- Cold Season precipitation amount
- Snow ingredients
- Cold air
- Moisture
- Lift
http//blogs.trb.com/news/weather/weblog/wgnweathe
r/weather_snap_shots/full/
27Forecast challenges
- Cold Season precipitation amount
- Snow
- Cold air
- Moisture
- Lift
1500 UTC 9 Jan 2007
http//www.erh.noaa.gov/gsp/localdat/cases/9-10Jan
2007NWFS/9-10Jan2007NWFS.html
28Forecast challenges
- Cold Season precipitation amount
- Snow
- Cold air
- Moisture
- Lift
0000 UTC 10 Jan 2007
http//www.erh.noaa.gov/gsp/localdat/cases/9-10Jan
2007NWFS/9-10Jan2007NWFS.html
29Forecast challenges
- Cold Season precipitation amount
- Snow
- Cold air
- Moisture
- Lift
1600 UTC 10 Jan 2007
http//www.erh.noaa.gov/gsp/localdat/cases/9-10Jan
2007NWFS/9-10Jan2007NWFS.html
30Field experiments
Courtesy Greg Dobson
31Field experiments
- Warm Season Pigeon River Basin
- Initiated June 2007
- Ongoing for four years
- PI Dr. Ana Barros, Duke University
- NASA
Precipitation amount
32Field experiments
Courtesy Greg Dobson
33Field experiments
- Warm Season Pigeon River Basin
- Preliminary results
34(No Transcript)
356
4
3800 ft
2
0.8 mi
5
4.5 mi
1
5300 ft
3
4.25 mi
6300 ft
36Field experiments
- Preliminary results
- 14 September 2007
FXUS62 KGSP 140539 AFDGSP AREA FORECAST
DISCUSSION NATIONAL WEATHER SERVICE
GREENVILLE-SPARTANBURG SC 139 AM EDT FRI SEP 14
2007 .SYNOPSIS... THE REMNANTS OF HUMBERTO WILL
MOVE NORTHEASTWARD AND AFFECT THE FORECAST AREA
TODAY. A COLD FRONT WILL CROSS THE AREA FROM THE
NORTHWEST ON SATURDAY...WITH COOL AND DRY HIGH
PRESSURE SETTLING IN BEHIND IT THROUGH THE EARLY
PART OF NEXT WEEK .
37Field experiments
- Preliminary results
- 14 September 2007
- Three precipitation main events
- Record rainfall at AVL
000 SXUS72 KGSP 150649 RERAVL RECORD EVENT
REPORT NATIONAL WEATHER SERVICE
GREENVILLE-SPARTANBURG SC 241 AM EDT SAT SEP 15
2007 ...RECORD DAILY MAXIMUM RAINFALL SET AT
ASHEVILLE... AT THE ASHEVILLE REGIONAL
AIRPORT...ON FRIDAY 3.4 INCHES OF RAIN FELL. THIS
BREAKS THE OLD RECORD OF 2.03 INCHES SET IN
1978. MOORE
38800 am 14 Sep 2007
39-27.1oC 0.51
-36.1oC 0.23
800 am 14 Sep 2007
40Field experiments
800 am
200 am
200 pm
41Field experiments
- 14 Sep 2007 event observations
- For a disorganized convective system
- High elevation rain gauges indicate that higher
elevation doesnt necessarily mean more
accumulated precipitation - What about for a larger scale organized system?
42Field experiments
- Cold Season Asheville area (WWC)
- Initiated Nov 2006
- Ended April 2007
- PI Dr. Douglas Miller, UNC Asheville
- COMET
Precipitation type
43Field experiments
Courtesy Greg Dobson
44Field experiments
- Cold Season Asheville area (WWC)
- Preliminary results
450300 UTC 1 Feb 2007 sea level pressure
H
L
46(No Transcript)
47WWC
48SEMPE Radiosonde Launch 1 1100 UTC Skew-T
created using MATLAB
49Inversion base
Isothermal layer
1100 SEMPE Radiosonde Launch Winds
50AVL meteogram
51P-type observations for AVL and the surrounding
area Warren Wilson College (WWC), Greenville, SC
(GMU), Charlotte, NC (CLT), and Franklin, NC
(1A5) indicate more sporadic precipitation than
had been anticipated at AVL in contrast to the
continuous precipitation observed at surrounding
stations. S snow, Z freezing rain, R
rain, and NO no observation taken. Times in
UTC.
52(No Transcript)
53WV
VA
KY
NC
TN
SC
AL
GA
541.5 km grid spacing topography (decameters)
WWC
AVL
Franklin
55850 hPa Air Parcel Trajectory
56700 hPa Air Parcel Trajectory
57RUC analysis (valid 1000 UTC 1 Feb 2007)
900 hPa dewpoint depression
581100 UTC SEMPE
59Some theories, Asheville region
- Low-level cold air damming was in place initially
- Weak low-level winds and inversion aloft
prevented cold dry air from mixing out overhead
of the AVL region - Southerly winds at AVL
- Easterly winds at WWC
- Mid-level air traveled over the mountains and
deposited its moisture in southwestern North
Carolina before arriving over the AVL region
60Field experiments
- Cold Season Boone area (Poga Mntn)
- Initiated Dec 2007
- Ongoing through cold season (April 2008)
- PI Dr. Baker Perry, App. State University
- Co-PI Dr. Sandra Yuter, NC State University
- UNC-GA
Precipitation amount
61Field experiments
Courtesy Greg Dobson
62Field experiments
- Cold Season Boone area (Poga Mntn)
- Preliminary results
- Site photo here
63Field experiments
- Cold Season precipitation amount
1200 UTC 2 Jan 2008
http//www.hpc.ncep.noaa.gov/html/sfc_archive.shtm
l
64Field experiments
- Cold Season precipitation amount
1200 UTC 2 Jan 2008
http//www.hpc.ncep.noaa.gov/dailywxmap/index_2008
0101.html
65Field experiments
Blue NARR Green NAM Red GFS
0300 UTC 2 Jan 2008
66Field experiments
sublimational cooling
Blue NARR Green NAM Red GFS
0600 UTC 2 Jan 2008
67Field experiments
- Cold Season precipitation amount
12
1200 UTC 3 Jan 2008
ratio 1 to 8 (wet snow)
68Field experiments
- Cold Season precipitation amount
1200 UTC 3 Jan 2008
69Field experiments
- Cold Season precipitation amount
1200 UTC 3 Jan 2008
70Field experiments
GFS
- Cold Season precipitation amount
GFS or NAM as initial conditions
NAM
1200 UTC 3 Jan 2008
71Snow streak
Knoxville
Mt. Mitchell
Asheville
Jan. 3, 2008 1145 EST
Courtesy Grant Goodge
72Mt. Mitchell
Asheville
Jan. 2, 2008 1330 EST
Courtesy Grant Goodge
73Field experiments
- Cold Season Boone area (Poga Mntn)
- Preliminary results- Jan 1-3, 2008 NWFS event
- Moist, unstable layer of air next to the ground
is too shallow in the computer model simulations - Model misses sublimation process 700 hPa level
- Computer model puts too much snow along the peaks
of the mountains in western NC and VA - Computer model puts too little snow downwind of
the Appalachian Mountains - Total simulated precipitation volume may be
nearly correct
74Future field experiments HMT Southeast (April
2010)
http//hmt.noaa.gov/
75Hydrometeorology Testbed Program (HMT)
The national Hydrometeorological Testbed program
will be implemented incrementally in different
regions of the U.S.
Mean annual precipitation (inches)
HMT WEST - Cool Season
American River Basin (Sierra Nevada)
HMT SOUTHEAST All Season, including
Hurricane Landfall
HMT CENTRAL Warm Season
76HMT Observing Systems